Tuesday, July 7, 2015

Cessna 150M, N3601V and General Dynamics F-16C Fighting Falcon: Fatal accident occurred July 07, 2015 in Moncks Corner,South Carolina

National Transportation Safety Board - Aviation Accident Final Report: http://app.ntsb.gov/pdf 

National Transportation Safety Board  -  Docket And Docket Items: http://dms.ntsb.gov/pubdms

NTSB Identification: ERA15MA259B
14 CFR Armed Forces
Accident occurred Tuesday, July 07, 2015 in Moncks Corner, SC
Probable Cause Approval Date: 11/15/2016
Aircraft: LOCKHEED-MARTIN F-16CM, registration: 96-0085
Injuries: 2 Fatal, 1 Minor.

NTSB investigators traveled in support of this investigation and used data obtained from various sources to prepare this aircraft accident report.

The pilot of the F-16, who was operating on an instrument flight rules (IFR) flight plan, was in contact with air traffic control (ATC) and was provided radar vectors for a practice instrument approach to Charleston Air Force Base/International Airport (CHS), Charleston, South Carolina; the F-16 descended to an altitude of about 1,600 ft mean sea level as instructed by the air traffic controller. Shortly thereafter, the Cessna departed under visual flight rules (VFR) from a nearby nontowered airport; the Cessna pilot was not in contact with ATC, nor was he required to be, and had not requested traffic advisory (flight-following) services. As the Cessna continued its departure climb, the airplanes converged to within about 3.5 nautical miles (nm) laterally and 400 ft vertically, triggering a conflict alert (CA) on the controller's radar display and an aural alarm. About 3 seconds later, the air traffic controller issued a traffic advisory notifying the F-16 pilot of the position, distance, and indicated altitude of the radar target that corresponded to the Cessna, stating that the aircraft type was unknown. When the F-16 pilot replied that he was looking for the traffic, the controller issued a conditional instruction to the F-16 pilot to turn left if he did not see the airplane. The F-16 pilot did not see the airplane and responded, asking "confirm two miles?" The controller responded, "if you don't have that traffic in sight turn left heading 180 immediately." As the controller began this transmission, the F-16 pilot initiated a standard rate (approximately) left turn using the autopilot so that he could continue to visually search for the traffic; however, the airplanes continued to converge and eventually collided about 40 seconds after the controller's traffic advisory notifying the F-16 pilot of traffic. (Figure 1 in the factual report for this accident shows the calculated flight tracks for the Cessna and F-16.)

Air Traffic Controller and F-16 Pilot Performance

During postaccident interviews, the controller reported that when she observed the Cessna's target on her radar display as it departed, she thought that the airplane would remain within its local traffic pattern, which was not the case. Therefore, it was not until the airplanes were within about 3.5 nm and 400 vertical ft of one another that the controller notified the F-16 pilot of the presence of the traffic by issuing the traffic advisory, which was about 3 seconds after the ATC radar CA alarmed. (Federal Aviation Administration [FAA] Order 7110.65, Air Traffic Control, paragraph 2-1-21, "Traffic Advisories," states, in part, that a controller should "Unless an aircraft is operating within Class A airspace or omission is requested by the pilot, issue traffic advisories to all aircraft (IFR or VFR) on your frequency when, in your judgment, their proximity may diminish to less than the applicable separation minima. Where no separation minima applies, such as for VFR aircraft outside of Class B/Class C airspace, or a TRSA [terminal radar service area], issue traffic advisories to those aircraft on your frequency when in your judgment their proximity warrants it. …") 

When the controller issued the traffic advisory, about 40 seconds before the eventual collision, the F-16 and the Cessna had a closure rate of about 300 knots. If the F-16 pilot had reported the Cessna in sight after the controller's traffic advisory, the controller likely would have directed the F-16 pilot to maintain visual separation, which is a common controller technique to separate aircraft. While the controller tried to ensure separation between the airplanes, her attempt at establishing visual separation at so close a range and with the airplanes converging at such a high rate of speed left few options if visual separation could not be obtained. 

The options available to the controller when issuing instructions to the F-16 pilot to avoid the conflict included a turn, climb, some combination thereof, or not issuing an instruction at all. (An instruction to descend was not an option because the F-16 was already at the minimum vectoring altitude for the area.) The controller indicated in a postaccident interview that she chose not to instruct the F-16 to climb because the altitude indicated for the Cessna's radar target was unconfirmed (the Cessna pilot had not contacted ATC). An element informing the controller's decision-making as to which instruction to provide was likely the flow of other traffic into the airport at that time. Arriving aircraft, including the accident F-16, were being sequenced to runway 15 via the final approach course extending from the approach end of the runway. Given the traffic flow, the left turn instruction to the F-16 would have kept the airplane on a heading closer toward, rather than farther from, its destination and would have made returning the F-16 to the intended final approach course much easier. However, the controller's instruction to the F-16 pilot to turn left required the F-16's path to cross in front of the Cessna. Although this decision was not contrary to FAA guidance for air traffic controllers, it was the least conservative decision, as it was most dependent on the F-16 pilot's timely action for its success.

Further, the controller issued the instruction to turn left if the F-16 pilot did not have the Cessna in sight. The F-16 pilot responded to the controller's conditional instruction with a question ("confirm two miles?") that indicated confusion about the distance of the traffic. The F-16 pilot's attempt to visually acquire the Cessna per the controller's conditional instruction likely resulted in a slight delay in his beginning the turn. The collision likely would have been avoided had the F-16 pilot initiated the left turn, as ATC instructed, when he realized that he did not have the traffic in sight. About 7 seconds elapsed between the beginning of the controller's first conditional instruction to turn and the beginning of her subsequent conditional instruction to the F-16 pilot to turn "immediately." Analysis of the radio transmission recordings and the F-16's flight recorder data showed that, as the controller was making the subsequent conditional instruction, the F-16 pilot began turning to the left, which pointed his aircraft toward the Cessna. 

Due to the closure rate, the close proximity of the two airplanes, and human cognitive limitations, the controller did not recover from her ineffective visual separation plan, which placed the airplanes in closer proximity to each other, and switch to an alternative method of separation. The controller's best course of action would have been to instruct the F-16 pilot to turn before the airplanes came into close proximity with each other and preferably in a direction that did not cross in front of the Cessna's path.

In postaccident interviews, the controller stated that when she issued the command to the F-16 pilot to turn left "immediately," she expected that the F-16 pilot would perform a high performance maneuver and that she believed that fighter airplanes could "turn on a dime." The FAA's Aeronautical Information Manual (AIM) Pilot-Controller Glossary defines "immediately" as a term used by ATC or pilots "when such action compliance is required to avoid an imminent situation." Further, the AIM states that controllers should use the term "immediately" to "impress urgency of an imminent situation" and that "expeditious compliance by the pilot is expected and necessary for safety." As described above, the F-16 pilot did not meet her expectation that the turn be conducted at a greater-than-standard rate. 

The controller's expectation of the F-16 pilot's performance was based on her assumption that a fighter airplane would perform a high performance turn to the heading; however, this expectation of performance was not clearly communicated. Based on the controller's instructions and the actions of the F-16 pilot in response, it is clear that the term "immediately" held different expectations for both parties. Although the controller's use of the term "immediately" was in keeping with FAA guidance, further clarification of her expectation, such as directing the pilot to "expedite the turn," would have removed any ambiguity.

See-and-Avoid Concept

According to 14 Code of Federal Regulations 91.113, "Right-of-Way Rules," "when weather conditions permit, regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft." The concept that pilots are primarily responsible for collision avoidance was similarly stressed in US Air Force training documents. In addition, FAA Advisory Circular (AC) 90-48C, "Pilots' Role in Collision Avoidance," which was in effect at the time of the accident, stated that the see-and-avoid concept requires vigilance at all times by each pilot, regardless of whether the flight is conducted under IFR or VFR. (AC 90-48D replaced AC 90-48C in 2016 and contains the same statement.)

The see-and-avoid concept relies on a pilot to look through the cockpit windows, identify other aircraft, decide if any aircraft are collision threats, and, if necessary, take the appropriate action to avert a collision. There are inherent limitations of this concept, including limitations of the human visual and information processing systems, pilot tasks that compete with the requirement to scan for traffic, the limited field of view from the cockpit, and environmental factors that could diminish the visibility of other aircraft.

Factors Impacting the Pilots' Ability to Detect Other Traffic

The collision occurred in a relatively low-density air traffic environment in visual meteorological conditions (VMC). The Cessna was equipped with an operating transponder and single communication radio but was not equipped with any technologies in the cockpit that display or alert of traffic conflicts, such as traffic advisory systems, traffic alert and collision avoidance systems, or automatic dependent surveillance-broadcast systems. The Cessna had departed from a nontowered airport and was still in close proximity to the airport when the collision occurred. The Cessna pilot had not requested or received flight-following services from ATC at the time of the collision, nor was he required to do so. Based on his proximity to the departure airport, it is reasonable to expect that the Cessna pilot likely was monitoring that airport's common traffic advisory frequency (CTAF) for awareness of airplanes in the vicinity of the airport, as recommended by the FAA's AIM. Based on statements from the Cessna pilot's flight instructor and from his logbook entries, which both cited past experience communicating with ATC, it is also reasonable to assume that had the collision not occurred, the pilot likely would have contacted ATC at some point during the flight to request flight-following services.

Due to the Cessna's lack of technologies in the cockpit that display or alert of traffic conflicts and the pilot's lack of contact with ATC, his ability to detect other traffic in the area was limited to the see-and-avoid concept. While not required, had the Cessna been equipped with a second communication radio, the pilot could have used it to contact ATC while still monitoring the departure airport's CTAF. Had the Cessna pilot contacted ATC after departing and received ATC services, the controller would have had verification of the Cessna's altitude readout and its route of flight, which would have helped her decision-making process. The controller also could have provided the Cessna pilot awareness of the F-16. 

The F-16 was operating under IFR in VMC. The F-16 pilot's ability to detect other traffic was limited to the see-and-avoid concept, supplemented with ATC traffic advisories. While the F-16 pilot could use the airplane's tactical radar system to enhance his awareness of air traffic, it was designed to acquire fast-moving enemy aircraft rather than slow-moving, small aircraft and was thus unable to effectively detect the Cessna. (The radar system did detect a target 20 miles away, which is likely what led the F-16 pilot to question the location of the traffic that the controller had indicated was 2 miles away.) The F-16 was not otherwise equipped with any technologies in the cockpit that display or alert of traffic conflicts. The F-16 pilot did eventually visually acquire the Cessna but only when the airplanes were within about 430 ft of one another, about 1 second before the accident.

A factor that can affect the visibility of traffic in VMC is sun glare, which can prevent a pilot from detecting another aircraft when it is close to the position of the sun in the sky. For the F-16 pilot, the sun would have been behind and to his left as the airplanes approached one another. Although the Cessna pilot would have been heading toward the sun, the sun's calculated position would likely have been above a point obstructed by the Cessna's cabin roof and would not have been visible to the Cessna pilot. Thus, sun glare was not a factor in this accident.

Aircraft Performance and Cockpit Visibility Study

Our aircraft performance and cockpit visibility study showed that, as the accident airplanes were on converging courses, they each would have appeared as small, stationary, or slow-moving objects to the pilots. Given the physiological limitations of vision, both pilots would have had difficulty detecting the other airplane. Specifically, the study showed that the Cessna would have appeared as a relatively small object through the F-16's canopy, slowly moving from the center of the transparent heads-up display (HUD) to the left of the HUD. As the F-16 started the left turn as instructed by the air traffic controller, the Cessna moved back toward the center of the HUD and then off to its right side, where it may have been obscured by the right structural post of the HUD. It was not visible again until about 2 seconds before the collision. (Figures 3a and 5a in the factual report for this accident show the simulated cockpit visibility from the F-16 at 1100:18 and 1100:56, respectively.) The F-16 pilot reported that before the controller alerted him to the presence of traffic, he was actively searching for traffic both visually and using the airplane's targeting radar. He reported that after the controller advised him of traffic, he was looking "aggressively" to find it. By the time he was able to visually acquire the Cessna, it was too late to avert the collision.

Our investigation could not determine to what extent the Cessna pilot was actively conducting a visual scan for other aircraft. Our aircraft performance and cockpit visibility study showed that the F-16 would have remained as a relatively small and slow-moving object out the Cessna's left window (between the Cessna's 9 and 10 o'clock positions) until less than 5 seconds before the collision. Given the speed of the F-16, the Cessna pilot likely would not have had adequate time to recognize and avoid the impending collision.

Cockpit Display of Traffic Information

Although the Cessna and F-16 pilots were responsible for seeing and avoiding each other, our aircraft performance and cockpit visibility study showed that, due to the physiological limitations of vision and the relative positions of the airplanes, both pilots would have had difficulty detecting the other airplane. Research indicates that any mechanism to augment and focus pilots' visual searches can enhance their ability to visually acquire traffic. (AC 90-48D highlights aircraft systems and technologies available to improve safety and aid in collision avoidance, and our report regarding a midair collision over the Hudson River [AAR-10/05] states that "traffic advisory systems can provide pilots with additional information to facilitate pilot efforts to maintain awareness of and visual contact with nearby aircraft to reduce the likelihood of a collision. …") One such method to focus a pilot's attention and visual scan is through the use of cockpit displays and aural alerts of potential traffic conflicts. Several technologies can provide this type of alerting by passively observing and/or actively querying traffic. While the accident airplanes were not equipped with these types of systems, their presence in one or both cockpits might have changed the outcome of the event. (The images from our in-cockpit traffic display simulation are representative of the minimum operations specifications contained in RTCA document DO-317B, Minimum Operational Performance Standards for Aircraft Surveillance Applications System [dated June 17, 2014], but do not duplicate the implementation or presentation of any particular operational display exactly; the actual images presented to a pilot depend on the range scale and background graphics selected by the pilot.)

Because the Cessna pilot was not in contact with ATC and was relying solely on the see-and-avoid concept, an indication of approaching traffic might have allowed him to visually acquire the F-16 and take action to avoid it. While most systems are limited to aiding pilots in their visual acquisition of a target and do not provide resolution advisories (specific maneuvering instructions intended to avoid the collision), the augmentation of a pilot's situational awareness might allow the pilot to change the flightpath in anticipation of a conflict and, thus, avoid airplanes coming in close proximity to one another. The Cessna pilot might have noted the presence of the F-16 and its level altitude of about 1,600 ft as he continued his departure climb. With this information, the Cessna pilot might have arrested his airplane's climb as he began a visual search, thus creating an additional vertical buffer between his airplane and the approaching F-16.

While the F-16 pilot's visual search was augmented by the controller's traffic advisory, a successful outcome would have depended upon the pilot's visual acquisition of the target airplane in time to take evasive action. Our in-cockpit traffic display simulation showed that the F-16 pilot might have first observed the Cessna when it was about 15 nm away, or nearly 3 minutes before the collision. As the F-16 closed to within 6 nm of the Cessna, or slightly more than 1 minute before the collision, the conflict might have become even more apparent to the pilot showing that not only were the airplanes in close proximity laterally but also that they were only separated vertically by 600 ft. As the F-16 pilot was beginning his left turn as instructed by ATC, the presence of the Cessna would have been aurally annunciated, and its traffic symbol would have changed from a cyan color to a yellow color. The information presented on the in-cockpit traffic display would have clearly indicated that the airplanes were on a collision course that might not be resolved by a left turn and that the vertical separation between the airplanes had decreased to 300 ft. 

Consequently, an in-cockpit traffic display could have helped the F-16 pilot recognize the potential for a collision in advance of the controller's instruction to turn left. The earlier warning also could have provided him additional time to conduct his visual search for the Cessna and potentially take other preemptive action to avoid the collision. Had the F-16 been equipped with a system that was able to provide the pilot with resolution advisories, the F-16 pilot could have taken action in response to that alarm to avoid the collision, even without acquiring the Cessna visually.

Postaccident Actions

In November 2016, we issued safety recommendations to the FAA and Midwest Air Traffic Control, Robinson Aviation, and Serco (companies that operate federal contract towers) to (1) brief all air traffic controllers and their supervisors on the ATC errors in this midair collision and one that occurred on August 16, 2015, near San Diego, California; and (2) include these midair collisions as examples in instructor-led initial and recurrent training for air traffic controllers on controller judgment, vigilance, and/or safety awareness.

In November 2016, we also issued a safety alert titled "Prevent Midair Collisions: Don't Depend on Vision Alone" to inform pilots of the benefits of using technologies that provide traffic displays or alerts in the cockpit to help separate safely. (In May 2015 [revised in December 2015], we issued a safety alert titled "See and Be Seen: Your Life Depends on It" regarding the importance of maintaining adequate visual lookout.)

After the accident, the Cessna's departure airport engaged in several outreach efforts (including posting midair collision avoidance materials locally and having outreach meetings with pilots) to raise awareness regarding midair collisions and encourage contact with ATC. The airport also updated its chart supplement to note the presence of military and other traffic arriving at and departing from CHS.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The approach controller's failure to provide an appropriate resolution to the conflict between the F-16 and the Cessna. Contributing to the accident were the inherent limitations of the see-and-avoid concept, resulting in both pilots' inability to take evasive action in time to avert the collision.

HISTORY OF FLIGHT

On July 7, 2015, about 1101 eastern daylight time, a Cessna 150M, N3601V, and a Lockheed Martin F-16CM, operated by the US Air Force (USAF), collided in midair near Moncks Corner, South Carolina. The private pilot and passenger aboard the Cessna died, and the Cessna was destroyed during the collision. The damaged F-16 continued to fly for about 2 1/2 minutes, during which the pilot activated the airplane's ejection system. The F-16 pilot landed safely using a parachute and incurred minor injuries, and the F-16 was destroyed after its subsequent collision with terrain and postimpact fire. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the Cessna, which departed from Berkeley County Airport (MKS), Moncks Corner, South Carolina, about 1057, and was destined for Grand Strand Airport, North Myrtle Beach, South Carolina. The personal flight was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The F-16 was operating on an instrument flight rules (IFR) flight plan and had departed from Shaw Air Force Base (SSC), Sumter, South Carolina, about 1020.

Air Force F-16

According to the USAF, the F-16 pilot was assigned as pilot-in-command for a single-ship, operational check flight to verify the completion of recent corrective maintenance. The flight itinerary included practice instrument approaches at Myrtle Beach International Airport (MYR), South Carolina, and Charleston Air Force Base/International Airport (CHS), Charleston, South Carolina, before returning to SSC. Since the flight was single ship and single pilot, the pilot performed an individual flight briefing using the personal briefing guide. (The Shaw General Briefing Guide is a local USAF document that F-16 pilots use to prepare for their missions.) Before departure, squadron personnel briefed the pilot on a range of subjects, including parking location, maintenance issues, aircraft configuration, notices to airmen, weather, and the mission timeline.

After departing from SSC, the F-16 proceeded to MYR, where the pilot conducted two practice instrument approaches before continuing to CHS. According to air traffic control (ATC) radar and voice communication data provided by the Federal Aviation Administration (FAA), the F-16 pilot contacted the approach controller at CHS about 1052 and requested to perform a practice tactical air navigation system (TACAN) instrument approach to runway 15. The controller instructed the F-16 pilot to fly a heading of 260º to intercept the final approach course. About 1055, the controller instructed the F-16 pilot to descend from 6,000 ft to 1,600 ft. About that time, the F-16 was located about 34 nautical miles (nm) northeast of CHS.

Cessna

Recorded airport surveillance video showed that the Cessna, which was based at MKS, departed from runway 23. At 1057:41, a radar target displaying a visual flight rules (VFR) transponder code of 1200, and later correlated to be the accident Cessna, appeared in the vicinity of the departure end of runway 23 at MKS at an indicated altitude of 200 ft. The Cessna continued its climb and began tracking generally southeast over the next 3 minutes. For the duration of the flight, the pilot of the Cessna did not contact any ATC facilities, nor was he required to do so.

The Collision

The CHS automated radar terminal system (ARTS IIE) detected a conflict between the F-16 and the Cessna at 1059:59. According to recorded radar data, the conflict alert (CA) was presented on the radar display and aurally alarmed at 1100:13, when the F-16 and the Cessna were separated laterally by 3.5 nm and vertically by 400 ft.

At 1100:16, the CHS approach controller issued a traffic advisory advising the F-16 pilot of "traffic 12 o'clock, 2 miles, opposite direction, 1,200 [ft altitude] indicated, type unknown." At 1100:24, the F-16 pilot responded that he was "looking" for the traffic. At 1100:26, the controller advised the F-16 pilot, "turn left heading 180 if you don't have that traffic in sight." At 1100:30, the pilot asked, "confirm 2 miles?" At 1100:33, the controller stated, "if you don't have that traffic in sight turn left heading 180 immediately." As the controller was stating the instruction and over the next 18 seconds, the radar-derived ground track of the F-16 began turning southerly toward the designated heading.

At 1100:49, the radar target of the F-16 was 1/2 nm northeast of the Cessna, at an altitude of 1,500 ft, and was on an approximate track of 215º. At that time, the Cessna reported an altitude of 1,400 ft and was established on an approximate ground track of 110º. At 1100:53, the controller advised the F-16 pilot, "traffic passing below you one thousand four hundred [ft]." At 1100:54, the altitude of the F-16 remained at 1,500 ft, and the last radar return was received from the Cessna. Recorded radar data indicated that the ARTS IIE continued to provide a CA to the controller until 1101:00. The next radar target for the F-16 was not received until 1101:13. At 1101:19, the F-16 pilot transmitted a distress call, and no subsequent intelligible transmissions were received.

Several witnesses observed both airplanes in the moments leading up to the collision. One witness, located adjacent to the west branch of the Cooper River, noticed the Cessna flying overhead, roughly from west to east, and then observed the F-16 flying overhead, roughly from north to south. He estimated that the two airplanes collided at an altitude of about 900 ft. He further described that both airplanes were "very low." The F-16 struck the left side of the Cessna, and debris began falling. He reported that a large black cloud of smoke appeared after the collision but did not observe any fire. He stated that neither airplane appeared to conduct any evasive maneuvers before the collision. After the collision, the F-16 then "powered up," turned right, and flew southbound along the river.

Another witness reported that he was standing in his backyard overlooking the river. He watched as the Cessna flew by from west to east. He next saw the F-16 flying toward the Cessna, coming from the Cessna's left rear position, roughly north to south. When the F-16 collided with the left side of the Cessna, debris started falling, with some landing in his yard. He stated that it looked as if the F-16 tried to "pull up" just before impact. After the impact, the F-16 turned right and flew along the river to the south and out of sight. Once the F-16 was out of sight, he heard several loud "bang" noises.

ATC radar continued to track the F-16 as it proceeded on a southerly course. After it descended to 300 ft, radar contact was lost at 1103:17 in the vicinity of the F-16 crash site. The F-16 pilot used the airplane's emergency escape system (ejection seat) to egress, incurring minor injuries as he landed on the ground under canopy. He was subsequently met by first responders. Figure 1 shows the calculated flight track for the F-16 and the Cessna.



PERSONNEL INFORMATION

F-16 Pilot

According to USAF personnel, the pilot of the F-16 was current and qualified in the accident airplane as a four-ship flight lead. His additional duties at the time of the accident included the position of 55th Fighter Squadron Chief of Mobility. At the time of the accident, he had accumulated 2,383 total hours of military flight experience, including 624 hours in the F-16. The pilot's total flight experience included 1,055 hours at the controls of the MQ-1B (Predator) and 456 hours at the controls of the MQ-9 (Reaper), both unmanned aerial vehicles. (The remaining hours were in USAF training aircraft and flight simulators.) His recent experience included 35 hours in the 90 days before the accident and 24 hours in the 30 days before the accident, all in the F-16. The USAF reported that the pilot was medically qualified for flight duty and was wearing contact lenses at the time of the accident.

The F-16 pilot's most recent instrument checkride was completed on August 25, 2014, and his most recent mission (tactical) checkride was completed on March 24, 2015. According to USAF records, none of the pilot's post-pilot training checkrides contained discrepancies or downgrades.

The F-16 pilot reported during a postaccident interview that he had accumulated about 50 hours of civilian flying experience and possessed an FAA-issued commercial pilot certificate obtained through 14 CFR 61.73. He had not flown civilian aircraft since he began initial USAF pilot training in July 2005.

Cessna Pilot

The pilot of the Cessna held a private pilot certificate with a rating for airplane single-engine land issued on December 29, 2014. His most recent, and only, FAA third-class medical certificate was issued on February 7, 2013, with no waivers or limitations. The pilot's personal flight logbook was recovered from the wreckage and contained detailed entries between May 2012 and July 5, 2015. As of the final entry, the pilot had accumulated 244 total flight hours, of which 239 hours were in the accident airplane make and model. He had flown 58 hours in the 90 days before the accident and 18 hours in the 30 days before the accident. Review of FAA records revealed no history of accidents, incidents, violations, or pending investigations.

The Cessna pilot's primary flight instructor indicated in a postaccident interview that the pilot was "very careful" and "responsive." He stated that the pilot "enjoyed" talking to ATC and was aware of the benefits. During his instruction, he would contact ATC for flight-following without being prompted. A review of the pilot's logbook revealed that he communicated with SSC ATC on at least 9 occasions and CHS ATC at least 21 times.

Air Traffic Controller

The CHS approach controller was hired by the FAA in August 2006 and attended the FAA academy in Oklahoma City before working at the Oakland Air Route Traffic Control Center. She resigned from the FAA in September 2007 and was rehired in February 2008. She worked at CHS since her rehire. Before working for the FAA, she served as an air traffic controller in the USAF from 1998 to 2000.

The controller was qualified and current on all operating positions at CHS and held no other FAA certifications. Her most recent FAA second-class medical certificate was issued on May 21, 2014, with a requirement to wear glasses while providing ATC services. She was wearing glasses on the day of the accident.

On the day of the accident, the controller was working a regularly scheduled 0700 to 1500 shift. At the time of the accident, she was working the radar west position combined with the radar east position, which was the normal radar configuration at CHS. The radar assistant position, called radar handoff, was also staffed. About 1101, when the accident occurred, she had been working the radar west position for about 1 1/2 hours.

AIRCRAFT INFORMATION

Cessna

The white- and red-colored Cessna 150M was a single-engine, high-wing airplane with a conventional tail. It was equipped with a rotating beacon light, anticollision strobe lights, navigation position lights, and a landing light. The operational status of each lighting system at the time of the accident could not be determined. Review of the airplane's maintenance and airworthiness records revealed no evidence that any supplemental equipment, such as high intensity anticollision lights, had been installed after delivery to enhance its visual conspicuity. The airplane was not equipped with a traffic advisory system (TAS), traffic alert and collision avoidance system (TCAS), or automatic dependent surveillance-broadcast (ADS-B) equipment or displays.

The Cessna was equipped with a King KX 155 single VHF communication radio, a King KT 78 mode C transponder, and an Ameri-King AK-350 altitude encoder. Review of maintenance records revealed that the most recent transponder and encoder tests per the requirements of 14 CFR 91.413 were completed on September 8, 2008. On July 20, 2012, an overhauled transponder and new altitude encoder of the same makes and models were installed. The units were ground tested in accordance with the procedures outlined in their respective maintenance manuals, but the maintenance records did not note any tests in accordance with 14 CFR 91.413. The pitot/static system was most recently tested per the requirements of 14 CFR 91.411 on April 11, 2013. The Cessna's most recent annual inspection was completed on October 14, 2014. At the time of the inspection, the airframe had accumulated 3,651 total hours of operation.

Air Force F-16

The gray-colored F-16 was a single-seat, turbofan-powered fighter airplane. Its most recent 400 hour phase inspection was completed on June 4, 2014, and it had accumulated 237 flight hours since that time. After a flight on June 11, 2015, USAF maintenance personnel completed work on the airplane's flight control system and subsequently cleared the airplane to return to service on July 2, 2015. At the time of the accident, the airframe had accumulated 4,435 total hours of operation. The airplane was not equipped with a TAS, TCAS, or ADS-B equipment or displays.

The USAF provided general information about the limitations of the F-16 radar and "identification friend or foe" (IFF) systems (more specific information is sensitive). The F-16 was equipped with a radar unit installed in the nose of the airplane that the pilot could use to locate and "lock on" to other aircraft. The radar was forward looking and limited to a search area spanning 120º directly in front of the F-16 (60º either side of center). The radar was also limited by the size of the target and was normally used to identify targets within a 40-mile range, but other settings were available. According to USAF personnel, the radar unit was designed to acquire fast moving enemy aircraft (not slow-moving, small aircraft). USAF personnel did not believe the radar would locate a small general aviation aircraft at takeoff or climb speed. The radar acquired targets by direct energy return off the target aircraft's surface and used aircraft closure rate rather than the airspeed of the other aircraft to filter out slow-moving targets.

When operating in search target acquisition mode, traffic was displayed as a small, white square target on the radar's multifunction displays (MFD), which were located on the cockpit instrument panel, near the pilot's knees. If a target existed, a subsequent sweep of the radar would reveal a new target, and the previous image would be lighter in intensity. There were no aural alerts if a new target appeared. The pilot could place a cursor over the target and "lock" the target on the radar if he/she chose. After locking on, the pilot could obtain the mean sea level (msl) altitude of the target.

The F-16 was also equipped with an IFF interrogator. Targets identified by this system would be displayed on the MFD, but it was not an integral part of the radar. The IFF interrogator could be programmed to request specific types of responses (1 to 4); most civilian aircraft with an operating ATC transponder would provide a "type 3" response. To receive any type of response, the F-16 pilot would have to manually initiate the interrogation process, which takes about 8 to 10 seconds to sweep and display all four types of responses, each being displayed for about 2 seconds.

The F-16 was equipped with a basic autopilot providing attitude hold, heading select, and steering select in the roll axis, and attitude hold and altitude hold in the pitch axis. There was no capability for autopilot-coupled instrument approaches. There were three bank settings: go-to heading, selected steer point, and hold bank angle. While the autopilot was engaged in heading select mode and a new heading was selected, the airplane would turn at about a bank angle not to exceed 30º. According to the F-16 flight manual, the autopilot was able to maintain altitude within ±100 ft under normal cruise conditions. Manual inputs through the control stick would override autopilot functions. If specific limits were exceeded during manual override, the autopilot would disconnect.

METEOROLOGICAL INFORMATION

The area forecast that included eastern South Carolina was issued at 0445 and forecasted scattered clouds between 3,000 and 4,000 ft msl, with scattered cirrus clouds and widely scattered light rain showers and thunderstorms after 1100.

The closest facility disseminating a terminal aerodrome forecast was CHS. The last forecast published before the accident was issued at 0723. The forecast weather conditions beginning at 0800 and continuing through 1300 included variable winds at 4 knots, greater than 6 statute miles visibility, and few clouds at 4,000 ft above ground level (agl).

Review of weather radar imagery showed no precipitation in the vicinity of the accident site about the time of the accident.

The weather conditions reported at MKS at 1055 included calm wind, 10 statute miles visibility, scattered clouds at 2,600 ft agl, a temperature of 30º C, a dew point of 22º C, and an altimeter setting of 30.15 inches of mercury.

The weather conditions reported at CHS at 1055 included wind from 220º true at 7 knots, 10 statute miles visibility, scattered clouds at 4,000 ft agl, a temperature of 30º C, a dew point of 22º C, and an altimeter setting of 30.15 inches of mercury.

At the time of the accident, the sun was about 57º above the horizon at an azimuth of about 99º.

AIRPORT INFORMATION

CHS has two intersecting runways oriented in a 15/33 and 03/21 configuration, at an elevation of 46 ft. The airport is served by numerous instrument approaches, including a VOR [very high omnidirectional range]/DME [distance measuring equipment] or TACAN approach to runway 15. The minimum altitude for the intermediate portion of the approach was 1,600 ft msl, while the minimum crossing altitude at the final approach fix, located 2.8 nm from the runway 15 threshold, was 1,100 ft msl.

ATC services at the airport are provided continuously by a combined ATC tower and terminal radar approach control (TRACON) facility. The CHS TRACON airspace extends for an approximate 40-nm radius from CHS, from the surface to 10,000 ft msl. Radar data are displayed to air traffic controllers at CHS via the ARTS IIE, with the radar feed from the airport surveillance radar (ASR-9), located at CHS.

The airport is surrounded by class C airspace, defined as that airspace extending from the surface up to and including 4,000 ft msl, within a 5-nm radius of CHS and that airspace extending from 1,200 ft msl up to and including 4,000 ft msl, within a 10-mile radius of CHS. There is no specific pilot certification required to operate within the class C airspace, but, according to 14 CFR 91.215, aircraft are required to be equipped with a two-way radio with an operable radar beacon transponder with automatic altitude reporting equipment. According to 14 CFR 91.130, before entering the class C airspace, two-way radio communication must be established and subsequently maintained with the ATC facility providing services.

Pilots requesting ATC services at CHS are required to contact the ATC facility on the publicized radio frequency and provide their position, altitude, radar beacon code, destination, and the nature of their request. Radio contact should be initiated far enough from the class C airspace boundary to preclude entering class C airspace before two-way radio communications are established. Beyond the class C airspace is an outer area that extends to a 20-nm radius of the airport. There were no specific communications or transponder requirements to operate in this area; however, approach control services could still be provided by ATC when operating in the outer area.

MKS, the Cessna's departure airport, is located about 17 nm north of CHS and is outside the CHS class C airspace. The airspace surrounding MKS and encompassing the collision location is designated as class E and extends from 700 ft agl to 17,999 ft msl. There are no two-way radio communication or transponder use requirements for operation in class E airspace. The established minimum vectoring altitude for ATC in this area is 1,600 ft, which represented the lowest altitude available to controllers when providing radar vectors to aircraft operating under IFR. Figure 2 shows an FAA sectional chart depicting CHS and class C airspace, MKS, and the approximate collision location. 



An instrument military training route (MTR), IR-18, transits generally south to north with an altitude structure of 5,000 to 7,000 ft msl, and is located about 1 nm east of MKS. A visual MTR, VR-1040/1041, transits generally east to west with an altitude structure of 200 to 1,500 ft agl and is located about 5 nm northwest of MKS. (The F-16 was not operating on either of these MTRs.) Several military operations areas, two USAF airbases, and a National Guard airbase are located within 60 nm of MKS. The airport/facility directory entry for MKS did not provide any warning or cautions regarding low altitude, high speed military air traffic in the vicinity of the airport.

FLIGHT RECORDERS

A crash-survivable memory unit (CSMU) was recovered from the wreckage of the F-16, and the digital flight control system seat data recorder was recovered from the airplane's ejection seat. Both memory units were forwarded to the airframe manufacturer for data extraction under the supervision of a National Transportation Safety Board (NTSB) vehicle recorder specialist. The data were downloaded normally with no anomalies noted.

WRECKAGE AND IMPACT INFORMATION

Cessna

The wreckage of the Cessna was recovered in the vicinity of its last observed radar target, over the west branch of the Cooper River. Components from both airplanes were spread over an area to the north and west of that point, extending for about 1,200 ft. The largest portions of the Cessna's airframe included a relatively intact portion of the fuselage aft of the main landing gear and the separate left and right wings, all of which were within 500 ft northwest of the airplane's final radar-observed position. Portions of the cabin interior, instrument panel, fuel system, and engine firewall were found distributed throughout the site. The engine, propeller, and nose landing gear assembly were not recovered. The lower aft engine cowling of the F-16 was also recovered in the immediate vicinity of the Cessna's aft fuselage, while the F-16's engine augmenter was recovered about 1,500 ft southwest. Small pieces of the F-16's airframe were also distributed throughout the accident site.

Both of the Cessna's wings displayed uniform leading-edge crush damage throughout their spans that was oriented aft and upward. Paint transfer and rub markings (consistent with paint from the F-16) oriented from left to right were observed along the upper forward surfaces of both wings. Both fuel tanks were ruptured, and evidence of heat damage and thermal paint blistering were observed on the upper surface of the right wing. Flight control continuity was traced through overload-type cable separations from the cabin area to each flight control surface. Measurement of the pitch trim actuator showed a position consistent with a 3º-to-4º deflection of the tab in the nose down direction, and measurement of the flap actuator showed a position consistent with the flaps having been in the retracted position.

Air Force F-16

The F-16 wreckage site was located about 6 nm south of the Cessna wreckage site. The F-16 wreckage path was about 700 ft long and oriented roughly 215º, with portions of the airframe distributed along the wreckage path. The wreckage displayed significant ground impact and postimpact fire-related damage.

MEDICAL AND PATHOLOGICAL INFORMATION

The Department of Pathology and Lab Medicine, Medical University of South Carolina, determined that the cause of death for both occupants of the Cessna was "blunt trauma." The FAA's Civil Aerospace Medical Institute performed postaccident toxicological testing on tissue specimens from the Cessna pilot. The specimens tested negative for a wide range of drugs, including major drugs of abuse. Although the specimens tested positive for ethanol, the levels of ethanol were consistent with postmortem ethanol production.

A Department of Defense Armed Forces medical examiner scientist performed postaccident toxicological testing on blood and urine specimens from the F-16 pilot, and the specimens tested negative for carbon monoxide, ethanol, and major drugs of abuse.

TESTS AND RESEARCH

Aircraft Performance and Cockpit Visibility Study

The NTSB's investigation examined the ability of the Cessna and F-16 pilots to see and avoid the other aircraft. To determine approximately how each aircraft would appear in the pilots' fields of view, the position of the "target" aircraft in a reference frame attached to the "viewing" aircraft must be calculated. This calculation depends on the positions and orientation (pitch, roll, and yaw angles) of each aircraft, as well as the location of the pilots' eyes relative to the cockpit windows. Data for the F-16 were derived from its CSMU, while orientation information for the Cessna was estimated based on an analysis of the radar data.

After the position and orientation of each airplane were determined, the position of each airplane in the body axis system of the other was calculated. These relative positions then determined where the "target" airplanes likely would have appeared in the fields of vision of the pilots of the "viewing" airplanes. The study assumed a nominal pilot seating (and eye) position in each cockpit and evaluated a matrix of eye displacements from the nominal eye position. For this study, the relative positions of the two airplanes were calculated beginning when the Cessna became visible on radar and then at 1-second intervals up to the collision. The time, location, and altitude of the collision were determined based on extrapolation of the radar and F-16 CSMU data and on the location of the main Cessna wreckage. The locations of the structures and transparencies of the F-16 and Cessna in the pilots' fields of view were determined from the interior and exterior dimensions of representative airplanes, as measured using a laser scanner. The structural obscurations to each pilot's view were merged with the calculated relative position data and are discussed below. The variations in eye position changed the timing of the obscurations of the opposite aircraft by less than +/-1.5 seconds at any given point.

At 1100:16, when the controller provided the initial traffic advisory to the F-16 pilot, the F-16 was in a wings-level attitude, at an altitude of about 1,570 ft, on a ground track of 252º, and at a ground speed of 253 knots. The Cessna's calculated position was 3.25 nm from the F-16, at a position directly ahead (about 12 o'clock), and at an altitude of roughly 1,200 ft. The Cessna's ground track was 109º, and it was climbing at a rate of about 240 ft per minute. The aircraft performance and cockpit visibility study showed that, at 1100:18, the Cessna would have appeared to the F-16 pilot as a very small, stationary object just above the horizon and near the center of the airplane's heads up display (HUD) (see figure 3a); the F-16 would have appeared to the Cessna pilot as a small, stationary object just above the horizon, but outside of the left cockpit door window, near the forward vertical post of the door frame (see figure 3b).




At 1100:26, when the controller advised the F-16 pilot, "turn left heading 180 if you don't have that traffic in sight," the relative positions changed slightly, with the Cessna moving slightly to the left but still remaining within the F-16's HUD, and the F-16 moving slightly aft in the Cessna pilot's left window.

At 1100:33, when the controller stated, "If you don't have that traffic in sight turn left heading 180 immediately" and as the F-16 began banking to the left, the F-16 pilot's view of the Cessna would have been obscured behind the left structural frame of the HUD. The position of the F-16 would have remained unchanged to the Cessna pilot.

At 1100:49, as the F-16 was executing its left turn at a bank angle of 30º, the Cessna would have become more discernable in the lower right portion of the F 16 pilot's HUD (see figure 4a). The F-16 would also have become more discernable, visible through the Cessna pilot's left window at a point just forward of the wing strut attachment point (see figure 4b).




At 1100:53, when the controller advised the F-16 pilot, "traffic passing below you" at 1,400 ft, the F-16 was flying at an altitude of 1,480 ft, while the estimated altitude of the Cessna was 1,440 ft. The closure rate of both airplanes at this point was 264 knots. The Cessna would have been visible to the right of the structural frame of the F 16's HUD, while the F-16 would have appeared to the Cessna pilot in largely the same position but with a more defined shape.

Over the next 3 seconds, the airplanes continued to approach each other, with the F-16 approaching the Cessna from its left and slightly above. The Cessna would have been completely obscured by the lower right cockpit structure of the F-16, as the airplane banked in its turn to the left (see figure 5a). The F 16 would have become partially obscured by the left wing strut (see figure 5b).



In-Cockpit Traffic Display Simulation

The FAA's Aeronautical Information Manual (AIM) (dated December 10, 2015, and revised on May 26, 2016), paragraph 4-5-7, states that ADS B is a surveillance technology deployed throughout the National Airspace System. The ADS-B system is composed of aircraft avionics and a ground infrastructure. Onboard avionics determine the position of an aircraft by using the GPS and transmitting its position along with additional information about the aircraft to ground stations for use by ATC and other ADS-B services. This information is transmitted at a rate of approximately once per second. ADS-B avionics can have the ability to both transmit and receive information. The transmission of ADS-B information from an aircraft is known as ADS B Out. The receipt of ADS-B information by an aircraft is known as ADS-B In. On January 1, 2020, all aircraft operating within the airspace defined in 14 CFR 91.225 will be required to transmit the information defined in 14 CFR 91.227 using ADS-B Out avionics.

The ADS-B capabilities that enhance a pilot's awareness of airborne traffic in their vicinity are described in FAA Advisory Circular (AC) 20-172B, "Airworthiness Approval for ADS-B In Systems and Applications." Per the AC, this capability allows an appropriately equipped aircraft to receive and display another aircraft's ADS-B Out information, as well as ground station broadcast information, from services like traffic information services-broadcast (TIS-B) and automatic dependent surveillance-rebroadcast (ADS-R). The received information is processed by onboard avionics and presented to the flight crew on a display. ADS-B In avionics enable a number of aircraft surveillance applications and can enhance visual acquisition by displaying nearby traffic on a plan view (bird's eye view) relative to own-ship. The traffic information assists pilots in visually acquiring traffic out the window while airborne but does not relieve them of see-and-avoid responsibilities. Additionally, the information derived through ADS-B In applications can be used to provide voice annunciations to flight crews to draw attention to alerted traffic.

The images from the NTSB's in-cockpit traffic display simulation presented in figures 6 and 7 are representative of the minimum operations specifications for such displays contained in RTCA document DO-317B but do not duplicate the implementation or presentation of any particular operational display exactly. The actual images presented to a pilot depend on the range scale and background graphics selected by the pilot (which could reflect various implementations and combinations of moving maps, terrain elevation data, and weather information, rather than the simple black background presented here).

For this accident, simulated in-cockpit displays of traffic information for both the F-16 and Cessna were created based on the TIS-B information that would have been displayed to the pilot of each airplane assuming that both aircraft were equipped with ADS-B In capability and avionics capable of displaying and aurally annunciating the traffic information. In addition, the simulation assumes that at least one ADS-B Out equipped aircraft was operating in the vicinity of the two accident aircraft in order to trigger the broadcast of TIS-B information from a ground station, as currently, aircraft equipped with only ADS-B In cannot trigger the broadcast of this information.

The NTSB's in-cockpit traffic display simulation for the F-16 indicates that at 1058:06, an open (outlined), cyan-colored, arrowhead-shaped target representing the Cessna would have appeared at the F 16's 12 o'clock position (straight ahead), 15 nm from and 1,300 ft below the F-16. The Cessna would have been the only target within that range from that time up to the time of the collision at 1100:57. As the airplanes approached each other, the Cessna target would have been shown turning left from west to east and then approaching the F-16 from its 12 o'clock position, slightly to the right of the F-16's flightpath, and climbing. The heading depicted by the Cessna symbol as the aircraft converged would have indicated that the Cessna's projected flightpath would cross the F-16's flightpath from right to left. At 1059:47, the Cessna symbol would have changed from an open cyan arrowhead to a filled cyan arrowhead, as the Cessna closed within 6 nm horizontally and 600 ft vertically of the F-16.

At 1100:35, as the F-16 banked into its left turn toward the south, the pilot would have received an aural alert associated with the Cessna, which by then had closed within 2 nm horizontally and 300 ft vertically. The aural alert would have advised, "Traffic, 12 o'clock, low, 2 miles." As shown in figure 6, the Cessna symbol would have changed to a filled yellow arrowhead, enclosed by a yellow circle. As the F-16 continued in its left turn, the Cessna target would have rotated to the right side of the F-16's projected course, with its heading still projected to intercept that course. At 1100:56, one second before the collision, the F-16 would have received a second aural alert of "Traffic, 2 o'clock, same altitude, zero miles." The symbol representing the Cessna would have depicted it 100 ft below the F-16 (see figure 6).



The in-cockpit traffic display simulation for the Cessna indicates that at 1058:05, an open cyan target representing the F-16 would have appeared at the Cessna's 8 o'clock position, 15 nm from and 1,300 ft above the Cessna. The F-16 would have been one of two targets within that range from that time up to the time of the collision at 1100:57. The other target would have appeared between the Cessna's 12 and 1 o'clock position, about 11 nm from and 1,300 ft above the Cessna. As the Cessna turned left toward the east, the F-16 target would have rotated to the Cessna's 11 o'clock position and been depicted flying toward the Cessna. The other aircraft would have rotated to the Cessna's 3 o'clock position and been depicted flying away from the Cessna. At 1059:47, the F-16 symbol would have changed from an open cyan arrowhead to a filled cyan arrowhead, as the F-16 closed within 6 nm horizontally and 600 ft vertically of the Cessna.

At 1100:35, as the F-16 banked into its left turn toward the south, the Cessna pilot would have received an aural alert associated with the F-16, which by then had closed within 2 nm horizontally and 300 ft vertically. The aural alert would have advised, "Traffic, 11 o'clock, high, 1 mile." As shown in figure 7, the F-16 symbol would have changed to a filled yellow arrowhead, enclosed by a yellow circle. The Cessna would not have received a second aural alert for the F-16, but the F-16 symbol would have remained in alert status (filled yellow arrowhead enclosed by a yellow circle) until the collision.



ORGANIZATIONAL AND MANAGEMENT INFORMATION

USAF Mid-Air Collision Avoidance Program

The USAF has a Mid-Air Collision Avoidance (MACA) program detailed in Air Force Instruction (AFI) 91-202, dated June 24, 2015. According to AFI 91-202, USAF flying units must have a written MACA program, and the unit safety office is responsible for its creation, documentation, and upkeep. The 20th Fighter Wing (FW) Safety Office administered the Shaw Air Force Base MACA program. The required elements are a MACA pamphlet and a poster, primarily designed for use in the civilian community. The program includes civilian outreach and incorporates interaction with pilot advocacy organizations, the FAA, local airports, and fixed base operators. The 20th FW Safety Office also maintains a public website populated with the MACA program products and other safety information. According to 20th FW Safety Office personnel, activities related to MACA are coordinated with two other military bases: Charleston Joint Base and McEntire Joint National Guard Base. The Charleston Joint Base Flight Safety office held MACA seminars at MKS in June 2012, January 2014, and March 2015.

ADDITIONAL INFORMATION

Postaccident Interviews

F-16 Pilot

Members of the USAF Accident Investigation Board interviewed the F-16 pilot after the accident. He reported that he had the radar configured for a 20- and 40-mile range, manually alternating back and forth, and could not recall if his IFF interrogator was set up to receive civilian transponder replies. He was using a scan pattern that included looking outside; checking instruments for altitude, airspeed, and heading; and checking the radar display.

The F-16 pilot indicated that he had acquired and locked on a radar target 20 miles away. He stated that shortly thereafter, the controller issued an alert for traffic at his 12 o'clock position, 2 miles away, at 1,200 ft. He remarked that a 2-mile call was the "…closest call I've ever received" and that it was "…a big alert for me." He then asked the controller to "confirm two miles"; he indicated in a postaccident interview that he asked that question because he was looking at traffic on his radar at 20 miles away. He then began aggressively looking to visually acquire the airplane and recalled a command from the controller to turn left "immediately" to a heading of 180º. He stated that he used the autopilot to execute the turn so that he could continue to search outside for the traffic. The autopilot turn used 30º of bank and standard rate, or 3º per second of turn. He continued to search for the traffic until he observed the Cessna directly in front of his airplane, "within 500 feet." He then applied full aft control stick inputs to avoid a collision, but it was "too late." He estimated that the time from initial sighting of the Cessna to the impact was less than 1 second. After the collision, he attempted to maintain control of his airplane; however, once he determined that continued controlled flight was not possible, he initiated his emergency egress.

Air Traffic Controller

The air traffic controller described the traffic on the day of the accident as light and routine, with nothing out of the ordinary. Several USAF fighter aircraft from SSC were making approaches to CHS when the F-16 entered the airspace from the northeast and requested a TACAN approach. The controller told the pilot to expect the requested approach and provided climb-out instructions after completing the approach. She issued a radar vector of 260º to intercept the 10- to 15-mile final approach course for the instrument approach. The intent of this vector was to keep the F-16 south of, and to avoid overflying, MKS. The controller stated that she then directed the F-16 to descend and maintain 1,600 ft and was "pretty much done with him" while she worked other traffic, including a flight of two other F 16s. She had descended the accident airplane to 1,600 ft because that was the minimum vectoring altitude at CHS. She stated that this was her usual technique; getting aircraft to their final altitude quickly allowed her more efficient use of her time.

When the controller initially noticed the Cessna depart from MKS, she thought that it would remain in the local VFR traffic pattern. She described that, generally, pattern traffic at MKS was rare and, when present, typically stayed below 1,000 ft. She then descended the other two aircraft flight of F-16s to sequence them behind the accident F-16 and to get them around other traffic. Shortly after, she asked the two-aircraft flight to expedite its descent to 3,000 ft and noticed that the Cessna was climbing above 1,000 ft. She responded by advising the F-16 pilot, hoping that he would be able to visually acquire the traffic, but the F-16 pilot did not report the traffic in sight. She advised the F-16 pilot to turn left heading 180 if he did not have the traffic in sight.

As the radar targets were continuing to close on one another, she directed the F-16 pilot that if he did not have the traffic in sight to turn left heading 180 immediately. She reported that the 180 heading assignment was preferred over a turn to the north because the turn was quicker, and she believed that "fighters could turn on a dime." She stated that her expectation was that the word "immediately" meant to react now and that, with a fighter aircraft, it meant to do a "max performance turn" to the heading. She stated that she did not recall seeing or hearing a CA generated by the ATC radar system. The controller indicated in a postaccident interview that she chose not to direct the F 16 to climb because the altitude indicated for the Cessna's radar target was unconfirmed.

The controller advised the F-16 pilot that the Cessna had passed below him and thought the two aircraft were clear of each other until she saw the Cessna's radar target disappear followed by the F 16 pilot's distress call. She briefly initiated a call to the pilot and then turned to the radar handoff controller and told him "I don't know what to do." The radar handoff controller advised her to "separate what you've got."

ATC Radar Equipment

The radar display system in use at CHS at the time of this accident, ARTS IIE, is designed to support one or two sensors and up to 22 displays in two different configurations and can process 256 simultaneous tracks per sensor. At the time of the accident, there were no known or reported equipment discrepancies with the ARTS IIE system that would have affected the controller's ability to provide ATC services.

The ARTS IIE has numerous capabilities and functions to help controllers with strategic and tactical decision-making. One of these functions is the CA/mode C intruder, which provides controllers with visual and immutable aural warnings for aircraft that are or will be in dangerous proximity to one another. A CA provides a visual presentation on the radar scope display associated with the conflicting aircraft and an aural alarm when conditions warrant. These conditions are based on vertical and horizontal parameters established for the environment in which the aircraft are operating. For example, in an en route environment where aircraft are operating at higher altitudes and faster speeds, the parameters would be more sensitive when compared to an airport environment, where aircraft operate closer to each other and at lower speeds. For a predicted alert, the ARTS IIE evaluates a developing conflict for two of three consecutive radar sweeps. The average sweep of an ASR (a 360º scan) takes about 5 seconds.

The CHS ARTS IIE detected the conflict between the F-16 and the Cessna at 1059:59, and the CA was presented on the radar scope with an accompanying aural alert at 1100:13. The ARTS IIE continued to provide a CA to the controller until 1101:00. As the controller stated in her postaccident interview, she did not recall seeing or hearing the CA, but review of archived ATC audio revealed that her initial traffic advisory to the F-16 began at 1100:16, 3 seconds after the CA alerted. A postaccident test of the CA alarm at CHS revealed that it worked properly.

FAA and USAF Rules, Regulations, and Guidance to Pilots

Title 14 CFR 91.113 addresses aircraft right-of-way rules and states, in part, the following:

(b) General. When weather conditions permit, regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft.

The FAA's AIM, dated April 3, 2014, paragraph 5-5-8, includes pilot procedures for see-and-avoid while in flight and states, "When meteorological conditions permit, regardless of type of flight plan or whether or not under control of a radar facility, the pilot is responsible to see and avoid other traffic, terrain, or obstacles."

The AIM, paragraph 4-1-9, also describes operations to/from airports without an operating control tower and the use of a common traffic advisory frequency (CTAF) and states, in part, the following:

a. Airport Operations Without Operating Control Tower

1. There is no substitute for alertness while in the vicinity of an airport. It is essential that pilots be alert and look for other traffic and exchange traffic information when approaching or departing an airport without an operating control tower…To achieve the greatest degree of safety, it is essential that all radio-equipped aircraft transmit/receive on a common frequency identified for the purpose of airport advisories.

b. Communicating on a Common Frequency

The key to communicating at an airport without an operating control tower is selection of the correct common frequency…A CTAF is a frequency designated for the purpose of carrying out airport advisory practices while operating to or from an airport without an operating control tower.

The AIM describes the recommended communication procedures regarding departure aircraft on the CTAF and states, "Pilots of inbound traffic should monitor and communicate as appropriate on the designated CTAF from 10 miles to landing. Pilots of departing aircraft should monitor/communicate on the appropriate frequency from start-up, during taxi, and until 10 miles from the airport unless the CFRs or local procedures require otherwise."

The AIM, paragraph 5-5-10, describes the manner in which pilots could expect to receive traffic advisories from ATC and states the following:

a. Pilot.
1. Acknowledges receipt of traffic advisories.
2. Informs controller if traffic in sight.
3. Advises ATC if a vector to avoid traffic is desired.
4. Does not expect to receive radar traffic advisories on all traffic. Some aircraft may not appear on the radar display. Be aware that the controller may be occupied with higher priority duties and unable to issue traffic information for a variety of reasons.
5. Advises controller if service is not desired.

b. Controller.
1. Issues radar traffic to the maximum extent consistent with higher priority duties except in Class A airspace.
2. Provides vectors to assist aircraft to avoid observed traffic when requested by the pilot.
3. Issues traffic information to aircraft in the Class B, Class C, and Class D surface areas for sequencing purposes.
4. Controllers are required to issue to each aircraft operating on intersecting or nonintersecting converging runways where projected flight paths will cross.

The Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-24A), section 13, addresses scanning procedures for visually acquiring traffic:

The pilot can contribute to collision avoidance by being alert and scanning for other aircraft. This is particularly important in the vicinity of an airport.

Effective scanning is accomplished with a series of short, regularly spaced eye movements that bring successive areas of the sky into the central visual field. Each movement should not exceed 10º, and each should be observed for at least 1 second to enable detection. Although back and forth eye movements seem preferred by most pilots, each pilot should develop a scanning pattern that is most comfortable and then adhere to it to assure optimum scanning. Even if entitled to the right-of-way, a pilot should yield if another aircraft seems too close.

(The most recent version of this handbook, FAA-H-8083-25B, was published in 2016.)

The AIM Pilot-Controller Glossary defines "immediately" as a term used by ATC or pilots when such action compliance was required to avoid an "imminent situation."

The AIM, paragraph 4-4-10, states, in part, the following about adherence to clearance:

a. When air traffic clearance has been obtained under either visual or instrument flight rules, the pilot-in-command of the aircraft must not deviate from the provisions thereof unless an amended clearance is obtained. When ATC issues a clearance or instruction, pilots are expected to execute its provisions upon receipt. ATC, in certain situations, will include the word "IMMEDIATELY" in a clearance or instruction to impress urgency of an imminent situation and expeditious compliance by the pilot is expected and necessary for safety...

b. When a heading is assigned or a turn is requested by ATC, pilots are expected to promptly initiate the turn, to complete the turn, and maintain the new heading unless issued additional instructions.

Air Force Manual 11-248, dated January 19, 2011, T-6 Primary Flying, addresses clearing procedures in section 1.16:

1.16. Clearing. Each crewmember is responsible for collision avoidance - regardless of rank, experience, or cockpit position - whether instrument flight rules (IFR) or VFR….Pilots have the responsibility to clear the aircraft in all directions, and although the use of radar monitoring, assigned areas, or ATC separation can assist in ensuring clearance, it does not relieve pilots of the responsibility. The following principles apply to clearing regardless of flight conditions:

1.16.1. Visual detection is the most important factor in clearing for other aircraft.

FAA Guidance to Air Traffic Controllers

FAA Order 7110.65, Air Traffic Control, prescribes ATC procedures and phraseology for use by personnel providing ATC services. Paragraph 2-1-2, "Duty Priority," states, in part, that controllers should "give first priority to separating aircraft and issuing safety alerts as required in this order. Good judgment must be used in prioritizing all other provisions of this order based on the requirements of the situation at hand."

Paragraph 2-1-5, "Expeditious Compliance," states, in part, that controllers should "use the word 'immediately' only when expeditious compliance is required to avoid an imminent situation."

Paragraph 2-1-6, "Safety Alerts," states, in part, the following:

Issue a safety alert to an aircraft if you are aware the aircraft is in a position/altitude that, in your judgment, places it in unsafe proximity to terrain, obstructions, or other aircraft….

Note-
1. The issuance of a safety alert is a first priority…once the controller observes and recognizes a situation of unsafe aircraft proximity to terrain, obstacles, or other aircraft. Conditions, such as workload, traffic volume, the quality/limitations of the radar system, and the available lead time to react are factors in determining whether it is reasonable for the controller to observe and recognize such situations. While a controller cannot see immediately the development of every situation where a safety alert must be issued, the controller must remain vigilant for such situations and issue a safety alert when the situation is recognized….

b. Aircraft Conflict/Mode C Intruder Alert. Immediately issue/initiate an alert to an aircraft if you are aware of another aircraft at an altitude that you believe places them in unsafe proximity. If feasible, offer the pilot an alternate course of action. When an alternate course of action is given, end the transmission with the word "immediately."

Phraseology—
Traffic alert (call sign) (position of aircraft) advise
You turn left/right (heading),

and/or

Climb/descend (specific altitude if appropriate)
immediately.

Paragraph 2-1-21, "Traffic Advisories," states the following:

Unless an aircraft is operating within Class A airspace or omission is requested by the pilot, issue traffic advisories to all aircraft (IFR or VFR) on your frequency when, in your judgment, their proximity may diminish to less than the applicable separation minima. Where no separation minima applies, such as for VFR aircraft outside of Class B/Class C airspace, or a TRSA [terminal radar service area], issue traffic advisories to those aircraft on your frequency when in your judgment their proximity warrants it. Provide this service as follows:

a. To radar identified aircraft:

1. Azimuth from aircraft in terms of the 12-hour clock, or
2. When rapidly maneuvering aircraft prevent accurate issuance of traffic as in 1 above, specify the direction from an aircraft's position in terms of the eight cardinal compass points (N, NE, E, SE, S, SW, W, and NW). This method must be terminated at the pilot's request.
3. Distance from aircraft in miles.
4. Direction in which traffic is proceeding and/or relative movement of traffic.
Note-
Relative movement includes closing, converging, parallel same direction, opposite direction, diverging, overtaking, crossing left to right, crossing right to left.
5. If known, type of aircraft and altitude.
Phraseology-Traffic, (number) o'clock, or when appropriate,

(direction) (number) miles, (direction)-bound and/or (relative movement),

and if known,

(type of aircraft and altitude).

or

When appropriate,

(type of aircraft and relative position), (number of feet) feet above/below you.

If altitude is unknown,

Altitude Unknown.

Example-
"Traffic, eleven o'clock, one zero miles, southbound, converging, Boeing Seven Twenty Seven, one seven thousand."
"Traffic, twelve o'clock, one five miles, opposite direction, altitude unknown."
"Traffic, ten o'clock, one two miles, southeast bound, one thousand feet below you."
6. When requested by the pilot, issue radar vectors to assist in avoiding the traffic, provided the aircraft to be vectored is within your area of jurisdiction or coordination has been effected with the sector/facility in whose area the aircraft is operating.
7. If unable to provide vector service, inform the pilot.
8. Inform the pilot of the following when traffic you have issued is not reported in sight:
(a) The traffic is no factor.
(b) The traffic is no longer depicted on radar.
Phraseology-

Traffic no factor/no longer observed, 

or

(number) o'clock traffic no factor/no longer observed, 

or

(direction) traffic no factor/no longer observed. 

b. To aircraft that are not radar identified:
1. Distance and direction from fix.
2. Direction in which traffic is proceeding.
3. If known, type of aircraft and altitude.
4. ETA over the fix the aircraft is approaching, if appropriate.
Phraseology-
Traffic, (number) miles/minutes (direction) of (airport or fix), (direction)-bound,

and if known,

(type of aircraft and altitude),

estimated (fix) (time),

or

Traffic, numerous aircraft vicinity (location).

If altitude is unknown,

Altitude Unknown.

Example-
"Traffic, one zero miles east of Forsythe V-O-R, Southbound, M-D Eighty, descending to one six thousand."
"Traffic, reported one zero miles west of Downey V-O-R, northbound, Apache, altitude unknown, estimated Joliet V-O-R one three one five."
"Traffic, eight minutes west of Chicago Heights V-O-R, westbound, Mooney, eight thousand, estimated Joliet V-O-R two zero three five."
"Traffic, numerous aircraft, vicinity of Delia airport."

c. For aircraft displaying Mode C, not radar identified, issue indicated altitude.
Example-
"Traffic, one o'clock, six miles, eastbound, altitude indicates six thousand five hundred."

The See-and-Avoid Concept

The FAA issued AC 90-48C, "Pilots' Role in Collision Avoidance," in 1983 to alert all pilots "…to the potential hazards of midair collisions and near midair collision [NMAC], and to emphasize those basic problem areas related to the human causal factors where improvements in pilot education, operating practices, procedures, and improved scanning techniques are needed to reduce midair conflicts." (This version of the AC was in place at the time of the accident; an updated version, AC 90-48D, was issued in April 2016 and is discussed further below.)

AC 90-48C stated that each person operating an aircraft, regardless of whether the operation was conducted under IFR or VFR, shall maintain a vigilant lookout for other aircraft at all times. Regarding visual scanning, the AC specifically stated that "Pilots should remain constantly alert to all traffic movement within their field of vision, as well as periodically scanning the entire visual field outside of their aircraft to ensure detection of conflicting traffic" (emphasis in the original). AC 90-48C also described several specific methods that pilots could use to visually acquire other traffic.

AC 90-48C also discussed the use of ATC services:

One of the major factors contributing to the likelihood of NMAC incidents in terminal areas that have an operating air traffic control (ATC) system has been the mix of known arriving and departing aircraft with unknown traffic. The known aircraft are generally in radio contact with the controlling facility (local, approach, or departure control) and the other aircraft are neither in two-way radio contact nor identified by ATC at the time of the NMAC. (emphasis in the original)

The AC recommended that pilots use ATC traffic advisory services but stressed that those services do not lessen the pilot's obligation to see and avoid other traffic.

Finally, the AC provided data on the time required for a pilot to recognize an approaching aircraft and execute an evasive maneuver. The total time to identify an approaching aircraft, recognize a collision course, decide on action, execute the control movement, and allow the aircraft to respond was estimated to be around 12.5 seconds.

In 1991, the Australian Transport Safety Bureau (ATSB) published a research report titled Limitations of the See-and-Avoid Principle. The report discusses the role of the see-and-avoid concept in preventing collisions and some of its inherent limitations:

Cockpit workload and other factors reduce the time that pilots spend in traffic scans. However, even when pilots are looking out, there is no guarantee that other aircraft will be sighted. Most cockpit windscreen configurations severely limit the view available to the pilot. The available view is frequently interrupted by obstructions such as window-posts which totally obscure some parts of the view and make other areas visible to only one eye....Visual scanning involves moving the eyes in order to bring successive areas of the visual field onto the small area of sharp vision in the centre of the eye. The process is frequently unsystematic and may leave large areas of the field of view unsearched….The physical limitations of the human eye are such that even the most careful search does not guarantee that traffic will be sighted….An object which is smaller than the eye's acuity threshold is unlikely to be detected and even less likely to be identified as an approaching aircraft….The human visual system is better at detecting moving targets than stationary targets, yet in most cases, an aircraft on a collision course appears as a stationary target in the pilot's visual field. The contrast between an aircraft and its background can be significantly reduced by atmospheric effects, even in conditions of good visibility. An approaching aircraft, in many cases, presents a very small visual angle until a short time before impact. In addition, complex backgrounds such as ground features or clouds hamper the identification of aircraft via a visual effect known as 'contour interaction'. This occurs when background contours interact with the form of the aircraft, producing a less distinct image. Even when an approaching aircraft has been sighted, there is no guarantee that evasive action will be successful.

The ATSB report also discusses the value of alerted versus unalerted searches for traffic:

A traffic search in the absence of traffic information is less likely to be successful than a search where traffic information has been provided because knowing where to look greatly increases the chance of sighting the traffic (Edwards and Harris 1972). Field trials conducted by John Andrews found that in the absence of a traffic alert, the probability of a pilot sighting a threat aircraft is generally low until a short time before impact. Traffic alerts were found to increase search effectiveness by a factor of eight. A traffic alert from ATS or from a radio listening watch is likely to be similarly effective (Andrews 1977, Andrews 1984, Andrews 1987).

The ATSB report concludes, in part, that "The see-and-avoid principle in the absence of traffic alerts is subject to serious limitations….Unalerted see-and-avoid has a limited place as a last resort means of traffic separation at low closing speeds but is not sufficiently reliable to warrant a greater role in the air traffic system."

Cockpit Display of Traffic Information

In April 2016, the FAA published an update to "Pilots' Role in Collision Avoidance" (AC 90 48D), which highlights aircraft systems and technologies available to improve safety and aid in collision avoidance. Among those technologies, the recommended safety equipment includes TAS, TCAS (I and II), and ADS-B with display capability. The updated AC also discusses the information provided by each of these systems and stresses that they are intended as a supplement to, and not replacement for, the visual acquisition and avoidance of other aircraft.

Regarding the use of ADS-B as a tool to aid in a pilot's situational awareness, the AC states, in part, the following:

ADS-B is a system for air traffic surveillance. The FAA has mandated ADS-B Out by 2020 on all aircraft operating in current Mode C airspace (around Class B and C airspace and above 10,000 feet). With ADS-B, each aircraft broadcasts its own Global Positioning System (GPS) position along with other information like heading, ground track, groundspeed, and altitude (ADS-B Out). To see other aircraft, you must be equipped with ADS-B In to process the data signals.

The AC describes how other systems that actively interrogate other aircraft would continue to be useful beyond the FAA-mandated ADS-B Out requirement in 2020:

Active Traffic Systems. Active traffic systems (including TAS and TCAS) use Mode A, C, or S transponder interrogations to determine aircraft bearing and distance. Altitude is determined by reported Mode C altitude. After 2020, aircraft will be required to broadcast ADS-B Out and this data can be interpreted by aircraft with ADS-B In, but aircraft will still be required to have a Mode C or S transponder in airspace where it is currently required; thus, active traffic systems will continue to function. Most TAS systems will have ADS-B In capability available as an upgrade so these systems can interpret signals from either source.

Active Traffic Systems in an ADS-B Environment. Active traffic systems are valuable for three reasons in an ADS-B environment. First, even after January 1, 2020, not all aircraft will have ADS-B Out, particularly in airspace which does not require it. Thus, without an active traffic system, those unequipped aircraft would not display on a cockpit traffic display even if you had ADS-B In. Second, an active traffic system will display all aircraft independent of the type of ADS-B Out, since all aircraft will still be required to have a Mode C or Mode S transponder. Third, ADS-B is dependent on GPS signals, so during periods of poor satellite geometry or solar storms, GPS position and thus ADS-B could be disrupted and less reliable, meaning an active traffic system can act as a backup to ADS-B in the cockpit.

In 1977, the Massachusetts Institute of Technology published a report for the FAA, titled Air to Air Visual Acquisition Performance with Pilot Warning Instruments (PWI), which describes how PWI could be used to aid pilots in the visual acquisition task. These instruments would generally use some electronic means to detect and then present pilots with information about particular threats, focusing their attention to where it was most needed:

The primary intent of PWI is to improve the search performance of the pilot. The PWI alarm ensures that scanning will be given high priority when it is most critical and by directing the pilot's search to a particular sector, the area to be scanned is greatly reduced. Another effect discovered in the IPC [Intermittent Positive Control]/PWI flight tests is the tendency of PWI to reduce the effect of airframe obstruction. Not only do pilots shift their positions within the cockpit in an effort to scan a threat sector, but many pilots alter the aircraft attitude in order to achieve an unobstructed view in the threat direction. Thus, PWI favorably affects the first two elements of acquisition (search and field of view). It does not alter detectability or speed of approach in any direct way.

Research into pilots' performance in the visual acquisition task conducted in support of the report found that "Unaided visual acquisition is effective as a means of separation assurance only for lower values of crossing angles (relative heading). At higher values of crossing angle the increased closure speeds and decreased visible areas reduce performance considerably."

In our report regarding a midair collision over the Hudson River (Midair Collision Over Hudson River, Piper PA-32R-300, N71MC, and Eurocopter AS350BA, N401LH, Near Hoboken, New Jersey, August 8, 2009, AAR-10/05), the NTSB stated, in part, the following;

There are inherent limitations associated with the see-and-avoid concept as the primary method for aircraft separation. These limitations include a pilot's ability to perform systematic scans, competing operational task demands, environmental factors, and blind spots associated with an aircraft's structure. Traffic advisory systems can provide pilots with additional information to facilitate pilot efforts to maintain awareness of and visual contact with nearby aircraft to reduce the likelihood of a collision.

Most traffic advisory systems, including TIS [traffic information service], have visual displays of nearby traffic that show an aircraft's position or distance, direction of travel, and relative altitude and indicate whether the aircraft is climbing or descending. The NTSB recognizes that incorporating a visual traffic display into a pilot's scan could increase workload, but any increase in workload would be offset by the safety benefits resulting from the augmented awareness of other aircraft operating in the area, as displayed by the traffic system. However, these safety benefits are not a substitute for the see-and-avoid concept. In fact, Garmin guidance stated that TIS does not relieve pilots of their responsibility to see and avoid other aircraft. Thus, pilots are responsible for paying attention to the position of other aircraft for collision avoidance and not relying solely on a traffic advisory system for aircraft position information.

National Transportation Safety Board - Aviation Accident Final Report: http://app.ntsb.gov/pdf 

National Transportation Safety Board  -   Docket And Docket Items: http://dms.ntsb.gov/pubdms

National Transportation Safety Board  -  Aviation Accident Data Summary:   http://app.ntsb.gov/pdf

NTSB Identification: ERA15MA259A
14 CFR Part 91: General Aviation
Accident occurred Tuesday, July 07, 2015 in Moncks Corner, SC
Probable Cause Approval Date: 11/15/2016
Aircraft: CESSNA 150M, registration: N3601V
Injuries: 2 Fatal, 1 Minor.

NTSB investigators traveled in support of this investigation and used data obtained from various sources to prepare this aircraft accident report.

The pilot of the F-16, who was operating on an instrument flight rules (IFR) flight plan, was in contact with air traffic control (ATC) and was provided radar vectors for a practice instrument approach to Charleston Air Force Base/International Airport (CHS), Charleston, South Carolina; the F-16 descended to an altitude of about 1,600 ft mean sea level as instructed by the air traffic controller. Shortly thereafter, the Cessna departed under visual flight rules (VFR) from a nearby nontowered airport; the Cessna pilot was not in contact with ATC, nor was he required to be, and had not requested traffic advisory (flight-following) services. As the Cessna continued its departure climb, the airplanes converged to within about 3.5 nautical miles (nm) laterally and 400 ft vertically, triggering a conflict alert (CA) on the controller's radar display and an aural alarm. About 3 seconds later, the air traffic controller issued a traffic advisory notifying the F-16 pilot of the position, distance, and indicated altitude of the radar target that corresponded to the Cessna, stating that the aircraft type was unknown. When the F-16 pilot replied that he was looking for the traffic, the controller issued a conditional instruction to the F-16 pilot to turn left if he did not see the airplane. The F-16 pilot did not see the airplane and responded, asking "confirm two miles?" The controller responded, "if you don't have that traffic in sight turn left heading 180 immediately." As the controller began this transmission, the F-16 pilot initiated a standard rate (approximately) left turn using the autopilot so that he could continue to visually search for the traffic; however, the airplanes continued to converge and eventually collided about 40 seconds after the controller's traffic advisory notifying the F-16 pilot of traffic. (Figure 1 in the factual report for this accident shows the calculated flight tracks for the Cessna and F-16.)

Air Traffic Controller and F-16 Pilot Performance

During postaccident interviews, the controller reported that when she observed the Cessna's target on her radar display as it departed, she thought that the airplane would remain within its local traffic pattern, which was not the case. Therefore, it was not until the airplanes were within about 3.5 nm and 400 vertical ft of one another that the controller notified the F-16 pilot of the presence of the traffic by issuing the traffic advisory, which was about 3 seconds after the ATC radar CA alarmed. (Federal Aviation Administration [FAA] Order 7110.65, Air Traffic Control, paragraph 2-1-21, "Traffic Advisories," states, in part, that a controller should "Unless an aircraft is operating within Class A airspace or omission is requested by the pilot, issue traffic advisories to all aircraft (IFR or VFR) on your frequency when, in your judgment, their proximity may diminish to less than the applicable separation minima. Where no separation minima applies, such as for VFR aircraft outside of Class B/Class C airspace, or a TRSA [terminal radar service area], issue traffic advisories to those aircraft on your frequency when in your judgment their proximity warrants it. …") 

When the controller issued the traffic advisory, about 40 seconds before the eventual collision, the F-16 and the Cessna had a closure rate of about 300 knots. If the F-16 pilot had reported the Cessna in sight after the controller's traffic advisory, the controller likely would have directed the F-16 pilot to maintain visual separation, which is a common controller technique to separate aircraft. While the controller tried to ensure separation between the airplanes, her attempt at establishing visual separation at so close a range and with the airplanes converging at such a high rate of speed left few options if visual separation could not be obtained. 

The options available to the controller when issuing instructions to the F-16 pilot to avoid the conflict included a turn, climb, some combination thereof, or not issuing an instruction at all. (An instruction to descend was not an option because the F-16 was already at the minimum vectoring altitude for the area.) The controller indicated in a postaccident interview that she chose not to instruct the F-16 to climb because the altitude indicated for the Cessna's radar target was unconfirmed (the Cessna pilot had not contacted ATC). An element informing the controller's decision-making as to which instruction to provide was likely the flow of other traffic into the airport at that time. Arriving aircraft, including the accident F-16, were being sequenced to runway 15 via the final approach course extending from the approach end of the runway. Given the traffic flow, the left turn instruction to the F-16 would have kept the airplane on a heading closer toward, rather than farther from, its destination and would have made returning the F-16 to the intended final approach course much easier. However, the controller's instruction to the F-16 pilot to turn left required the F-16's path to cross in front of the Cessna. Although this decision was not contrary to FAA guidance for air traffic controllers, it was the least conservative decision, as it was most dependent on the F-16 pilot's timely action for its success.

Further, the controller issued the instruction to turn left if the F-16 pilot did not have the Cessna in sight. The F-16 pilot responded to the controller's conditional instruction with a question ("confirm two miles?") that indicated confusion about the distance of the traffic. The F-16 pilot's attempt to visually acquire the Cessna per the controller's conditional instruction likely resulted in a slight delay in his beginning the turn. The collision likely would have been avoided had the F-16 pilot initiated the left turn, as ATC instructed, when he realized that he did not have the traffic in sight. About 7 seconds elapsed between the beginning of the controller's first conditional instruction to turn and the beginning of her subsequent conditional instruction to the F-16 pilot to turn "immediately." Analysis of the radio transmission recordings and the F-16's flight recorder data showed that, as the controller was making the subsequent conditional instruction, the F-16 pilot began turning to the left, which pointed his aircraft toward the Cessna. 

Due to the closure rate, the close proximity of the two airplanes, and human cognitive limitations, the controller did not recover from her ineffective visual separation plan, which placed the airplanes in closer proximity to each other, and switch to an alternative method of separation. The controller's best course of action would have been to instruct the F-16 pilot to turn before the airplanes came into close proximity with each other and preferably in a direction that did not cross in front of the Cessna's path.

In postaccident interviews, the controller stated that when she issued the command to the F-16 pilot to turn left "immediately," she expected that the F-16 pilot would perform a high performance maneuver and that she believed that fighter airplanes could "turn on a dime." The FAA's Aeronautical Information Manual (AIM) Pilot-Controller Glossary defines "immediately" as a term used by ATC or pilots "when such action compliance is required to avoid an imminent situation." Further, the AIM states that controllers should use the term "immediately" to "impress urgency of an imminent situation" and that "expeditious compliance by the pilot is expected and necessary for safety." As described above, the F-16 pilot did not meet her expectation that the turn be conducted at a greater-than-standard rate. 

The controller's expectation of the F-16 pilot's performance was based on her assumption that a fighter airplane would perform a high performance turn to the heading; however, this expectation of performance was not clearly communicated. Based on the controller's instructions and the actions of the F-16 pilot in response, it is clear that the term "immediately" held different expectations for both parties. Although the controller's use of the term "immediately" was in keeping with FAA guidance, further clarification of her expectation, such as directing the pilot to "expedite the turn," would have removed any ambiguity.

See-and-Avoid Concept

According to 14 Code of Federal Regulations 91.113, "Right-of-Way Rules," "when weather conditions permit, regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft." The concept that pilots are primarily responsible for collision avoidance was similarly stressed in US Air Force training documents. In addition, FAA Advisory Circular (AC) 90-48C, "Pilots' Role in Collision Avoidance," which was in effect at the time of the accident, stated that the see-and-avoid concept requires vigilance at all times by each pilot, regardless of whether the flight is conducted under IFR or VFR. (AC 90-48D replaced AC 90-48C in 2016 and contains the same statement.)

The see-and-avoid concept relies on a pilot to look through the cockpit windows, identify other aircraft, decide if any aircraft are collision threats, and, if necessary, take the appropriate action to avert a collision. There are inherent limitations of this concept, including limitations of the human visual and information processing systems, pilot tasks that compete with the requirement to scan for traffic, the limited field of view from the cockpit, and environmental factors that could diminish the visibility of other aircraft.

Factors Impacting the Pilots' Ability to Detect Other Traffic

The collision occurred in a relatively low-density air traffic environment in visual meteorological conditions (VMC). The Cessna was equipped with an operating transponder and single communication radio but was not equipped with any technologies in the cockpit that display or alert of traffic conflicts, such as traffic advisory systems, traffic alert and collision avoidance systems, or automatic dependent surveillance-broadcast systems. The Cessna had departed from a nontowered airport and was still in close proximity to the airport when the collision occurred. The Cessna pilot had not requested or received flight-following services from ATC at the time of the collision, nor was he required to do so. Based on his proximity to the departure airport, it is reasonable to expect that the Cessna pilot likely was monitoring that airport's common traffic advisory frequency (CTAF) for awareness of airplanes in the vicinity of the airport, as recommended by the FAA's AIM. Based on statements from the Cessna pilot's flight instructor and from his logbook entries, which both cited past experience communicating with ATC, it is also reasonable to assume that had the collision not occurred, the pilot likely would have contacted ATC at some point during the flight to request flight-following services.

Due to the Cessna's lack of technologies in the cockpit that display or alert of traffic conflicts and the pilot's lack of contact with ATC, his ability to detect other traffic in the area was limited to the see-and-avoid concept. While not required, had the Cessna been equipped with a second communication radio, the pilot could have used it to contact ATC while still monitoring the departure airport's CTAF. Had the Cessna pilot contacted ATC after departing and received ATC services, the controller would have had verification of the Cessna's altitude readout and its route of flight, which would have helped her decision-making process. The controller also could have provided the Cessna pilot awareness of the F-16. 

The F-16 was operating under IFR in VMC. The F-16 pilot's ability to detect other traffic was limited to the see-and-avoid concept, supplemented with ATC traffic advisories. While the F-16 pilot could use the airplane's tactical radar system to enhance his awareness of air traffic, it was designed to acquire fast-moving enemy aircraft rather than slow-moving, small aircraft and was thus unable to effectively detect the Cessna. (The radar system did detect a target 20 miles away, which is likely what led the F-16 pilot to question the location of the traffic that the controller had indicated was 2 miles away.) The F-16 was not otherwise equipped with any technologies in the cockpit that display or alert of traffic conflicts. The F-16 pilot did eventually visually acquire the Cessna but only when the airplanes were within about 430 ft of one another, about 1 second before the accident.

A factor that can affect the visibility of traffic in VMC is sun glare, which can prevent a pilot from detecting another aircraft when it is close to the position of the sun in the sky. For the F-16 pilot, the sun would have been behind and to his left as the airplanes approached one another. Although the Cessna pilot would have been heading toward the sun, the sun's calculated position would likely have been above a point obstructed by the Cessna's cabin roof and would not have been visible to the Cessna pilot. Thus, sun glare was not a factor in this accident.

Aircraft Performance and Cockpit Visibility Study

Our aircraft performance and cockpit visibility study showed that, as the accident airplanes were on converging courses, they each would have appeared as small, stationary, or slow-moving objects to the pilots. Given the physiological limitations of vision, both pilots would have had difficulty detecting the other airplane. Specifically, the study showed that the Cessna would have appeared as a relatively small object through the F-16's canopy, slowly moving from the center of the transparent heads-up display (HUD) to the left of the HUD. As the F-16 started the left turn as instructed by the air traffic controller, the Cessna moved back toward the center of the HUD and then off to its right side, where it may have been obscured by the right structural post of the HUD. It was not visible again until about 2 seconds before the collision. (Figures 3a and 5a in the factual report for this accident show the simulated cockpit visibility from the F-16 at 1100:18 and 1100:56, respectively.) The F-16 pilot reported that before the controller alerted him to the presence of traffic, he was actively searching for traffic both visually and using the airplane's targeting radar. He reported that after the controller advised him of traffic, he was looking "aggressively" to find it. By the time he was able to visually acquire the Cessna, it was too late to avert the collision.

Our investigation could not determine to what extent the Cessna pilot was actively conducting a visual scan for other aircraft. Our aircraft performance and cockpit visibility study showed that the F-16 would have remained as a relatively small and slow-moving object out the Cessna's left window (between the Cessna's 9 and 10 o'clock positions) until less than 5 seconds before the collision. Given the speed of the F-16, the Cessna pilot likely would not have had adequate time to recognize and avoid the impending collision.

Cockpit Display of Traffic Information

Although the Cessna and F-16 pilots were responsible for seeing and avoiding each other, our aircraft performance and cockpit visibility study showed that, due to the physiological limitations of vision and the relative positions of the airplanes, both pilots would have had difficulty detecting the other airplane. Research indicates that any mechanism to augment and focus pilots' visual searches can enhance their ability to visually acquire traffic. (AC 90-48D highlights aircraft systems and technologies available to improve safety and aid in collision avoidance, and our report regarding a midair collision over the Hudson River [AAR-10/05] states that "traffic advisory systems can provide pilots with additional information to facilitate pilot efforts to maintain awareness of and visual contact with nearby aircraft to reduce the likelihood of a collision. …") One such method to focus a pilot's attention and visual scan is through the use of cockpit displays and aural alerts of potential traffic conflicts. Several technologies can provide this type of alerting by passively observing and/or actively querying traffic. While the accident airplanes were not equipped with these types of systems, their presence in one or both cockpits might have changed the outcome of the event. (The images from our in-cockpit traffic display simulation are representative of the minimum operations specifications contained in RTCA document DO-317B, Minimum Operational Performance Standards for Aircraft Surveillance Applications System [dated June 17, 2014], but do not duplicate the implementation or presentation of any particular operational display exactly; the actual images presented to a pilot depend on the range scale and background graphics selected by the pilot.)

Because the Cessna pilot was not in contact with ATC and was relying solely on the see-and-avoid concept, an indication of approaching traffic might have allowed him to visually acquire the F-16 and take action to avoid it. While most systems are limited to aiding pilots in their visual acquisition of a target and do not provide resolution advisories (specific maneuvering instructions intended to avoid the collision), the augmentation of a pilot's situational awareness might allow the pilot to change the flightpath in anticipation of a conflict and, thus, avoid airplanes coming in close proximity to one another. The Cessna pilot might have noted the presence of the F-16 and its level altitude of about 1,600 ft as he continued his departure climb. With this information, the Cessna pilot might have arrested his airplane's climb as he began a visual search, thus creating an additional vertical buffer between his airplane and the approaching F-16.

While the F-16 pilot's visual search was augmented by the controller's traffic advisory, a successful outcome would have depended upon the pilot's visual acquisition of the target airplane in time to take evasive action. Our in-cockpit traffic display simulation showed that the F-16 pilot might have first observed the Cessna when it was about 15 nm away, or nearly 3 minutes before the collision. As the F-16 closed to within 6 nm of the Cessna, or slightly more than 1 minute before the collision, the conflict might have become even more apparent to the pilot showing that not only were the airplanes in close proximity laterally but also that they were only separated vertically by 600 ft. As the F-16 pilot was beginning his left turn as instructed by ATC, the presence of the Cessna would have been aurally annunciated, and its traffic symbol would have changed from a cyan color to a yellow color. The information presented on the in-cockpit traffic display would have clearly indicated that the airplanes were on a collision course that might not be resolved by a left turn and that the vertical separation between the airplanes had decreased to 300 ft. 

Consequently, an in-cockpit traffic display could have helped the F-16 pilot recognize the potential for a collision in advance of the controller's instruction to turn left. The earlier warning also could have provided him additional time to conduct his visual search for the Cessna and potentially take other preemptive action to avoid the collision. Had the F-16 been equipped with a system that was able to provide the pilot with resolution advisories, the F-16 pilot could have taken action in response to that alarm to avoid the collision, even without acquiring the Cessna visually.

Postaccident Actions

In November 2016, we issued safety recommendations to the FAA and Midwest Air Traffic Control, Robinson Aviation, and Serco (companies that operate federal contract towers) to (1) brief all air traffic controllers and their supervisors on the ATC errors in this midair collision and one that occurred on August 16, 2015, near San Diego, California; and (2) include these midair collisions as examples in instructor-led initial and recurrent training for air traffic controllers on controller judgment, vigilance, and/or safety awareness.

In November 2016, we also issued a safety alert titled "Prevent Midair Collisions: Don't Depend on Vision Alone" to inform pilots of the benefits of using technologies that provide traffic displays or alerts in the cockpit to help separate safely. (In May 2015 [revised in December 2015], we issued a safety alert titled "See and Be Seen: Your Life Depends on It" regarding the importance of maintaining adequate visual lookout.)

After the accident, the Cessna's departure airport engaged in several outreach efforts (including posting midair collision avoidance materials locally and having outreach meetings with pilots) to raise awareness regarding midair collisions and encourage contact with ATC. The airport also updated its chart supplement to note the presence of military and other traffic arriving at and departing from CHS.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The approach controller's failure to provide an appropriate resolution to the conflict between the F-16 and the Cessna. Contributing to the accident were the inherent limitations of the see-and-avoid concept, resulting in both pilots' inability to take evasive action in time to avert the collision.

HISTORY OF FLIGHT

***Refer to docket for all figures.***

On July 7, 2015, about 1101 eastern daylight time, a Cessna 150M, N3601V, and a Lockheed Martin F-16CM, operated by the US Air Force (USAF), collided in midair near Moncks Corner, South Carolina. The private pilot and passenger aboard the Cessna died, and the Cessna was destroyed during the collision. The damaged F-16 continued to fly for about 2 1/2 minutes, during which the pilot activated the airplane's ejection system. The F-16 pilot landed safely using a parachute and incurred minor injuries, and the F-16 was destroyed after its subsequent collision with terrain and postimpact fire. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the Cessna, which departed from Berkeley County Airport (MKS), Moncks Corner, South Carolina, about 1057, and was destined for Grand Strand Airport, North Myrtle Beach, South Carolina. The personal flight was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The F-16 was operating on an instrument flight rules (IFR) flight plan and had departed from Shaw Air Force Base (SSC), Sumter, South Carolina, about 1020.

Air Force F-16

According to the USAF, the F-16 pilot was assigned as pilot-in-command for a single-ship, operational check flight to verify the completion of recent corrective maintenance. The flight itinerary included practice instrument approaches at Myrtle Beach International Airport (MYR), South Carolina, and Charleston Air Force Base/International Airport (CHS), Charleston, South Carolina, before returning to SSC. Since the flight was single ship and single pilot, the pilot performed an individual flight briefing using the personal briefing guide. (The Shaw General Briefing Guide is a local USAF document that F-16 pilots use to prepare for their missions.) Before departure, squadron personnel briefed the pilot on a range of subjects, including parking location, maintenance issues, aircraft configuration, notices to airmen, weather, and the mission timeline.

After departing from SSC, the F-16 proceeded to MYR, where the pilot conducted two practice instrument approaches before continuing to CHS. According to air traffic control (ATC) radar and voice communication data provided by the Federal Aviation Administration (FAA), the F-16 pilot contacted the approach controller at CHS about 1052 and requested to perform a practice tactical air navigation system (TACAN) instrument approach to runway 15. The controller instructed the F-16 pilot to fly a heading of 260º to intercept the final approach course. About 1055, the controller instructed the F-16 pilot to descend from 6,000 ft to 1,600 ft. About that time, the F-16 was located about 34 nautical miles (nm) northeast of CHS.

Cessna

Recorded airport surveillance video showed that the Cessna, which was based at MKS, departed from runway 23. At 1057:41, a radar target displaying a visual flight rules (VFR) transponder code of 1200, and later correlated to be the accident Cessna, appeared in the vicinity of the departure end of runway 23 at MKS at an indicated altitude of 200 ft. The Cessna continued its climb and began tracking generally southeast over the next 3 minutes. For the duration of the flight, the pilot of the Cessna did not contact any ATC facilities, nor was he required to do so.

The Collision

The CHS automated radar terminal system (ARTS IIE) detected a conflict between the F-16 and the Cessna at 1059:59. According to recorded radar data, the conflict alert (CA) was presented on the radar display and aurally alarmed at 1100:13, when the F-16 and the Cessna were separated laterally by 3.5 nm and vertically by 400 ft.

At 1100:16, the CHS approach controller issued a traffic advisory advising the F-16 pilot of "traffic 12 o'clock, 2 miles, opposite direction, 1,200 [ft altitude] indicated, type unknown." At 1100:24, the F-16 pilot responded that he was "looking" for the traffic. At 1100:26, the controller advised the F-16 pilot, "turn left heading 180 if you don't have that traffic in sight." At 1100:30, the pilot asked, "confirm 2 miles?" At 1100:33, the controller stated, "if you don't have that traffic in sight turn left heading 180 immediately." As the controller was stating the instruction and over the next 18 seconds, the radar-derived ground track of the F-16 began turning southerly toward the designated heading.

At 1100:49, the radar target of the F-16 was 1/2 nm northeast of the Cessna, at an altitude of 1,500 ft, and was on an approximate track of 215º. At that time, the Cessna reported an altitude of 1,400 ft and was established on an approximate ground track of 110º. At 1100:53, the controller advised the F-16 pilot, "traffic passing below you one thousand four hundred [ft]." At 1100:54, the altitude of the F-16 remained at 1,500 ft, and the last radar return was received from the Cessna. Recorded radar data indicated that the ARTS IIE continued to provide a CA to the controller until 1101:00. The next radar target for the F-16 was not received until 1101:13. At 1101:19, the F-16 pilot transmitted a distress call, and no subsequent intelligible transmissions were received.

Several witnesses observed both airplanes in the moments leading up to the collision. One witness, located adjacent to the west branch of the Cooper River, noticed the Cessna flying overhead, roughly from west to east, and then observed the F-16 flying overhead, roughly from north to south. He estimated that the two airplanes collided at an altitude of about 900 ft. He further described that both airplanes were "very low." The F-16 struck the left side of the Cessna, and debris began falling. He reported that a large black cloud of smoke appeared after the collision but did not observe any fire. He stated that neither airplane appeared to conduct any evasive maneuvers before the collision. After the collision, the F-16 then "powered up," turned right, and flew southbound along the river.

Another witness reported that he was standing in his backyard overlooking the river. He watched as the Cessna flew by from west to east. He next saw the F-16 flying toward the Cessna, coming from the Cessna's left rear position, roughly north to south. When the F-16 collided with the left side of the Cessna, debris started falling, with some landing in his yard. He stated that it looked as if the F-16 tried to "pull up" just before impact. After the impact, the F-16 turned right and flew along the river to the south and out of sight. Once the F-16 was out of sight, he heard several loud "bang" noises.

ATC radar continued to track the F-16 as it proceeded on a southerly course. After it descended to 300 ft, radar contact was lost at 1103:17 in the vicinity of the F-16 crash site. The F-16 pilot used the airplane's emergency escape system (ejection seat) to egress, incurring minor injuries as he landed on the ground under canopy. He was subsequently met by first responders. Figure 1 shows the calculated flight track for the F-16 and the Cessna.



PERSONNEL INFORMATION

F-16 Pilot

According to USAF personnel, the pilot of the F-16 was current and qualified in the accident airplane as a four-ship flight lead. His additional duties at the time of the accident included the position of 55th Fighter Squadron Chief of Mobility. At the time of the accident, he had accumulated 2,383 total hours of military flight experience, including 624 hours in the F-16. The pilot's total flight experience included 1,055 hours at the controls of the MQ-1B (Predator) and 456 hours at the controls of the MQ-9 (Reaper), both unmanned aerial vehicles. (The remaining hours were in USAF training aircraft and flight simulators.) His recent experience included 35 hours in the 90 days before the accident and 24 hours in the 30 days before the accident, all in the F-16. The USAF reported that the pilot was medically qualified for flight duty and was wearing contact lenses at the time of the accident.

The F-16 pilot's most recent instrument checkride was completed on August 25, 2014, and his most recent mission (tactical) checkride was completed on March 24, 2015. According to USAF records, none of the pilot's post-pilot training checkrides contained discrepancies or downgrades.

The F-16 pilot reported during a postaccident interview that he had accumulated about 50 hours of civilian flying experience and possessed an FAA-issued commercial pilot certificate obtained through 14 CFR 61.73. He had not flown civilian aircraft since he began initial USAF pilot training in July 2005.

Cessna Pilot

The pilot of the Cessna held a private pilot certificate with a rating for airplane single-engine land issued on December 29, 2014. His most recent, and only, FAA third-class medical certificate was issued on February 7, 2013, with no waivers or limitations. The pilot's personal flight logbook was recovered from the wreckage and contained detailed entries between May 2012 and July 5, 2015. As of the final entry, the pilot had accumulated 244 total flight hours, of which 239 hours were in the accident airplane make and model. He had flown 58 hours in the 90 days before the accident and 18 hours in the 30 days before the accident. Review of FAA records revealed no history of accidents, incidents, violations, or pending investigations.

The Cessna pilot's primary flight instructor indicated in a postaccident interview that the pilot was "very careful" and "responsive." He stated that the pilot "enjoyed" talking to ATC and was aware of the benefits. During his instruction, he would contact ATC for flight-following without being prompted. A review of the pilot's logbook revealed that he communicated with SSC ATC on at least 9 occasions and CHS ATC at least 21 times.

Air Traffic Controller

The CHS approach controller was hired by the FAA in August 2006 and attended the FAA academy in Oklahoma City before working at the Oakland Air Route Traffic Control Center. She resigned from the FAA in September 2007 and was rehired in February 2008. She worked at CHS since her rehire. Before working for the FAA, she served as an air traffic controller in the USAF from 1998 to 2000.

The controller was qualified and current on all operating positions at CHS and held no other FAA certifications. Her most recent FAA second-class medical certificate was issued on May 21, 2014, with a requirement to wear glasses while providing ATC services. She was wearing glasses on the day of the accident.

On the day of the accident, the controller was working a regularly scheduled 0700 to 1500 shift. At the time of the accident, she was working the radar west position combined with the radar east position, which was the normal radar configuration at CHS. The radar assistant position, called radar handoff, was also staffed. About 1101, when the accident occurred, she had been working the radar west position for about 1 1/2 hours.

AIRCRAFT INFORMATION

Cessna

The white- and red-colored Cessna 150M was a single-engine, high-wing airplane with a conventional tail. It was equipped with a rotating beacon light, anticollision strobe lights, navigation position lights, and a landing light. The operational status of each lighting system at the time of the accident could not be determined. Review of the airplane's maintenance and airworthiness records revealed no evidence that any supplemental equipment, such as high intensity anticollision lights, had been installed after delivery to enhance its visual conspicuity. The airplane was not equipped with a traffic advisory system (TAS), traffic alert and collision avoidance system (TCAS), or automatic dependent surveillance-broadcast (ADS-B) equipment or displays.

The Cessna was equipped with a King KX 155 single VHF communication radio, a King KT 78 mode C transponder, and an Ameri-King AK-350 altitude encoder. Review of maintenance records revealed that the most recent transponder and encoder tests per the requirements of 14 CFR 91.413 were completed on September 8, 2008. On July 20, 2012, an overhauled transponder and new altitude encoder of the same makes and models were installed. The units were ground tested in accordance with the procedures outlined in their respective maintenance manuals, but the maintenance records did not note any tests in accordance with 14 CFR 91.413. The pitot/static system was most recently tested per the requirements of 14 CFR 91.411 on April 11, 2013. The Cessna's most recent annual inspection was completed on October 14, 2014. At the time of the inspection, the airframe had accumulated 3,651 total hours of operation.

Air Force F-16

The gray-colored F-16 was a single-seat, turbofan-powered fighter airplane. Its most recent 400 hour phase inspection was completed on June 4, 2014, and it had accumulated 237 flight hours since that time. After a flight on June 11, 2015, USAF maintenance personnel completed work on the airplane's flight control system and subsequently cleared the airplane to return to service on July 2, 2015. At the time of the accident, the airframe had accumulated 4,435 total hours of operation. The airplane was not equipped with a TAS, TCAS, or ADS-B equipment or displays.

The USAF provided general information about the limitations of the F-16 radar and "identification friend or foe" (IFF) systems (more specific information is sensitive). The F-16 was equipped with a radar unit installed in the nose of the airplane that the pilot could use to locate and "lock on" to other aircraft. The radar was forward looking and limited to a search area spanning 120º directly in front of the F-16 (60º either side of center). The radar was also limited by the size of the target and was normally used to identify targets within a 40-mile range, but other settings were available. According to USAF personnel, the radar unit was designed to acquire fast moving enemy aircraft (not slow-moving, small aircraft). USAF personnel did not believe the radar would locate a small general aviation aircraft at takeoff or climb speed. The radar acquired targets by direct energy return off the target aircraft's surface and used aircraft closure rate rather than the airspeed of the other aircraft to filter out slow-moving targets.

When operating in search target acquisition mode, traffic was displayed as a small, white square target on the radar's multifunction displays (MFD), which were located on the cockpit instrument panel, near the pilot's knees. If a target existed, a subsequent sweep of the radar would reveal a new target, and the previous image would be lighter in intensity. There were no aural alerts if a new target appeared. The pilot could place a cursor over the target and "lock" the target on the radar if he/she chose. After locking on, the pilot could obtain the mean sea level (msl) altitude of the target.

The F-16 was also equipped with an IFF interrogator. Targets identified by this system would be displayed on the MFD, but it was not an integral part of the radar. The IFF interrogator could be programmed to request specific types of responses (1 to 4); most civilian aircraft with an operating ATC transponder would provide a "type 3" response. To receive any type of response, the F-16 pilot would have to manually initiate the interrogation process, which takes about 8 to 10 seconds to sweep and display all four types of responses, each being displayed for about 2 seconds.

The F-16 was equipped with a basic autopilot providing attitude hold, heading select, and steering select in the roll axis, and attitude hold and altitude hold in the pitch axis. There was no capability for autopilot-coupled instrument approaches. There were three bank settings: go-to heading, selected steer point, and hold bank angle. While the autopilot was engaged in heading select mode and a new heading was selected, the airplane would turn at about a bank angle not to exceed 30º. According to the F-16 flight manual, the autopilot was able to maintain altitude within ±100 ft under normal cruise conditions. Manual inputs through the control stick would override autopilot functions. If specific limits were exceeded during manual override, the autopilot would disconnect.

METEOROLOGICAL INFORMATION

The area forecast that included eastern South Carolina was issued at 0445 and forecasted scattered clouds between 3,000 and 4,000 ft msl, with scattered cirrus clouds and widely scattered light rain showers and thunderstorms after 1100.

The closest facility disseminating a terminal aerodrome forecast was CHS. The last forecast published before the accident was issued at 0723. The forecast weather conditions beginning at 0800 and continuing through 1300 included variable winds at 4 knots, greater than 6 statute miles visibility, and few clouds at 4,000 ft above ground level (agl).

Review of weather radar imagery showed no precipitation in the vicinity of the accident site about the time of the accident.

The weather conditions reported at MKS at 1055 included calm wind, 10 statute miles visibility, scattered clouds at 2,600 ft agl, a temperature of 30º C, a dew point of 22º C, and an altimeter setting of 30.15 inches of mercury.

The weather conditions reported at CHS at 1055 included wind from 220º true at 7 knots, 10 statute miles visibility, scattered clouds at 4,000 ft agl, a temperature of 30º C, a dew point of 22º C, and an altimeter setting of 30.15 inches of mercury.

At the time of the accident, the sun was about 57º above the horizon at an azimuth of about 99º.

AIRPORT INFORMATION

CHS has two intersecting runways oriented in a 15/33 and 03/21 configuration, at an elevation of 46 ft. The airport is served by numerous instrument approaches, including a VOR [very high omnidirectional range]/DME [distance measuring equipment] or TACAN approach to runway 15. The minimum altitude for the intermediate portion of the approach was 1,600 ft msl, while the minimum crossing altitude at the final approach fix, located 2.8 nm from the runway 15 threshold, was 1,100 ft msl.

ATC services at the airport are provided continuously by a combined ATC tower and terminal radar approach control (TRACON) facility. The CHS TRACON airspace extends for an approximate 40-nm radius from CHS, from the surface to 10,000 ft msl. Radar data are displayed to air traffic controllers at CHS via the ARTS IIE, with the radar feed from the airport surveillance radar (ASR-9), located at CHS.

The airport is surrounded by class C airspace, defined as that airspace extending from the surface up to and including 4,000 ft msl, within a 5-nm radius of CHS and that airspace extending from 1,200 ft msl up to and including 4,000 ft msl, within a 10-mile radius of CHS. There is no specific pilot certification required to operate within the class C airspace, but, according to 14 CFR 91.215, aircraft are required to be equipped with a two-way radio with an operable radar beacon transponder with automatic altitude reporting equipment. According to 14 CFR 91.130, before entering the class C airspace, two-way radio communication must be established and subsequently maintained with the ATC facility providing services.

Pilots requesting ATC services at CHS are required to contact the ATC facility on the publicized radio frequency and provide their position, altitude, radar beacon code, destination, and the nature of their request. Radio contact should be initiated far enough from the class C airspace boundary to preclude entering class C airspace before two-way radio communications are established. Beyond the class C airspace is an outer area that extends to a 20-nm radius of the airport. There were no specific communications or transponder requirements to operate in this area; however, approach control services could still be provided by ATC when operating in the outer area.

MKS, the Cessna's departure airport, is located about 17 nm north of CHS and is outside the CHS class C airspace. The airspace surrounding MKS and encompassing the collision location is designated as class E and extends from 700 ft agl to 17,999 ft msl. There are no two-way radio communication or transponder use requirements for operation in class E airspace. The established minimum vectoring altitude for ATC in this area is 1,600 ft, which represented the lowest altitude available to controllers when providing radar vectors to aircraft operating under IFR. Figure 2 shows an FAA sectional chart depicting CHS and class C airspace, MKS, and the approximate collision location.



An instrument military training route (MTR), IR-18, transits generally south to north with an altitude structure of 5,000 to 7,000 ft msl, and is located about 1 nm east of MKS. A visual MTR, VR-1040/1041, transits generally east to west with an altitude structure of 200 to 1,500 ft agl and is located about 5 nm northwest of MKS. (The F-16 was not operating on either of these MTRs.) Several military operations areas, two USAF airbases, and a National Guard airbase are located within 60 nm of MKS. The airport/facility directory entry for MKS did not provide any warning or cautions regarding low altitude, high speed military air traffic in the vicinity of the airport.

FLIGHT RECORDERS

A crash-survivable memory unit (CSMU) was recovered from the wreckage of the F-16, and the digital flight control system seat data recorder was recovered from the airplane's ejection seat. Both memory units were forwarded to the airframe manufacturer for data extraction under the supervision of a National Transportation Safety Board (NTSB) vehicle recorder specialist. The data were downloaded normally with no anomalies noted.

WRECKAGE AND IMPACT INFORMATION

Cessna

The wreckage of the Cessna was recovered in the vicinity of its last observed radar target, over the west branch of the Cooper River. Components from both airplanes were spread over an area to the north and west of that point, extending for about 1,200 ft. The largest portions of the Cessna's airframe included a relatively intact portion of the fuselage aft of the main landing gear and the separate left and right wings, all of which were within 500 ft northwest of the airplane's final radar-observed position. Portions of the cabin interior, instrument panel, fuel system, and engine firewall were found distributed throughout the site. The engine, propeller, and nose landing gear assembly were not recovered. The lower aft engine cowling of the F-16 was also recovered in the immediate vicinity of the Cessna's aft fuselage, while the F-16's engine augmenter was recovered about 1,500 ft southwest. Small pieces of the F-16's airframe were also distributed throughout the accident site.

Both of the Cessna's wings displayed uniform leading-edge crush damage throughout their spans that was oriented aft and upward. Paint transfer and rub markings (consistent with paint from the F-16) oriented from left to right were observed along the upper forward surfaces of both wings. Both fuel tanks were ruptured, and evidence of heat damage and thermal paint blistering were observed on the upper surface of the right wing. Flight control continuity was traced through overload-type cable separations from the cabin area to each flight control surface. Measurement of the pitch trim actuator showed a position consistent with a 3º-to-4º deflection of the tab in the nose down direction, and measurement of the flap actuator showed a position consistent with the flaps having been in the retracted position.

Air Force F-16

The F-16 wreckage site was located about 6 nm south of the Cessna wreckage site. The F-16 wreckage path was about 700 ft long and oriented roughly 215º, with portions of the airframe distributed along the wreckage path. The wreckage displayed significant ground impact and postimpact fire-related damage.

MEDICAL AND PATHOLOGICAL INFORMATION

The Department of Pathology and Lab Medicine, Medical University of South Carolina, determined that the cause of death for both occupants of the Cessna was "blunt trauma." The FAA's Civil Aerospace Medical Institute performed postaccident toxicological testing on tissue specimens from the Cessna pilot. The specimens tested negative for a wide range of drugs, including major drugs of abuse. Although the specimens tested positive for ethanol, the levels of ethanol were consistent with postmortem ethanol production.

A Department of Defense Armed Forces medical examiner scientist performed postaccident toxicological testing on blood and urine specimens from the F-16 pilot, and the specimens tested negative for carbon monoxide, ethanol, and major drugs of abuse.

TESTS AND RESEARCH

Aircraft Performance and Cockpit Visibility Study

The NTSB's investigation examined the ability of the Cessna and F-16 pilots to see and avoid the other aircraft. To determine approximately how each aircraft would appear in the pilots' fields of view, the position of the "target" aircraft in a reference frame attached to the "viewing" aircraft must be calculated. This calculation depends on the positions and orientation (pitch, roll, and yaw angles) of each aircraft, as well as the location of the pilots' eyes relative to the cockpit windows. Data for the F-16 were derived from its CSMU, while orientation information for the Cessna was estimated based on an analysis of the radar data.

After the position and orientation of each airplane were determined, the position of each airplane in the body axis system of the other was calculated. These relative positions then determined where the "target" airplanes likely would have appeared in the fields of vision of the pilots of the "viewing" airplanes. The study assumed a nominal pilot seating (and eye) position in each cockpit and evaluated a matrix of eye displacements from the nominal eye position. For this study, the relative positions of the two airplanes were calculated beginning when the Cessna became visible on radar and then at 1-second intervals up to the collision. The time, location, and altitude of the collision were determined based on extrapolation of the radar and F-16 CSMU data and on the location of the main Cessna wreckage. The locations of the structures and transparencies of the F-16 and Cessna in the pilots' fields of view were determined from the interior and exterior dimensions of representative airplanes, as measured using a laser scanner. The structural obscurations to each pilot's view were merged with the calculated relative position data and are discussed below. The variations in eye position changed the timing of the obscurations of the opposite aircraft by less than +/-1.5 seconds at any given point.


At 1100:16, when the controller provided the initial traffic advisory to the F-16 pilot, the F-16 was in a wings-level attitude, at an altitude of about 1,570 ft, on a ground track of 252º, and at a ground speed of 253 knots. The Cessna's calculated position was 3.25 nm from the F-16, at a position directly ahead (about 12 o'clock), and at an altitude of roughly 1,200 ft. The Cessna's ground track was 109º, and it was climbing at a rate of about 240 ft per minute. The aircraft performance and cockpit visibility study showed that, at 1100:18, the Cessna would have appeared to the F-16 pilot as a very small, stationary object just above the horizon and near the center of the airplane's heads up display (HUD) (see figure 3a); the F-16 would have appeared to the Cessna pilot as a small, stationary object just above the horizon, but outside of the left cockpit door window, near the forward vertical post of the door frame (see figure 3b).



At 1100:26, when the controller advised the F-16 pilot, "turn left heading 180 if you don't have that traffic in sight," the relative positions changed slightly, with the Cessna moving slightly to the left but still remaining within the F-16's HUD, and the F-16 moving slightly aft in the Cessna pilot's left window.

At 1100:33, when the controller stated, "If you don't have that traffic in sight turn left heading 180 immediately" and as the F-16 began banking to the left, the F-16 pilot's view of the Cessna would have been obscured behind the left structural frame of the HUD. The position of the F-16 would have remained unchanged to the Cessna pilot.

At 1100:49, as the F-16 was executing its left turn at a bank angle of 30º, the Cessna would have become more discernable in the lower right portion of the F 16 pilot's HUD (see figure 4a). The F-16 would also have become more discernable, visible through the Cessna pilot's left window at a point just forward of the wing strut attachment point (see figure 4b).




At 1100:53, when the controller advised the F-16 pilot, "traffic passing below you" at 1,400 ft, the F-16 was flying at an altitude of 1,480 ft, while the estimated altitude of the Cessna was 1,440 ft. The closure rate of both airplanes at this point was 264 knots. The Cessna would have been visible to the right of the structural frame of the F 16's HUD, while the F-16 would have appeared to the Cessna pilot in largely the same position but with a more defined shape.

Over the next 3 seconds, the airplanes continued to approach each other, with the F-16 approaching the Cessna from its left and slightly above. The Cessna would have been completely obscured by the lower right cockpit structure of the F-16, as the airplane banked in its turn to the left (see figure 5a). The F 16 would have become partially obscured by the left wing strut (see figure 5b).




In-Cockpit Traffic Display Simulation

The FAA's Aeronautical Information Manual (AIM) (dated December 10, 2015, and revised on May 26, 2016), paragraph 4-5-7, states that ADS B is a surveillance technology deployed throughout the National Airspace System. The ADS-B system is composed of aircraft avionics and a ground infrastructure. Onboard avionics determine the position of an aircraft by using the GPS and transmitting its position along with additional information about the aircraft to ground stations for use by ATC and other ADS-B services. This information is transmitted at a rate of approximately once per second. ADS-B avionics can have the ability to both transmit and receive information. The transmission of ADS-B information from an aircraft is known as ADS B Out. The receipt of ADS-B information by an aircraft is known as ADS-B In. On January 1, 2020, all aircraft operating within the airspace defined in 14 CFR 91.225 will be required to transmit the information defined in 14 CFR 91.227 using ADS-B Out avionics.

The ADS-B capabilities that enhance a pilot's awareness of airborne traffic in their vicinity are described in FAA Advisory Circular (AC) 20-172B, "Airworthiness Approval for ADS-B In Systems and Applications." Per the AC, this capability allows an appropriately equipped aircraft to receive and display another aircraft's ADS-B Out information, as well as ground station broadcast information, from services like traffic information services-broadcast (TIS-B) and automatic dependent surveillance-rebroadcast (ADS-R). The received information is processed by onboard avionics and presented to the flight crew on a display. ADS-B In avionics enable a number of aircraft surveillance applications and can enhance visual acquisition by displaying nearby traffic on a plan view (bird's eye view) relative to own-ship. The traffic information assists pilots in visually acquiring traffic out the window while airborne but does not relieve them of see-and-avoid responsibilities. Additionally, the information derived through ADS-B In applications can be used to provide voice annunciations to flight crews to draw attention to alerted traffic.

The images from the NTSB's in-cockpit traffic display simulation presented in figures 6 and 7 are representative of the minimum operations specifications for such displays contained in RTCA document DO-317B but do not duplicate the implementation or presentation of any particular operational display exactly. The actual images presented to a pilot depend on the range scale and background graphics selected by the pilot (which could reflect various implementations and combinations of moving maps, terrain elevation data, and weather information, rather than the simple black background presented here).

For this accident, simulated in-cockpit displays of traffic information for both the F-16 and Cessna were created based on the TIS-B information that would have been displayed to the pilot of each airplane assuming that both aircraft were equipped with ADS-B In capability and avionics capable of displaying and aurally annunciating the traffic information. In addition, the simulation assumes that at least one ADS-B Out equipped aircraft was operating in the vicinity of the two accident aircraft in order to trigger the broadcast of TIS-B information from a ground station, as currently, aircraft equipped with only ADS-B In cannot trigger the broadcast of this information.

The NTSB's in-cockpit traffic display simulation for the F-16 indicates that at 1058:06, an open (outlined), cyan-colored, arrowhead-shaped target representing the Cessna would have appeared at the F 16's 12 o'clock position (straight ahead), 15 nm from and 1,300 ft below the F-16. The Cessna would have been the only target within that range from that time up to the time of the collision at 1100:57. As the airplanes approached each other, the Cessna target would have been shown turning left from west to east and then approaching the F-16 from its 12 o'clock position, slightly to the right of the F-16's flightpath, and climbing. The heading depicted by the Cessna symbol as the aircraft converged would have indicated that the Cessna's projected flightpath would cross the F-16's flightpath from right to left. At 1059:47, the Cessna symbol would have changed from an open cyan arrowhead to a filled cyan arrowhead, as the Cessna closed within 6 nm horizontally and 600 ft vertically of the F-16.

At 1100:35, as the F-16 banked into its left turn toward the south, the pilot would have received an aural alert associated with the Cessna, which by then had closed within 2 nm horizontally and 300 ft vertically. The aural alert would have advised, "Traffic, 12 o'clock, low, 2 miles." As shown in figure 6, the Cessna symbol would have changed to a filled yellow arrowhead, enclosed by a yellow circle. As the F-16 continued in its left turn, the Cessna target would have rotated to the right side of the F-16's projected course, with its heading still projected to intercept that course. At 1100:56, one second before the collision, the F-16 would have received a second aural alert of "Traffic, 2 o'clock, same altitude, zero miles." The symbol representing the Cessna would have depicted it 100 ft below the F-16 (see figure 6).


The in-cockpit traffic display simulation for the Cessna indicates that at 1058:05, an open cyan target representing the F-16 would have appeared at the Cessna's 8 o'clock position, 15 nm from and 1,300 ft above the Cessna. The F-16 would have been one of two targets within that range from that time up to the time of the collision at 1100:57. The other target would have appeared between the Cessna's 12 and 1 o'clock position, about 11 nm from and 1,300 ft above the Cessna. As the Cessna turned left toward the east, the F-16 target would have rotated to the Cessna's 11 o'clock position and been depicted flying toward the Cessna. The other aircraft would have rotated to the Cessna's 3 o'clock position and been depicted flying away from the Cessna. At 1059:47, the F-16 symbol would have changed from an open cyan arrowhead to a filled cyan arrowhead, as the F-16 closed within 6 nm horizontally and 600 ft vertically of the Cessna.

At 1100:35, as the F-16 banked into its left turn toward the south, the Cessna pilot would have received an aural alert associated with the F-16, which by then had closed within 2 nm horizontally and 300 ft vertically. The aural alert would have advised, "Traffic, 11 o'clock, high, 1 mile." As shown in figure 7, the F-16 symbol would have changed to a filled yellow arrowhead, enclosed by a yellow circle. The Cessna would not have received a second aural alert for the F-16, but the F-16 symbol would have remained in alert status (filled yellow arrowhead enclosed by a yellow circle) until the collision.


ORGANIZATIONAL AND MANAGEMENT INFORMATION

USAF Mid-Air Collision Avoidance Program

The USAF has a Mid-Air Collision Avoidance (MACA) program detailed in Air Force Instruction (AFI) 91-202, dated June 24, 2015. According to AFI 91-202, USAF flying units must have a written MACA program, and the unit safety office is responsible for its creation, documentation, and upkeep. The 20th Fighter Wing (FW) Safety Office administered the Shaw Air Force Base MACA program. The required elements are a MACA pamphlet and a poster, primarily designed for use in the civilian community. The program includes civilian outreach and incorporates interaction with pilot advocacy organizations, the FAA, local airports, and fixed base operators. The 20th FW Safety Office also maintains a public website populated with the MACA program products and other safety information. According to 20th FW Safety Office personnel, activities related to MACA are coordinated with two other military bases: Charleston Joint Base and McEntire Joint National Guard Base. The Charleston Joint Base Flight Safety office held MACA seminars at MKS in June 2012, January 2014, and March 2015.

ADDITIONAL INFORMATION

Postaccident Interviews

F-16 Pilot

Members of the USAF Accident Investigation Board interviewed the F-16 pilot after the accident. He reported that he had the radar configured for a 20- and 40-mile range, manually alternating back and forth, and could not recall if his IFF interrogator was set up to receive civilian transponder replies. He was using a scan pattern that included looking outside; checking instruments for altitude, airspeed, and heading; and checking the radar display.

The F-16 pilot indicated that he had acquired and locked on a radar target 20 miles away. He stated that shortly thereafter, the controller issued an alert for traffic at his 12 o'clock position, 2 miles away, at 1,200 ft. He remarked that a 2-mile call was the "…closest call I've ever received" and that it was "…a big alert for me." He then asked the controller to "confirm two miles"; he indicated in a postaccident interview that he asked that question because he was looking at traffic on his radar at 20 miles away. He then began aggressively looking to visually acquire the airplane and recalled a command from the controller to turn left "immediately" to a heading of 180º. He stated that he used the autopilot to execute the turn so that he could continue to search outside for the traffic. The autopilot turn used 30º of bank and standard rate, or 3º per second of turn. He continued to search for the traffic until he observed the Cessna directly in front of his airplane, "within 500 feet." He then applied full aft control stick inputs to avoid a collision, but it was "too late." He estimated that the time from initial sighting of the Cessna to the impact was less than 1 second. After the collision, he attempted to maintain control of his airplane; however, once he determined that continued controlled flight was not possible, he initiated his emergency egress.

Air Traffic Controller

The air traffic controller described the traffic on the day of the accident as light and routine, with nothing out of the ordinary. Several USAF fighter aircraft from SSC were making approaches to CHS when the F-16 entered the airspace from the northeast and requested a TACAN approach. The controller told the pilot to expect the requested approach and provided climb-out instructions after completing the approach. She issued a radar vector of 260º to intercept the 10- to 15-mile final approach course for the instrument approach. The intent of this vector was to keep the F-16 south of, and to avoid overflying, MKS. The controller stated that she then directed the F-16 to descend and maintain 1,600 ft and was "pretty much done with him" while she worked other traffic, including a flight of two other F 16s. She had descended the accident airplane to 1,600 ft because that was the minimum vectoring altitude at CHS. She stated that this was her usual technique; getting aircraft to their final altitude quickly allowed her more efficient use of her time.

When the controller initially noticed the Cessna depart from MKS, she thought that it would remain in the local VFR traffic pattern. She described that, generally, pattern traffic at MKS was rare and, when present, typically stayed below 1,000 ft. She then descended the other two aircraft flight of F-16s to sequence them behind the accident F-16 and to get them around other traffic. Shortly after, she asked the two-aircraft flight to expedite its descent to 3,000 ft and noticed that the Cessna was climbing above 1,000 ft. She responded by advising the F-16 pilot, hoping that he would be able to visually acquire the traffic, but the F-16 pilot did not report the traffic in sight. She advised the F-16 pilot to turn left heading 180 if he did not have the traffic in sight.

As the radar targets were continuing to close on one another, she directed the F-16 pilot that if he did not have the traffic in sight to turn left heading 180 immediately. She reported that the 180 heading assignment was preferred over a turn to the north because the turn was quicker, and she believed that "fighters could turn on a dime." She stated that her expectation was that the word "immediately" meant to react now and that, with a fighter aircraft, it meant to do a "max performance turn" to the heading. She stated that she did not recall seeing or hearing a CA generated by the ATC radar system. The controller indicated in a postaccident interview that she chose not to direct the F 16 to climb because the altitude indicated for the Cessna's radar target was unconfirmed.

The controller advised the F-16 pilot that the Cessna had passed below him and thought the two aircraft were clear of each other until she saw the Cessna's radar target disappear followed by the F 16 pilot's distress call. She briefly initiated a call to the pilot and then turned to the radar handoff controller and told him "I don't know what to do." The radar handoff controller advised her to "separate what you've got."

ATC Radar Equipment

The radar display system in use at CHS at the time of this accident, ARTS IIE, is designed to support one or two sensors and up to 22 displays in two different configurations and can process 256 simultaneous tracks per sensor. At the time of the accident, there were no known or reported equipment discrepancies with the ARTS IIE system that would have affected the controller's ability to provide ATC services.

The ARTS IIE has numerous capabilities and functions to help controllers with strategic and tactical decision-making. One of these functions is the CA/mode C intruder, which provides controllers with visual and immutable aural warnings for aircraft that are or will be in dangerous proximity to one another. A CA provides a visual presentation on the radar scope display associated with the conflicting aircraft and an aural alarm when conditions warrant. These conditions are based on vertical and horizontal parameters established for the environment in which the aircraft are operating. For example, in an en route environment where aircraft are operating at higher altitudes and faster speeds, the parameters would be more sensitive when compared to an airport environment, where aircraft operate closer to each other and at lower speeds. For a predicted alert, the ARTS IIE evaluates a developing conflict for two of three consecutive radar sweeps. The average sweep of an ASR (a 360º scan) takes about 5 seconds.

The CHS ARTS IIE detected the conflict between the F-16 and the Cessna at 1059:59, and the CA was presented on the radar scope with an accompanying aural alert at 1100:13. The ARTS IIE continued to provide a CA to the controller until 1101:00. As the controller stated in her postaccident interview, she did not recall seeing or hearing the CA, but review of archived ATC audio revealed that her initial traffic advisory to the F-16 began at 1100:16, 3 seconds after the CA alerted. A postaccident test of the CA alarm at CHS revealed that it worked properly.

FAA and USAF Rules, Regulations, and Guidance to Pilots

Title 14 CFR 91.113 addresses aircraft right-of-way rules and states, in part, the following:

(b) General. When weather conditions permit, regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft.

The FAA's AIM, dated April 3, 2014, paragraph 5-5-8, includes pilot procedures for see-and-avoid while in flight and states, "When meteorological conditions permit, regardless of type of flight plan or whether or not under control of a radar facility, the pilot is responsible to see and avoid other traffic, terrain, or obstacles."

The AIM, paragraph 4-1-9, also describes operations to/from airports without an operating control tower and the use of a common traffic advisory frequency (CTAF) and states, in part, the following:

a. Airport Operations Without Operating Control Tower

1. There is no substitute for alertness while in the vicinity of an airport. It is essential that pilots be alert and look for other traffic and exchange traffic information when approaching or departing an airport without an operating control tower…To achieve the greatest degree of safety, it is essential that all radio-equipped aircraft transmit/receive on a common frequency identified for the purpose of airport advisories.

b. Communicating on a Common Frequency

The key to communicating at an airport without an operating control tower is selection of the correct common frequency…A CTAF is a frequency designated for the purpose of carrying out airport advisory practices while operating to or from an airport without an operating control tower.

The AIM describes the recommended communication procedures regarding departure aircraft on the CTAF and states, "Pilots of inbound traffic should monitor and communicate as appropriate on the designated CTAF from 10 miles to landing. Pilots of departing aircraft should monitor/communicate on the appropriate frequency from start-up, during taxi, and until 10 miles from the airport unless the CFRs or local procedures require otherwise."

The AIM, paragraph 5-5-10, describes the manner in which pilots could expect to receive traffic advisories from ATC and states the following:

a. Pilot.
1. Acknowledges receipt of traffic advisories.
2. Informs controller if traffic in sight.
3. Advises ATC if a vector to avoid traffic is desired.
4. Does not expect to receive radar traffic advisories on all traffic. Some aircraft may not appear on the radar display. Be aware that the controller may be occupied with higher priority duties and unable to issue traffic information for a variety of reasons.
5. Advises controller if service is not desired.

b. Controller.
1. Issues radar traffic to the maximum extent consistent with higher priority duties except in Class A airspace.
2. Provides vectors to assist aircraft to avoid observed traffic when requested by the pilot.
3. Issues traffic information to aircraft in the Class B, Class C, and Class D surface areas for sequencing purposes.
4. Controllers are required to issue to each aircraft operating on intersecting or nonintersecting converging runways where projected flight paths will cross.

The Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-24A), section 13, addresses scanning procedures for visually acquiring traffic:

The pilot can contribute to collision avoidance by being alert and scanning for other aircraft. This is particularly important in the vicinity of an airport.

Effective scanning is accomplished with a series of short, regularly spaced eye movements that bring successive areas of the sky into the central visual field. Each movement should not exceed 10º, and each should be observed for at least 1 second to enable detection. Although back and forth eye movements seem preferred by most pilots, each pilot should develop a scanning pattern that is most comfortable and then adhere to it to assure optimum scanning. Even if entitled to the right-of-way, a pilot should yield if another aircraft seems too close.

(The most recent version of this handbook, FAA-H-8083-25B, was published in 2016.)

The AIM Pilot-Controller Glossary defines "immediately" as a term used by ATC or pilots when such action compliance was required to avoid an "imminent situation."

The AIM, paragraph 4-4-10, states, in part, the following about adherence to clearance:

a. When air traffic clearance has been obtained under either visual or instrument flight rules, the pilot-in-command of the aircraft must not deviate from the provisions thereof unless an amended clearance is obtained. When ATC issues a clearance or instruction, pilots are expected to execute its provisions upon receipt. ATC, in certain situations, will include the word "IMMEDIATELY" in a clearance or instruction to impress urgency of an imminent situation and expeditious compliance by the pilot is expected and necessary for safety...

b. When a heading is assigned or a turn is requested by ATC, pilots are expected to promptly initiate the turn, to complete the turn, and maintain the new heading unless issued additional instructions.

Air Force Manual 11-248, dated January 19, 2011, T-6 Primary Flying, addresses clearing procedures in section 1.16:

1.16. Clearing. Each crewmember is responsible for collision avoidance - regardless of rank, experience, or cockpit position - whether instrument flight rules (IFR) or VFR….Pilots have the responsibility to clear the aircraft in all directions, and although the use of radar monitoring, assigned areas, or ATC separation can assist in ensuring clearance, it does not relieve pilots of the responsibility. The following principles apply to clearing regardless of flight conditions:

1.16.1. Visual detection is the most important factor in clearing for other aircraft.

FAA Guidance to Air Traffic Controllers

FAA Order 7110.65, Air Traffic Control, prescribes ATC procedures and phraseology for use by personnel providing ATC services. Paragraph 2-1-2, "Duty Priority," states, in part, that controllers should "give first priority to separating aircraft and issuing safety alerts as required in this order. Good judgment must be used in prioritizing all other provisions of this order based on the requirements of the situation at hand."

Paragraph 2-1-5, "Expeditious Compliance," states, in part, that controllers should "use the word 'immediately' only when expeditious compliance is required to avoid an imminent situation."

Paragraph 2-1-6, "Safety Alerts," states, in part, the following:

Issue a safety alert to an aircraft if you are aware the aircraft is in a position/altitude that, in your judgment, places it in unsafe proximity to terrain, obstructions, or other aircraft….

Note-
1. The issuance of a safety alert is a first priority…once the controller observes and recognizes a situation of unsafe aircraft proximity to terrain, obstacles, or other aircraft. Conditions, such as workload, traffic volume, the quality/limitations of the radar system, and the available lead time to react are factors in determining whether it is reasonable for the controller to observe and recognize such situations. While a controller cannot see immediately the development of every situation where a safety alert must be issued, the controller must remain vigilant for such situations and issue a safety alert when the situation is recognized….

b. Aircraft Conflict/Mode C Intruder Alert. Immediately issue/initiate an alert to an aircraft if you are aware of another aircraft at an altitude that you believe places them in unsafe proximity. If feasible, offer the pilot an alternate course of action. When an alternate course of action is given, end the transmission with the word "immediately."

Phraseology—
Traffic Alert (call sign) (position of aircraft) Advise
You turn left/right (heading),

and/or

Climb/Descend (specific altitude if appropriate)
Immediately.

Paragraph 2-1-21, "Traffic Advisories," states the following:

Unless an aircraft is operating within Class A airspace or omission is requested by the pilot, issue traffic advisories to all aircraft (IFR or VFR) on your frequency when, in your judgment, their proximity may diminish to less than the applicable separation minima. Where no separation minima applies, such as for VFR aircraft outside of Class B/Class C airspace, or a TRSA [terminal radar service area], issue traffic advisories to those aircraft on your frequency when in your judgment their proximity warrants it. Provide this service as follows:

a. To radar identified aircraft:

1. Azimuth from aircraft in terms of the 12-hour clock, or
2. When rapidly maneuvering aircraft prevent accurate issuance of traffic as in 1 above, specify the direction from an aircraft's position in terms of the eight cardinal compass points (N, NE, E, SE, S, SW, W, and NW). This method must be terminated at the pilot's request.
3. Distance from aircraft in miles.
4. Direction in which traffic is proceeding and/or relative movement of traffic.
Note-
Relative movement includes closing, converging, parallel same direction, opposite direction, diverging, overtaking, crossing left to right, crossing right to left.
5. If known, type of aircraft and altitude.
Phraseology-Traffic, (number) o'clock, or when appropriate,

(direction) (number) miles, (direction)-bound and/or (relative movement),

and if known,

(type of aircraft and altitude).

or

When appropriate,

(type of aircraft and relative position), (number of feet) feet above/below you.

If altitude is unknown,

Altitude unknown.

Example-
"Traffic, eleven o'clock, one zero miles, southbound, converging, Boeing Seven Twenty Seven, one seven thousand."
"Traffic, twelve o'clock, one five miles, opposite direction, altitude unknown."
"Traffic, ten o'clock, one two miles, southeast bound, one thousand feet below you."
6. When requested by the pilot, issue radar vectors to assist in avoiding the traffic, provided the aircraft to be vectored is within your area of jurisdiction or coordination has been effected with the sector/facility in whose area the aircraft is operating.
7. If unable to provide vector service, inform the pilot.
8. Inform the pilot of the following when traffic you have issued is not reported in sight:
(a) The traffic is no factor.
(b) The traffic is no longer depicted on radar.
Phraseology-
Traffic no factor/no longer observed,

or

(number) o'clock traffic no factor/no longer observed, 

or

(direction) traffic no factor/no longer observed.

b. To aircraft that are not radar identified:
1. Distance and direction from fix.
2. Direction in which traffic is proceeding.
3. If known, type of aircraft and altitude.
4. ETA over the fix the aircraft is approaching, if appropriate.
Phraseology-
Traffic, (number) miles/minutes (direction) of (airport or fix), (direction)-bound,

and if known,

(type of aircraft and altitude),

estimated (fix) (time),

or

traffic, numerous aircraft vicinity (location).

If altitude is unknown,

Altitude unknown.

Example-
"Traffic, one zero miles east of Forsythe V-O-R, Southbound, M-D Eighty, descending to one six thousand."
"Traffic, reported one zero miles west of Downey V-O-R, northbound, Apache, altitude unknown, estimated Joliet V-O-R one three one five."
"Traffic, eight minutes west of Chicago Heights V-O-R, westbound, Mooney, eight thousand, estimated Joliet V-O-R two zero three five."
"Traffic, numerous aircraft, vicinity of Delia airport."

c. For aircraft displaying Mode C, not radar identified, issue indicated altitude.
Example-
"Traffic, one o'clock, six miles, eastbound, altitude indicates six thousand five hundred."

The See-and-Avoid Concept

The FAA issued AC 90-48C, "Pilots' Role in Collision Avoidance," in 1983 to alert all pilots "…to the potential hazards of midair collisions and near midair collision [NMAC], and to emphasize those basic problem areas related to the human causal factors where improvements in pilot education, operating practices, procedures, and improved scanning techniques are needed to reduce midair conflicts." (This version of the AC was in place at the time of the accident; an updated version, AC 90-48D, was issued in April 2016 and is discussed further below.)

AC 90-48C stated that each person operating an aircraft, regardless of whether the operation was conducted under IFR or VFR, shall maintain a vigilant lookout for other aircraft at all times. Regarding visual scanning, the AC specifically stated that "Pilots should remain constantly alert to all traffic movement within their field of vision, as well as periodically scanning the entire visual field outside of their aircraft to ensure detection of conflicting traffic" (emphasis in the original). AC 90-48C also described several specific methods that pilots could use to visually acquire other traffic.

AC 90-48C also discussed the use of ATC services:

One of the major factors contributing to the likelihood of NMAC incidents in terminal areas that have an operating air traffic control (ATC) system has been the mix of known arriving and departing aircraft with unknown traffic. The known aircraft are generally in radio contact with the controlling facility (local, approach, or departure control) and the other aircraft are neither in two-way radio contact nor identified by ATC at the time of the NMAC. (emphasis in the original)

The AC recommended that pilots use ATC traffic advisory services but stressed that those services do not lessen the pilot's obligation to see and avoid other traffic.

Finally, the AC provided data on the time required for a pilot to recognize an approaching aircraft and execute an evasive maneuver. The total time to identify an approaching aircraft, recognize a collision course, decide on action, execute the control movement, and allow the aircraft to respond was estimated to be around 12.5 seconds.

In 1991, the Australian Transport Safety Bureau (ATSB) published a research report titled Limitations of the See-and-Avoid Principle. The report discusses the role of the see-and-avoid concept in preventing collisions and some of its inherent limitations:

Cockpit workload and other factors reduce the time that pilots spend in traffic scans. However, even when pilots are looking out, there is no guarantee that other aircraft will be sighted. Most cockpit windscreen configurations severely limit the view available to the pilot. The available view is frequently interrupted by obstructions such as window-posts which totally obscure some parts of the view and make other areas visible to only one eye....Visual scanning involves moving the eyes in order to bring successive areas of the visual field onto the small area of sharp vision in the centre of the eye. The process is frequently unsystematic and may leave large areas of the field of view unsearched….The physical limitations of the human eye are such that even the most careful search does not guarantee that traffic will be sighted….An object which is smaller than the eye's acuity threshold is unlikely to be detected and even less likely to be identified as an approaching aircraft….The human visual system is better at detecting moving targets than stationary targets, yet in most cases, an aircraft on a collision course appears as a stationary target in the pilot's visual field. The contrast between an aircraft and its background can be significantly reduced by atmospheric effects, even in conditions of good visibility. An approaching aircraft, in many cases, presents a very small visual angle until a short time before impact. In addition, complex backgrounds such as ground features or clouds hamper the identification of aircraft via a visual effect known as 'contour interaction'. This occurs when background contours interact with the form of the aircraft, producing a less distinct image. Even when an approaching aircraft has been sighted, there is no guarantee that evasive action will be successful.

The ATSB report also discusses the value of alerted versus unalerted searches for traffic:

A traffic search in the absence of traffic information is less likely to be successful than a search where traffic information has been provided because knowing where to look greatly increases the chance of sighting the traffic (Edwards and Harris 1972). Field trials conducted by John Andrews found that in the absence of a traffic alert, the probability of a pilot sighting a threat aircraft is generally low until a short time before impact. Traffic alerts were found to increase search effectiveness by a factor of eight. A traffic alert from ATS or from a radio listening watch is likely to be similarly effective (Andrews 1977, Andrews 1984, Andrews 1987).

The ATSB report concludes, in part, that "The see-and-avoid principle in the absence of traffic alerts is subject to serious limitations….Unalerted see-and-avoid has a limited place as a last resort means of traffic separation at low closing speeds but is not sufficiently reliable to warrant a greater role in the air traffic system."

Cockpit Display of Traffic Information

In April 2016, the FAA published an update to "Pilots' Role in Collision Avoidance" (AC 90 48D), which highlights aircraft systems and technologies available to improve safety and aid in collision avoidance. Among those technologies, the recommended safety equipment includes TAS, TCAS (I and II), and ADS-B with display capability. The updated AC also discusses the information provided by each of these systems and stresses that they are intended as a supplement to, and not replacement for, the visual acquisition and avoidance of other aircraft.

Regarding the use of ADS-B as a tool to aid in a pilot's situational awareness, the AC states, in part, the following:

ADS-B is a system for air traffic surveillance. The FAA has mandated ADS-B Out by 2020 on all aircraft operating in current Mode C airspace (around Class B and C airspace and above 10,000 feet). With ADS-B, each aircraft broadcasts its own Global Positioning System (GPS) position along with other information like heading, ground track, groundspeed, and altitude (ADS-B Out). To see other aircraft, you must be equipped with ADS-B In to process the data signals.

The AC describes how other systems that actively interrogate other aircraft would continue to be useful beyond the FAA-mandated ADS-B Out requirement in 2020:

Active Traffic Systems. Active traffic systems (including TAS and TCAS) use Mode A, C, or S transponder interrogations to determine aircraft bearing and distance. Altitude is determined by reported Mode C altitude. After 2020, aircraft will be required to broadcast ADS-B Out and this data can be interpreted by aircraft with ADS-B In, but aircraft will still be required to have a Mode C or S transponder in airspace where it is currently required; thus, active traffic systems will continue to function. Most TAS systems will have ADS-B In capability available as an upgrade so these systems can interpret signals from either source.

Active Traffic Systems in an ADS-B Environment. Active traffic systems are valuable for three reasons in an ADS-B environment. First, even after January 1, 2020, not all aircraft will have ADS-B Out, particularly in airspace which does not require it. Thus, without an active traffic system, those unequipped aircraft would not display on a cockpit traffic display even if you had ADS-B In. Second, an active traffic system will display all aircraft independent of the type of ADS-B Out, since all aircraft will still be required to have a Mode C or Mode S transponder. Third, ADS-B is dependent on GPS signals, so during periods of poor satellite geometry or solar storms, GPS position and thus ADS-B could be disrupted and less reliable, meaning an active traffic system can act as a backup to ADS-B in the cockpit.

In 1977, the Massachusetts Institute of Technology published a report for the FAA, titled Air to Air Visual Acquisition Performance with Pilot Warning Instruments (PWI), which describes how PWI could be used to aid pilots in the visual acquisition task. These instruments would generally use some electronic means to detect and then present pilots with information about particular threats, focusing their attention to where it was most needed:

The primary intent of PWI is to improve the search performance of the pilot. The PWI alarm ensures that scanning will be given high priority when it is most critical and by directing the pilot's search to a particular sector, the area to be scanned is greatly reduced. Another effect discovered in the IPC [Intermittent Positive Control]/PWI flight tests is the tendency of PWI to reduce the effect of airframe obstruction. Not only do pilots shift their positions within the cockpit in an effort to scan a threat sector, but many pilots alter the aircraft attitude in order to achieve an unobstructed view in the threat direction. Thus, PWI favorably affects the first two elements of acquisition (search and field of view). It does not alter detectability or speed of approach in any direct way.

Research into pilots' performance in the visual acquisition task conducted in support of the report found that "Unaided visual acquisition is effective as a means of separation assurance only for lower values of crossing angles (relative heading). At higher values of crossing angle the increased closure speeds and decreased visible areas reduce performance considerably."

In our report regarding a midair collision over the Hudson River (Midair Collision Over Hudson River, Piper PA-32R-300, N71MC, and Eurocopter AS350BA, N401LH, Near Hoboken, New Jersey, August 8, 2009, AAR-10/05), the NTSB stated, in part, the following;

There are inherent limitations associated with the see-and-avoid concept as the primary method for aircraft separation. These limitations include a pilot's ability to perform systematic scans, competing operational task demands, environmental factors, and blind spots associated with an aircraft's structure. Traffic advisory systems can provide pilots with additional information to facilitate pilot efforts to maintain awareness of and visual contact with nearby aircraft to reduce the likelihood of a collision.

Most traffic advisory systems, including TIS [traffic information service], have visual displays of nearby traffic that show an aircraft's position or distance, direction of travel, and relative altitude and indicate whether the aircraft is climbing or descending. The NTSB recognizes that incorporating a visual traffic display into a pilot's scan could increase workload, but any increase in workload would be offset by the safety benefits resulting from the augmented awareness of other aircraft operating in the area, as displayed by the traffic system. However, these safety benefits are not a substitute for the see-and-avoid concept. In fact, Garmin guidance stated that TIS does not relieve pilots of their responsibility to see and avoid other aircraft. Thus, pilots are responsible for paying attention to the position of other aircraft for collision avoidance and not relying solely on a traffic advisory system for aircraft position information.

Joseph Elman Johnson: http://registry.faa.gov/N3601V

NTSB Identification: ERA15FA259A
14 CFR Part 91: General Aviation
Accident occurred Tuesday, July 07, 2015 in Moncks Corner, SC
Aircraft: CESSNA 150M, registration: N3601V
Injuries: 2 Fatal, 1 Uninjured.

NTSB Identification: ERA15FA259B
14 CFR Armed Forces
Accident occurred Tuesday, July 07, 2015 in Moncks Corner, SC
Aircraft: LOCKHEED-MARTIN F-16CM, registration: 96-0085
Injuries: 2 Fatal, 1 Uninjured.


This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

On July 7, 2015, at 1100 eastern daylight time, a Cessna 150M, N3601V, and a Lockheed-Martin F-16CM, operated by the U.S. Air Force (USAF), collided in midair near Moncks Corner, South Carolina. The Cessna was destroyed during the collision, and both the private pilot and passenger were fatally injured. The damaged F-16 continued to fly for an additional 3 minutes until the pilot activated the airplane's ejection system. The F-16 was destroyed following the subsequent collision with terrain and post-impact fire, while the pilot landed safely and was uninjured. Visual meteorological conditions prevailed, and no flight plan was filed for the Cessna, while the F-16 was operating on an instrument flight rules flight plan. The Cessna departed from Berkley County Airport (MKS), Moncks Corner, South Carolina, at 1057, and was destined for Grand Strand Airport (CRE), North Myrtle Beach, South Carolina; the personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The F-16 had departed from Shaw Air Force Base (SSC), Sumter, South Carolina about 1020.

According to the USAF, after departing from SSC, the F-16 proceeded to Myrtle Beach International Airport (MYR), Myrtle Beach, South Carolina, where the pilot conducted two practice instrument approaches before continuing the flight to Charleston Air Force Base/International Airport (CHS), Charleston, South Carolina. According to preliminary air traffic control (ATC) radar and voice communication data provided by the Federal Aviation Administration (FAA), the F-16 pilot contacted the approach controller at CHS about 1052 and requested to perform a practice tactical air navigation system (TACAN) instrument approach to runway 15. The controller subsequently instructed the F-16 pilot to fly a heading of 260 degrees to intercept the final approach course. At 1055, the controller instructed the F-16 pilot to descend from his present altitude of 6,000 feet to 1,600 feet. About that time, the F-16 was located about 34 nautical miles northeast of CHS.

At 1057:41, a radar target displaying a visual flight rules transponder code of 1200, and later correlated to be the accident Cessna, appeared in the vicinity of the departure end of runway 23 at MKS, at an indicated altitude of 200 feet. The Cessna continued its climb, and began tracking generally southeast over the next 3 minutes. For the duration of its flight, the pilot of the Cessna did not contact CHS approach control, nor was he required to do so. At 1100:18, the controller advised the pilot of the F-16, "traffic 12 o'clock, 2 miles, opposite direction, 1,200 [feet altitude] indicated, type unknown." The F-16 pilot responded and advised the controller that he was "looking" for the traffic. At 1100:26, the controller advised the F-16 pilot, "turn left heading 180 if you don't have that traffic in sight." The pilot responded by asking, "confirm 2 miles?" Eight seconds later, the controller stated, "if you don't have that traffic in sight turn left heading 180 immediately." Over the next 18 seconds, the track of the F-16 began turning southerly.

At 1100:49, the radar target of the F-16 was located 1/2 nautical mile northeast of the Cessna, at an indicated altitude of 1,500 feet, and was on an approximate track of 215 degrees. At that time, the Cessna reported an indicated altitude of 1,400 feet, and was established on an approximate track of 110 degrees. At 1100:52 the controller advised the F-16 pilot, "traffic passing below you 1,400 feet." At 1100:54, the radar reported altitude of the F-16 remained at 1,500 feet and no valid altitude information was returned for the radar target associated with the Cessna. At that point the targets were laterally separated by about 1,000 feet. No further radar targets were received from the Cessna, and the next radar target for the F-16 was not received until 1101:13. At 1101:19, the F-16 pilot transmitted a distress call, and no subsequent transmissions were received. Air traffic control radar continued to track the F-16 as it proceeded on a roughly southerly track, and after descending to an indicated altitude of 300 feet, radar contact was lost at 1103:17 in the vicinity of the F-16 crash site.

The wreckage of the Cessna was recovered in the vicinity of its last observed radar target, over the west branch of the Cooper River. Components from both airplanes were spread over an area to the north and west of that point, extending for approximately 1,200 feet. The largest portions of the Cessna's airframe included a relatively intact portion of the fuselage aft of the main landing gear, and the separate left and right wings, all of which were within 500 feet northwest of the airplane's final radar-observed position. Portions of the cabin interior, instrument panel, fuel system, and engine firewall were found distributed throughout the site. The engine, propeller, and nose landing gear assembly were not recovered. The lower aft engine cowling of the F-16 was also recovered in the immediate vicinity of the Cessna's aft fuselage, while the F-16's engine augmenter was recovered about 1,500 feet southwest. Small pieces of the F-16's airframe were also distributed throughout the accident site.

Both of the Cessna's wings displayed uniform leading edge crush damage throughout their spans that was oriented aft and upward. Paint transfer and rub markings oriented in a direction from the airplane's left to right were observed on the upper forward surfaces of both wings. Both fuel tanks were ruptured, and evidence of heat damage and paint blistering were observed on the upper surface of the right wing. Flight control continuity was traced through overload-type cable separations from the cabin area to each flight control surface. Measurement of the pitch trim actuator showed a position consistent with a 3 to 4-degree deflection of the tab in the nose down direction, and measurement of the flap actuator showed a position consistent with the flaps having been in the retracted position.

The F-16 wreckage site was located about 6 nautical miles south of the Cessna wreckage site. The F-16 wreckage path was about 700 feet long and oriented roughly 215 degrees, with portions of the airframe distributed along the wreckage path. The wreckage displayed significant ground impact and post-impact fire-related damage. A crash-survivable memory unit (CSMU) was recovered from the wreckage, and the digital flight control system seat data recorder (DFLCS SDR) was recovered from the airplane's ejection seat. Both memory units were forwarded to the airframe manufacturer for data extraction under the supervision of an NTSB Vehicle Recorder Specialist.

The weather conditions reported at MKS at 1055 included calm winds, 10 statute miles visibility, scattered clouds at 2,600 feet agl, a temperature of 30 degrees C, a dew point of 22 degrees C, and an altimeter setting of 30.15 inches of mercury.

FAA Flight Standards District Office:  FAA West Columbia FSDO-13

Any witnesses should email witness@ntsb.gov, and any friends and family who want to contact investigators about the accident should email assistance@ntsb.gov .

MONCKS CORNER, S.C. (WCIV) -- Berkeley County dispatchers fielded nearly a dozen calls from witnesses moments after an F-16 crashed into a Cessna C-150 on July 7th. 

Berkeley County officials released the calls Friday from residents who either witnessed the mid-air collision or saw the debris raining from the sky. 

"I just saw two planes collide in the air," said the first caller, a man from Lewisfield Plantation. "One of them dropped, I think, in our rice field." 

The man and his son were navigating the wooded terrain and water, looking for survivors. 

"I'm trying to get to the plane now but it's tough," he said. "There was like a military plane, a jet plane. It came over really fast and hit a little plane. The little plane dropped out of the sky."

Authorities say father and son Michael and Joseph Johnson, who were flying the small plane to Myrtle Beach, died in the crash. The pilot of the F-16 safely ejected from the jet.  

The caller said the jet plane was flying low when the planes collided, erupting into thick black smoke.

"It came over flying really low and pretty fast and ran into the other one," he said of the jet.

The caller gave the phone to his young son as he continued to search the water for the plane. 

"The black smoke's gone. We just see pieces of it everywhere," the son said. 

They told the dispatcher that the plane was underwater in a pond in the woods. 

"I see a shoe floating in the water," the boy said. "We can see what looks like a piece of a body. There's body parts. Oh God, there's more." 

A second caller said he was on the Cooper River when he saw the jet, mistaking the debris for "pretend bombs."

"There was a jet that flew over the Cooper River. He dropped, well it looked like he was dropping pretend bombs but he damned near hit me. Those bombs were coming right down on my head. He missed me maybe by 100 yards," he said. 

Part of the jet's afterburner landed in a campground on McCray Drive. 

"Two planes just collided and part of the pieces are here in the campground," said the third caller, a woman at the campground. "We don't really know what's going on. It just happened. There's a big explosion ... There are just pieces everywhere."

A number of people called to make sure dispatchers already knew about the crash. 

The tenth caller said she was sitting in her yard when she saw it happen.

"We heard what we thought was a sonic boom to our left," she said. "And then that fighter jet came right over our heads and turned, gently, you know more to the Cooper River and then we heard what sounded like another boom."

102 photos: http://www.abcnews4.com
  


Joseph Johnson, age 30, of Moncks Corner was the pilot of the Cessna 150M that collided with the F-16C Fighting Falcon. The Cessna 150M carried one passenger, Johnson’s father, Michael Johnson, age 68.
~


MONCKS CORNER, S.C. (WCIV) -- Family and friends gathered on Saturday afternoon to remember the father and son who were killed when their small plane collided with an F-16 over the Cooper River in Moncks Corner earlier this week.

Michael and Joseph Johnson both died when their Cessna 150 collided with an F-16 fighter jet.

“If they had to choose a way to go it would be in the air,” said Jean Paul, who used to fly with the two.

“Joe loved to fly and the same with his dad Mike,” said William Finn, who was their flight instructor for a year. “They would come to the airport several times a week, Joe really had a passion for it, he took up after his father.”

Their funerals were held at First Baptist Church in Moncks Corner.

“Joe was such a good guy,” said Walt Schuler, a friend. “Everybody loved him, every time he walked into a room it was like sunshine he just lit up everything.”

“We used to call Joe Scooby Doo because of his loving playful personality,” said Paul. “He also was good at like everything -- pilot, basketball, I mean anything you can think of he was good at. He wasn’t a jack of all trades; he was a master at all trades.”

Michael Johnson used to serve in the military during Vietnam.

“People like him are unsung heroes,” said Finn. “I thank him for his service, and am thankful just to know him. He and his son remind me of my family, we have three generations of pilots and we are close knit.”

As they mourn the loss of two people they love, they send their prayers to the family.

“I can’t imagine what Joe’s mom and brother are going through, to lose both of them at the same time in the blink of an eye that has to be rough. I send blessings to them, and pray for better days until one day we see them on the other side.”



‘Freak’ midair collision should serve as a warning as Charleston’s skies get busier 


 The skies over Charleston have become a beehive of activity.

Nearly 140 commercial flights a day go through the international airport.

Heavy-duty C-17 cargo jets fly around the world out of Joint Base Charleston.

And hundreds of smaller civilian planes take off from here or cross through, heading in different directions.

With all signs pointing to the local hubs getting busier, last week’s fatal collision between an F-16 Air Force jet and a private Cessna over Berkeley County might be a warning of potential hazards on the horizon.

How will the region react?

Charleston County Aviation Authority Executive Director Paul Campbell called Tuesday’s collision “a freak accident.”

He pointed out that the incident occurred between a small airplane that took off from the Berkeley County Airport and a fighter jet that took off from Shaw Air Force Base in Sumter — not Charleston International Airport or Joint Base Charleston.

“As long as the FAA tower controls the air space and limits what can happen, it can be done safely,” Campbell said of flight in the area.

He said there is plenty of room to add more planes in the Charleston commercial market, where several airlines have recently added new service to meet the growing demand.

“In the overall scheme of things, it’s not that much more. If you look at Charleston compared to the big airports, we are a drop in the bucket,” he said.

The Federal Aviation Administration declined to comment about air safety over Charleston, saying it was part of the probe into Tuesday’s midair crash.

FAA spokesman Jim Peters said the equipment used at the control tower at Charleston International is the same as that used throughout the national airspace system, meaning it should be up to date.

The collision remains under investigation, but it occurred in clear weather over a sparsely populated part of the county. The two people killed were Mike Johnson, 68, and Joe Johnson, 30, a father and son from Berkeley County flying in the Cessna. Pilot Maj. Aaron Johnson successfully ejected out of the F-16C fighter jet after the crash. The Cessna was not carrying a black box, but the F-16 had a flight data recorder. Both planes had working transponders, which send traffic controllers information about their positions.

Charleston isn’t unique in terms of having civilian, commercial and military aircraft in the same air box. Seattle, San Antonio and Washington are just a few with overlap. But there are those who say it should automatically mean heightened attention to safety.

“It’s a bad mix sometimes with military and civilian aircraft operating in the same area,” said Rick Parker, a flight instructor with Coastal Aviation in Mount Pleasant.

He said there are certain routes military aircraft fly for training missions and small aircraft pilots should check to see if any of those routes are active before taking off.

While he said the skies are busy, Parker hasn’t seen many problems. He added that it is rare to see a civilian aircraft and a military jet cross paths like the two ill-fated planes did Tuesday.

“There was a breakdown there somewhere,” he said.

Experts say the fact a military plane was involved in the accident here makes the event unique.

George Perry, a senior vice president with Aircraft Owners and Pilots Association, said it’s been 10 years since the last midair collision involving a private and military plane.

Generally “midair collisions are extremely rare,” he said. “There’s only a handful every year, and that’s across the country.”

Military accidents “are almost unheard of,” he said.

Officials at Joint Base Charleston declined to make anyone available for an interview on their safety measures but in an email said training, maintenance and quality assurance remains a priority.

Berkeley County Supervisor Bill Peagler declined to speak about the safety in the skies over the Charleston area, pending the outcome of the crash investigation by the National Transportation Safety Board.

“I was as shocked as anyone else,” he said when he heard of the crash, but he emphasized the county was preparing to put another full-time worker at the small airfield and prepare the runway for larger aircraft before Tuesday’s incident.

“Air traffic in the tri-county area is going to increase because of the growth (in population) and more industry,” he said. “That’s going to put more of a burden on smaller airports. We are trying to make more space for bigger airplanes to arrive here.”

He believes the airport’s 5,000-foot runway should be extended and a power line at one end needs to be moved so larger aircraft can use the airfield southwest of Moncks Corner.

The Charleston area has multiple small or executive airports and airfields currently in operation, including on Johns Island and in North Charleston, Mount Pleasant, Jedburg and Moncks Corner. Accidents out of these smaller airfields have mostly involved pilot or mechanical error, not collisions.

Three recent small plane crashes with fatalities include:

The October 2009 crash of a twin-engine 1976 Piper PA-23 just seconds after leaving the runway at the Dorchester County Airport that killed four.

The June 2013 crash of a 1977 Rockwell International 690B into heavy woods near McClellanville. Two people on board were killed after leaving Johns Island Executive Airport for a training flight moments before.

The August 2014 crash at Mount Pleasant Regional Airport that killed two on board a Cessna 150M shortly after takeoff. It, too, was called a training flight.

North Charleston Mayor Keith Summey, whose city surrounds the Air Force base and Charleston International Airport, said a possible aircraft disaster isn’t something that keeps him up at night.

He noted that cities like New York and Washington manage with more flights coming in and out, of all kinds, and still maintain good performance records.

Summey, too, termed the Berkeley crash an apparent “freak accident” that isn’t part of an underlying problem.

“This one was, I think, unfortunate timing,” he said.

Source:  http://www.postandcourier.com

Mike E. Johnson | 1947 - 2015 | Obituary

Born: May 21, 1947
Died: July 07, 2015


Michael Elman “Mike” Johnson, 68, of Pinopolis, SC, co-owner and operator of J & W Construction, died Tuesday morning in Berkeley County.

His memorial service will be 4:00 PM Saturday afternoon, July 11, 2015, in the First Baptist Church, Moncks Corner, directed by Dial-Murray Funeral Home, Moncks Corner. The family will receive friends at the CHURCH from 2:00 PM until the hour of service on Saturday. In lieu of flowers, the family requests memorials be made to the First Baptist Church, 112 E Main St., Moncks Corner, SC 29461, to the American Cancer Society, 5900 Core Rd., Ste. 504, N. Charleston, SC 29406, or to the Salvation Army, 203 White St., Moncks Corner, SC 29461.


Mr. Johnson was born May 21, 1947, in West Point, NY, a son of Luther Johnson and Conchita Aunon Johnson. He was a 1969 graduate of The Citadel where he also played baseball. Mr. Johnson served in the Army Airborne during Vietnam, and retired as a Lieutenant Colonel from the Army Reserves. He was a former administrator for the Berkeley County school system from which he retired as a vocational instructor. Mr. Johnson was also a pilot, mechanic, and former skydiver. In his spare time, he enjoyed inventing things for which he obtained patents. Mr. Johnson was of the Catholic faith and was preceded in death by a brother, Jim Johnson.

Surviving are, his wife, Lisa Turchin Johnson; a son, Patrick M. Johnson and his wife, Caitlin, of Beaufort; a sister, Connie Stallworth of Ft. Worth, TX; two brothers, Danny Johnson of Mt. Pleasant, and Pat Johnson of Ft. Walton Beach, FL; a granddaughter, Jolie Johnson, and a grandson, Luther Joseph Michael Johnson, whom is soon to be born.

Obituary and Guest Book:  http://www.dial-murrayfuneralhome.com

Joe E. Johnson | 1984 - 2015 | Obituary

Born: August 10, 1984

Died: July 07, 2015


Joseph Elman “Joe” Johnson, 30, of Summerville, SC, a real estate appraiser for Patriot Appraisals, died Tuesday morning in Berkeley County.

His memorial service will be 4:00 PM Saturday afternoon, July 11, 2015, in the First Baptist Church, Moncks Corner, directed by Dial-Murray Funeral Home, Moncks Corner. The family will receive friends at the CHURCH from 2:00 PM until the hour of service on Saturday. In lieu of flowers, the family requests memorials be made to the First Baptist Church, 112 E Main St., Moncks Corner, SC 29461, to the American Cancer Society, 5900 Core Rd., Ste. 504, N. Charleston, SC 29406, or to the Salvation Army, 203 White St., Moncks Corner, SC 29461.

Joe was born August 10, 1984, in Charleston, SC, a son of Michael E. Johnson and Lisa Turchin Johnson. He was a graduate of Berkeley High School, where he was a former “All Region” pitcher for the baseball team. He attended The Citadel and played baseball, as his father did before him, and then went on to Louisburg College from which he received his associate’s degree and was an “All Conference” pitcher. After graduation, Joe was drafted by the Atlanta Braves, and was still playing baseball in a local men’s league.

He was also a licensed pilot and was currently logging hours to become a commercial pilot while working as a member of the ground crew for Delta Airlines. Joe loved his RC model planes and working out, but most of all, he loved his daughter and spending time with her.

Surviving are, his daughter, Jolie Johnson of Greenville; his mother of Pinopolis; a brother, Patrick M. Johnson and his wife, Caitlin, of Beaufort; and a nephew, Luther Joseph Michael Johnson, soon to be born.

Obituary and Guest Book: http://www.dial-murrayfuneralhome.com


MONCKS CORNER, SC – Berkeley County Coroner Bill Salisbury says that the body of 30-year-old Joseph Johnson of Moncks Corner was located by divers at 4:30 pm on Wednesday, July 8. Mr. Johnson was the missing pilot from the plane collision involving an F-16 and a Cessna 150M.

An autopsy of both bodies will be done on Thursday, July 9. His father, Michael Johnson, 68, was the passenger in the Cessna that crashed and killed both of them. Michael Johnson’s body was found Wednesday, July 7. At that time, they had found Joseph Johnson’s wallet, but not his body.

Funeral arrangements have been made for Michael and Joseph Johnson. A memorial service will be held at 4:00 PM on Saturday, July 11, 2015 in the First Baptist Church (112 East Main Street in Moncks Corner).

The family will receive friends at the church on Saturday from 2:00 PM until the hour of service. In lieu of flowers, the family requests memorials be made to the First Baptist Church (112 East Main Street, Moncks Corner, SC 29461), to the American Cancer Society (5900 Core Road, Suite 504, North Charleston, SC 29406), or to the Salvation Army (203 White Street, Moncks Corner, SC 29461)

The arrangements are being directed by Dial-Murray Funeral Home. Any questions about the services should be made directly to Dial-Murray.




Berkeley County Rescue Squad and teams from other agencies searched Wednesday the site of a crash between a fighter plane and a small two-seat aircraft. A father and son from Moncks Corner were killed in the crash. 



MONCKS CORNER — Berkeley County father and son Mike and Joe Johnson boarded a single-engine, two-seat Cessna plane Tuesday morning with plans of spending the summer day in Myrtle Beach.

The morning ended, instead, in tragedy when their plane collided midair with a F-16C jet from Shaw Air Force Base. Both father, 68, and son, the Cessna’s 30-year-old pilot, were killed in the wreckage over Lewisfield Plantation, Berkeley County Coroner Bill Salisbury announced Wednesday in a news conference.

The deadly collision, considered a rare one by at least one investigator with the National Transportation Safety Board, left authorities piecing together a string of events and sifting through data to determine what went wrong and how to prevent it from happening again.

The answer to those questions, however, are likely months away.

Authorities intend to question the jet’s pilot, Air Force Maj. Aaron Johnson, who parachuted to safety, NTSB investigator Dennis Diaz said during Wednesday’s news conference.

Aaron Johnson was said to be on a solo mission to practice instrument-assisted approaches at Charleston Air Force Base and intended to return to Shaw that day. He was picked up at Medway Plantation shortly after the collision.

Rescue and dive teams recovered Mike Johnson’s body along the Cooper River on Wednesday, not far from the crash site, Salisbury said. A search continued throughout the day for Joe Johnson’s remains without success, he said.

“I want to caution you that we are in the very early phases of our investigation,” Diaz said of what was known so far about the collision. He added that the agency’s immediate goal was to preserve evidence.

Investigators planned to focus on the Cessna’s crash site on Wednesday and the F-16 crash site Thursday, he said.

The Cessna was not carrying a black box, but the F-16 had a flight data recorder, he said. Both planes had working transponders that send traffic controllers information about position. Diaz also will listen to the audio between the jet pilot and air-traffic control, he said.

The Cessna’s pilot also was in contact by radio with the Berkeley County Airport, where it had launched minutes before the collision.

“Both aircraft had operable transponders that basically report back to the radar site the aircraft’s location and altitude,” Diaz said. “I know the data’s there, and we’re going to be reviewing it.”

A preliminary report should be available within the next two weeks, Diaz said, with additional reports, and ultimately a ruling on probable cause, to follow in coming months, Diaz said.

A goal of the investigation is to make safety recommendations to prevent a similar occurrence, he said. That includes checking whether this accident was similar to previous ones.

Collisions between military jets and private planes are rare. Diaz said he could recall only one other such crash in 1999 in Florida.

“That is the unique aspect of it,” he said.

‘A foot and a half away from death’

Debris from the wreckage was scattered over an 8-mile stretch throughout rural Berkeley County.

No injuries were reported on the ground, but authorities fielded one report of damage when the jet’s falling engine landed within a cluster of residential campers that sit beneath a bay of trees on McCrae Drive. The Cooper River calmly flows just beyond the property’s edge.

“I heard a big boom. Then, 30 seconds later, another boom,” said Jeremy Rollings, 32, who was home sleeping moments before the collision.

A panic quickly swept over his neighbors, many of whom responded to the crash with screams of “Oh my God, oh my God,” Rollings said.

He too was shaken, he said, and fixed his on eyes on the skyline for fear of being struck by remaining debris.

Rollings used a cellphone to record footage of part of the engine resting against the trailer of his neighbor, 26-year-old Will Cecil. Authorities responded some time later, he said as his fingers flipped through additional footage of investigators combing through the area to collect the remnants and question witnesses.

Cecil was away from home when the collision occurred. Talks with neighbors indicated that the part landed with force akin to an earthquake, he said.

“The ground actually shook on them. That’s what they told me,” Cecil said.

The impact damaged his trailer’s plumbing system and splintered the home’s siding nearest to his bedroom.

If he had been home, he said, he or his 7-month-old daughter could have been wounded, or worse.

“Looking at this, I’m about a foot and a half away from death,” Cecil said examining the damage.

Despite the close call, Cecil said he wishes he would have been home Tuesday night. He returned to the trailer Wednesday morning to find it ransacked and burglarized, he said. He suspects the impact knocked open his front door, enabling a thief to sneak inside.

He’s working with an attorney to seek compensation for the damages.

Father and son

Mike Johnson, the father, was a former teacher and carpenter. His son was a passionate baseball player with an ambition of becoming an airline pilot.

The two lived at the same residence on a quiet street in Pinopolis with their wife and mother, Lisa Johnson, according to public records. Another son, Patrick Johnson, lives in Columbia, friends said.

Mike Johnson is a 1969 graduate of The Citadel, according to his classmate Pat Dougherty of Riva, Md. Doughtery said Johnson served as best man in his wedding in 1970.

Officials at The Citadel confirmed that they have Michael Johnson listed as a 1969 graduate.

Johnson served in Vietnam with the 101st Airborne Division Pathfinders and retired as a lieutenant colonel in the Army Reserve. Johnson and Doughtery served together in the 82nd Airborne at Fort Bragg from 1969-70 and in the 101st Pathfinders in Vietnam in 1971, Doughtery said.

Johnson also earned a master’s degree from The Citadel, he said.

Joe Johnson graduated from Berkeley High School in 2003 and then attended The Citadel from 2003 to May 2005 and later Louisburg College in North Carolina. He was a member of The Citadel baseball team for the 2004 and 2005 seasons. He was selected by the Atlanta Braves in the 13th round of the 2006 Major League Baseball draft.

Citadel head baseball coach Fred Jordan praised his pitching abilities, adding that “Joe’s impact on our program extended beyond his statistics, and we are deeply saddened by his passing.”

The younger Johnson “followed in his father’s footsteps attending The Citadel and was a fine young man who was upbeat and fun to be around.”

Childhood friends in Moncks Corner recalled his love of baseball.

“He was a very good pitcher, and threw the ball pretty hard,” said city of Charleston police officer Trent Weathers, a 2006 Citadel graduate who played with Johnson in youth ball in Moncks Corner, at Berkeley High and The Citadel. “He was that guy everybody wanted to be on their team to be the starting pitcher. He was a very outgoing, happy person. He loved the game of baseball and was just a pleasure to be around.”

Dwayne Kitts, former recreation director in Moncks Corner and a scout for the Braves for 26 years, knew Joe since he was 5 years old.

“He was the kind of kid who lit up a room when he walked in,” he said. “A good looking kid, a great personality. He liked to play jokes and got into mischievous trouble here and there, but nothing major.”

The 6-4 right-hander pitched in 35 games over two seasons in the minor leagues, including stints with the Danville Braves and the Rome Braves. He also was a member of the North Charleston Astros, a team in the Charleston Men’s Adult Baseball League, and played in a league game Monday night at Ashley Ridge High School.

Thomas Levander, the Astros’ player-manager, called the accident “shocking news.”

“Joe was a great guy and a great teammate,” Levander said. “He was the oldest player on our team and he just loved being out there. He had a great attitude and always had a smile on his face. He is the most down to earth person I ever met and it’s sad that his life has been cut so short.”

David Beckley, an assistant baseball coach at The Citadel, was the head coach at Berkeley High School when Joe Johnson played there.

“Joe was a great kid — a really hard worker who was really kind of a late bloomer,” Beckley said. “He had to work hard for everything he got, and he loved the game. ... He was a great person and came from a great family. I personally am very saddened by this tragic news, and my prayers are with his family.”

Joe Johnson, a student pilot, recently had worked for Delta with the goal of flying for an airline. He was recognized by the Federal Aviation Administration in its FAA Airmen Certification Database, according to the Aviation Business Gazette.

He was the registered owner of the Cessna, whose model is listed in FAA records as an 150M. Earlier reports stated that the plane was a 150C.

Susan Gehlmann, a neighbor of Johnsons in Pinopolis for about 17 years, said the Johnsons were a nice family.

Mike Johnson taught carpentry in the Berkeley County School District, she said. He recently worked in construction.

Berkeley County School District Officials did not immediately respond to a request for information on Johnson.

Kitts said brought some of his vocation students to the Moncks Corner ballpark to do volunteer repair work.

The family has recently had another tragedy, according to the St. Joseph (Mo.) News Press. Mike Johnson’s brother, James Johnson, 72, and his wife, Beverly, were found shot to death at their St. Joseph residence on Saturday. A 16-year-old has been charged with two counts of second degree murder in their deaths.

The story said Johnson also has an older sister, Connie Stallworth.

Dougherty said another brother, G. Patrick Johnson, was a member of The Citadel Class of 1966.

The family declined to make a statement at this time, Berkeley County spokesman Michael Mule said Wednesday.

Source:  http://www.postandcourier.com

Jeremy Bass 
"The important part for the aviation community is to learn from that, and grow from that, to mitigate future accidents, and for the public to understand that we as aviators do take from that .... we learn from that and we grow," aviator Jeremy Bass said.
~



MYRTLE BEACH, SC (WMBF) - Officials say the plane that crashed to the ground Tuesday afternoon was headed to the Myrtle Beach area carrying a Moncks Corner man and his father.

Officials are still searching for the pilot, 30-year-old Joseph Johnson, but they did find the body of his passenger, and father, 68-year-old Michael Johnson, following the mid-air crash that brought an F-16 and a small plane crashing to the ground Tuesday afternoon.

In Wednesday's press conference regarding the crash, officials say the 68-year-old was found by an SCDNR boat. His son, Joseph Johnson, was the one flying the private plane that collided with the military plane. Right now a helicopter, drones, and dive teams are searching for the pilot. As the NTSB team continues the investigation into what caused the crash.

Myrtle Beach aviator Jeremy Bass says there is a very small chance the pair would have seen the military plane coming, meaning there would be little to no time to respond.

"If he was cruising, he would have probably only been flying 80 to 90 miles per hour, maybe 100 miles per hour at the most, versus an F-16 is going to be traveling somewhere between 250 to 300 knots - upwards of 300 miles per hour," Bass explained.

Bass says because of that difference in speeds, and the fact that the F-16 is built to be sleek, it probably went from being a speck in the sky to a serious collision.

"It seems like there is an infinite amount of sky. How can that happen especially when you do have air traffic controllers watching your back, calling traffic, that type of thing? It's just one of those odd and unfortunate instances," Bass said.

Bass says because Joseph and Michael Johnson were flying a small, private plane, it's very possible they didn't submit a flight plan or speak with anyone on a radio before take off.

"If they would've spoken to someone, it was before they entered Myrtle Beach's air space," Bass explained. "They would have spoken to the air traffic controllers here, but they could have flown all the way here without taking to anybody," Bass explained.

Bass says this flight would have been perfectly legal. He explained as long as conditions are clear, and there are no major cities around the airports, many pilots depart and land as they please, and it's likely a transmitter box wouldn't have been on in the plane either.

"It pings back and forth and it tells air traffic control where that plane is physically located, how high they're flying, what altitude they are flying, they're not even required to have that," Bass said.

Bass explains this is because the two were flying in uncontrolled air space. Though he feels this is a tragic loss for the aviation community, Bass believes there is a lesson to be learned.

"The important part for the aviation community is to learn from that, and grow from that, to mitigate future accidents, and for the public to understand that we as aviators do take from that. we learn from that and we grow," Bass said.

Source:  http://www.wmbfnews.com



Joseph Johnson, left, is seen in this undated handout photo.




Joseph Johnson
~


MONCKS CORNER, S.C. (WCIV) -- Federal and local officials called the search for Joseph Johnson a "priority" at a news conference Wednesday.


“We have divers, helicopters and drones mapping the area and taking pictures. We’re reviewing and doing all we can think of to locate [Joe Johnson],” Berkeley County Coroner Bill Salisbury said.


Officials said Joe Johnson, 30, was piloting a small plane when it collided mid-air with an F-16 fighter jet on Tuesday. Salisbury said Joe's father Michael Johnson, 68, was a passenger in the small Cessna aircraft. 


Friends said Joe had recently become passionate about flying.


“He had a desire to be a commercial pilot," his former Berkeley High School baseball coast Landy Cox said.


Cox said Joe Johnson was also passionate about baseball. The former Berkeley High School standout went on to pitch in college and for a Braves minor league team.


"He signed a Division I scholarship and without his injury, would've played Major League Baseball," Cox said. "He was a tremendous athlete. Everything he did, Joe was successful. What stands out the most was the smile from ear to ear. He enjoyed being around people. When you walked away from Joe, you had a warm feeling. His presence made you feel better.”


Cox recalled one of his favorite memories of Joe Johnson pitching a one-hit game against Summerville High School in 2003. Summerville went on to win the state championship, he said.


Cox also said Joe’s father Michael Johnson was always at the field to see his son.


"He was always involved in Joe’s life. Whatever Joe did, he was there supporting him. It didn't shock me at all they were together in this tragedy," Cox said.


Fellow Moncks Corner native James Murrell also shared memories about his friend.


“He was convinced that he could accomplish what others wouldn’t dare try. If you were to look in just about any dictionary for the word ‘honor,’ I wouldn’t be surprised if Mike Johnson’s face wouldn’t be published right alongside it," he wrote in a text message.


Murrell said he and his friends affectionately called Michael Johnson "Captain America."


Fred Jordan, The Citadel's head baseball coach, said Wednesday evening that the university was mourning for the former cadet and student-athlete. 


"This is such a tragedy, and we are hurting for Joe’s family. Joe followed in his father’s footsteps attending The Citadel and was a fine young man who was upbeat and fun to be around," said Jordan. 


"On the mound, he had the ability to throw hard and continued to work toward his goal of being a professional pitcher, which he reached when he was drafted by the Atlanta Braves.  Joe’s impact on our program extended beyond his statistics, and we are deeply saddened by his passing."


Joe Johnson was a member of the Bulldog baseball team for the 2004 and 2005 seasons. He was a redshirt in 2004 and made one appearance in 2005 before transferring to another college and being drafted in the 13th round by the Atlanta Braves.


Source:  http://www.abcnews4.com




Berkeley County Coroner Bill Salisbury said in a noon news conference that the individuals occupying the Cessna single engine airplane involved in the mid-air collision with the F-16 Fighter Falcon over Moncks Corner on Tuesday, July 7, have been positively identified. 

Joseph Johnson, 30, was the pilot of the aircraft carrying he and a single passenger, his father, Michael Johnson, 68. Both men are from Moncks Corner.


Salisbury said the father and son were on their way to Myrtle Beach on a short day trip and planned to return that night.


The coroner also said the body of Michael Johnson had been recovered in the immediate area of the crash site on the Cooper River.

The search continues for Joseph Johnson with the help of several assisting agencies.

“This is a very active and ongoing search,” Salisbury said. “Our primary goal is to find this other person and return both home to their families.”

Salisbury said the wallet recovered near the crash site belonged to the pilot, Joseph Johnson.

The Cessna and the F-16 collided over the Cooper River shortly after 11 a.m. on Tuesday, July 7. The pilot of the fighter jet, Major Aaron Johnson, survived the wreck.

Berkeley County Sheriff Duane Lewis said his office had dispatched a diver team and a marine team to search the Cooper River for the remaining victim.

“The Berkeley County Sheriff’s Office has assumed a support position to assist the coroner in bringing this recovery mission to a successful conclusion,” Lewis said.

According to National Transportation Safety Board Air Safety Investigator Dennis Diaz, both aircraft had active radar. The F-16 had not encountered engine problems prior to the accident as had been speculation after the collision.

Since this is still an ongoing investigation, Diaz declined to comment on the specifics of the collision.

“We are in the very early phase of the investigation,” Diaz said. “Our primary purpose here is to document evidence found at two primary crash sites, the Cessna, located on the Cooper River near Lewisfield Plantation and the F-16 located approximately 10 miles from the first crash site.”

If citizens find any debris, they are asked to call 911.

The NTSB has taken the lead on the investigation with assistance being provided by the Federal Aviation Administration and the United States Air Force.

“We are in the process of collecting data which includes interviewing witnesses and interviewing the surviving pilot.”

Diaz said a preliminary report would be available in 5-to-10 business days but the investigation could take up to 12 months to complete.

“The most important reason why we’re here today is to investigate what happened and why, and make a safety recommendation to keep this from ever happening again.”

Source: http://www.berkeleyind.com



NTSB Air Safety Investigator Dennis Diaz said his main goal is to determine how and why this accident happened and to make safety recommendations to see it never happened again.




Berkeley County Sheriff Duane Lewis said his office would act in a support capacity to bring the recovery mission to a successful conclusion. 


Berkeley County Coroner Bill Salisbury said the body of Michael Johnson had been recovered in the immediate vicinity of the crash site. The search continues for Joseph Johnson, the pilot. 




 
Photo courtesy Capt. Joe Dennis
 While fishing on the Cooper River, charter fisherman Joe Dennis witnessed the collision between an F-16 fighter jet and a Cessna private plane. The smoke ball is from the crashing fighter jet.


Berkeley County, South Carolina   --   Local charter Capt. Joe Dennis was enjoying a leisurely Tuesday morning fishing along the Cooper River when he had to dodge a couple jettisoned fuel tanks.

The F-16C Fighting Falcon had just struck a private Cessna single prop airplane broadside and was going down fast.


“The F-16 had just hit another plane,” Dennis said. “They came over us and the pilot dropped his tanks. He ejected right after that. His three fuel tanks almost hit me.”


Dennis said the pilot checked the area before jettisoning his fuel tanks.


“He saw us down there and waited until he was clear before letting the tanks go,” Dennis said.


Emergency crews reported that the military pilot from Shaw Air Force Base had survived after ejecting from the damaged jet. A Berkeley County Emergency Medical Services crew said that he was alert and walking.


Dennis said the two aircraft collided between Lewisfield Plantation, property running along the banks of the upper Cooper River in Berkeley County off Old Highway 52 near Moncks Corner.


Dennis, also a professional photographer, was able to snap a photo from his cell phone of the smoke rising from the wreckage of the F-16 after it crashed.


“The Cessna went down into a watery rice field nearby while the jet veered leftward as if attempting to make it back to base,” Dennis said. “But the jet kept getting lower and lower in the sky.”


First responders found the private plane in about two feet of water.


Berkeley County Coroner Bill Salisbury said the F-16 had struck the Cessna broadside.


Debris was spread out over the plantation property and surrounding areas, according to Salisbury.


Source:  http://www.berkeleyind.com 


  

Deputies with Buchanan County Sheriff's Department were called to 8610 NE Hurlingen Rd. about 1:05 a.m. to check on the well-being of someone. The location is about nine miles outside of St. Joseph.



Plane collision marks 2nd deadly tragedy for family in a week

MONCKS CORNER, S.C. -- A collision between a small plane and an F-16 fighter jet that killed a father and son was the second fatal tragedy to strike their family in just four days, a relative told The Associated Press.

Authorities found the body of 68-year-old Michael Johnson, the passenger, in the Cooper River in a rural, sparsely populated area in South Carolina, Berkeley County Coroner Bill Salisbury said.

They are still searching the same area for the body of his son, 30-year-old Joseph Johnson, who was piloting the Cessna 150 when it was torn apart by its crash with the jet Tuesday.

On Saturday, Jim Johnson and his wife, Beverly -- Michael Johnson's brother and sister-in-law -- were found dead at their home in Missouri, said Connie Stallworth, the men's sister.

The couple's 16-year-old grandson has been charged with second-degree murder in their slayings, police said. His name has not been released because he is a juvenile, CBS affiliate KMOV-TV in St. Louis reported.

"It's unbelievable. There just aren't words to express it. I'm dumbfounded that it happened twice in a few days," Stallworth said.

NTSB investigator Dennis Diaz told reporters Wednesday that his first goal is to document the two crash sites, which are about 10 miles apart. He also said the F-16 pilot, who ejected safely, will be interviewed. However, that may not happen for several days.

Investigators will look at flight data recorders and interview witnesses, though that is expected to take months, Diaz said. He would not comment on the direction, speed or altitude at which either aircraft was traveling.

The jet's pilot, Maj. Aaron Johnson from the 55th Fighter Squadron, was taken to Joint Base Charleston's medical clinic for observation, officials from Shaw Air Force Base in Sumter said in a news release.

The jet crashed into woods around the privately owned Lewisfield Plantation, an estate dating to 1750.

"We heard the plane crash," said Leo Ramsey, who has worked at the plantation for about 30 years. "And then we took off from where I was at, I guess I was about a half-mile from it, when we saw a cloud of smoke."

Ramsey and two other workers found burning metal, splintered trees and a flaming crater where the jet had crash-landed, he said.

Col. Stephen Jost, commander of the 20th Fighter Squadron at Shaw Air Force Base, said Maj. Johnson was flying solo, practicing instrument approaches to a military base and was communicating with Charleston air traffic controllers.

Jost said he thought it was overcast at the time of the collision, but he was not aware of any weather-related problems.

CBS affiliate WCSC-TV in Charleston reported the crash happened just minutes after the father and son took off from the Berkeley County airport on a day trip to Myrtle Beach, according to an NTSB investigator. It wasn't clear if a flight plan had been filed, Berkeley County officials said.

F-16s from Shaw Air Force Base, about 35 miles east of Columbia, routinely fly training missions over eastern South Carolina and the Atlantic.

The Cessna 150 is a two-seat plane that typically weighs about 1,500 pounds when fully fueled. By comparison, an F-16 is about 50 feet long and weighs nearly 10 tons, not counting fuel or weapons. Jost said the F-16 was not carrying any live munitions at the time of the collision.

Story, video and comments: http://www.cbsnews.com