Wednesday, January 17, 2018

Cessna P210N Centurion, N6609P, registered to and operated by Stubblefield Construction Company: Fatal accident occurred May 18, 2016 near Sheridan Lake, Colorado

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

Analysis 

The private pilot was conducting a cross-country flight at 17,500 ft mean sea level (msl) while operating on a visual flight rules clearance. About 2 hours after takeoff, the pilot stated over the radio, "(unintelligible) I'm going down and I'm going down hard." Based on the pilot's speech, it became apparent to the controller that the pilot was experiencing some type of distress. The controller attempted to communicate with the pilot, concerned that he was possibly experiencing hypoxia, carbon monoxide exposure, or another medical condition that was affecting his speech and ability to control the airplane. Throughout the remainder of the flight, the controller provided numerous altimeter setting updates recommending that the pilot descent to a lower altitude in a continued effort to assist the pilot; however, the pilot did not acknowledge or reply to these requests. During three different radio transmissions, the pilot stated, "I can show you…" what the airplane can do. He also stated, "(unintelligible) guys want me to do Muller?", which is an aerobatic maneuver that involves a flat spin and recovery. (The airplane is not approved for aerobatics or spins.) Radar data indicated that the airplane entered a series of turns, climbs, and descents. The final recorded radar return indicated the airplane was about 9,200 ft msl. The airplane subsequently impacted a field in a flat spin. Examination of the airframe, engine, and airplane pressurization system revealed no mechanical malfunctions or anomalies that would have precluded normal operation.

Given that the airplane's descent did not improve the pilot's control of the airplane's heading or the quality of his communication with the controller, it is likely that the pilot's behavior was not the result of hypoxia.

Toxicology testing on the pilot was positive for ethanol at ranges between 0.247 gm/dl and 0.335 gm/dl, which is significantly higher than the legal limit of 0.040 gm/dl. While ethanol can be produced in tissues after death, this occurs by microbial action; and vitreous, where the levels were highest in specimens from the pilot, is typically a sterile fluid. In addition, an approximately half-full bottle of vodka was found in the wreckage, suggesting that the majority of the identified ethanol had been ingested. Further, the tested samples were positive for three additional impairing substances; diphenhydramine, lorazepam, and zolpidem. The pilot's impaired speech and behavior were most likely caused by the effects of high levels of alcohol along with effects from the three prescription medications, which likely led him to believe that he could perform maneuvers in the airplane that it was not capable of performing. 

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot's severe impairment from the combined effects of high levels of ingested alcohol as well as three impairing medications (zolpidem, lorazepam, and diphenhydramine), which resulted in his decision to attempt an aerobatic maneuver that the airplane was not approved for.

Findings

Aircraft
Angle of attack - Capability exceeded (Cause)
Aircraft capability - Capability exceeded (Cause)

Personnel issues
Alcohol - Pilot (Cause)
Prescription medication - Pilot (Cause)
Decision making/judgment - Pilot (Cause)
Incorrect action performance - Pilot (Cause)
Aircraft control - Pilot (Cause)

John Lee Stubblefield
John was an avid pilot and there was nothing that he loved more than being free in the skies.


The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Denver, Colorado
Textron; Wichita, Kansas
Continental Motors; Mobile, Alabama

Aviation Accident Factual Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

Stubblefield Construction Company

http://registry.faa.gov/N6609P

Location: Sheridan Lake, CO
Accident Number: CEN16FA188
Date & Time: 05/18/2016, 0901 MDT
Registration: N6609P
Aircraft: CESSNA P210N
Aircraft Damage: Substantial
Defining Event: Loss of control in flight
Injuries: 1 Fatal
Flight Conducted Under: Part 91: General Aviation - Personal 

HISTORY OF FLIGHT

On May 18, 2016, about 0901 mountain daylight time, a Cessna P210N, N6609P, sustained substantial damage when it impacted a field in a flat spin about 4 miles northeast of Sheridan Lake, Colorado. The pilot sustained fatal injuries. The airplane was registered to and operated by Stubblefield Construction Company under the provisions of the 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed for the flight, which departed at 0645 from Rock Springs-Sweetwater County Airport (RKS), Rock Springs, Wyoming, en route to Wiley Post Airport (PWA), Oklahoma City, Oklahoma.

Earlier that morning, about 0222, the pilot departed Nampa Municipal Airport, Nampa, Idaho, and flew to RKS, where he landed the airplane about 0442. A witness at RKS reported that the pilot had the airplane topped off with 68 gallons of fuel. He reported that the pilot slept in the pilot's lounge for about 1 hour before departing toward PWA.

After departing RKS, radar data from the Federal Aviation Administration (FAA) indicated that the airplane was flying on a southeast heading at 17,300 ft pressure altitude. About 0800, the pilot established visual flight rules flight following with the Denver, Colorado, Air Route Traffic Control Center, which provided the pilot with the current altimeter setting.

A transcript of the communications between the accident airplane and an air traffic controller indicated that, at 0842:36, the pilot transmitted, "(unintelligible) I'm going down and I'm going down hard."

It became apparent to the controller that the pilot was experiencing some type of distress. The controller attempted to communicate with the pilot, concerned that he was possibly experiencing hypoxia, carbon monoxide exposure, or another medical condition that was affecting his speech and ability to control the airplane. Throughout the remainder of the flight, the controller provided numerous altimeter setting updates in a continued effort to communicate with the pilot; however, the pilot did not acknowledge or reply to numerous controller requests. The controller made numerous recommendations to the pilot to descend to a lower altitude.

At 0846:23, the controller transmitted, "November six six zero nine papa suggest you descend to lower altitude at or below one two thousand uhh sounds like you might have an hypoxic situation."

The recorded radar data indicated that the airplane had maintained a straight-and-level flight track to the southeast at 17,300 ft pressure altitude until 0847. Then, the airplane entered a series of turns, climbs, and descents that ultimately put the airplane on a northerly course.

At 0853:16, the pilot transmitted, "I can show you what a p two ten can do." The radar data indicated that the airplane's altitude was about 11,700 ft pressure altitude at the time of the transmission.

At 0854:05, the pilot transmitted, "(unintelligible) guys want me to do Muller?" The radar data indicated that the airplane's altitude was about 12,275 ft pressure altitude at the time of the transmission.

At 0855:24, the pilot transmitted, "I can show you things this airplane can do." The radar data indicated that the airplane's altitude was about 10,600 ft pressure altitude at the time of the transmission.

At 0858:01, the pilot transmitted, "Let me show you what a (unintelligible) two ten can do." The radar data indicated that the airplane's altitude was about 10,950 ft pressure altitude at the time of the transmission.

At 0858:28, the controller transmitted, "November six six zero nine papa it's possible you're uhh uhh hypoxic and umm and carbon monoxide poisoning is going on if you could just open up that window maybe get some fresh air in that airplane November zero nine pop."

At 0900:30, the pilot's last radio transmission stated, "You got it watch the center watch it go." The last recorded radar return at 0900:32 indicated that the airplane's pressure altitude was about 9,200 ft. Subsequent attempts to contact the pilot were unsuccessful.

PERSONNEL INFORMATION

The 64-year-old pilot held a private pilot certificate with airplane single-engine land and instrument ratings. He held a third-class medical certificate issued on November 11, 2015, with a limitation for corrective lenses. During his medical examination in November 2015, the pilot reported that his total flight time was 4,250 hours. The pilot's logbook was not recovered during the investigation.

FAA airman records indicated that the pilot was involved in a landing incident in Boise, Idaho, on May 28, 2000. The pilot was found to be operating the airplane under the influence of alcohol with a blood alcohol concentration (BAC) of 0.26 percent, which was above the BAC legal limit of 0.04 percent for operating aircraft. The pilot surrendered his pilot and medical certificates after the incident. He reapplied for a medical certificate on July 5, 2005, and was granted an eligibility letter on August 10, 2005.

AIRCRAFT INFORMATION

The airplane was a pressurized, single-engine Cessna P210N that was manufactured in 1979. The airplane was configured to seat 4 individuals and had a maximum takeoff weight of 4,000 lbs. The airplane was equipped with a 310-horsepower Continental TSIO-520-P engine and a 3-blade McCauley propeller. No acrobatic maneuvers, including spins, were approved. The last annual maintenance inspection was conducted on June 1, 2015. The total airframe time at the time of the inspection was 3,329 hours, and the total engine time was 1,035 hours. According to available documentation, the airplane was flown about 28 hours since the last annual inspection.

METEOROLOGICAL INFORMATION

At 0853, the surface weather observation at Lamar, Colorado, located about 30 nautical miles southwest of the accident site, included wind from 160° at 9 knots, variable between 140° and 200°, surface visibility 10 miles, clouds broken 6,500 ft above ground level, temperature 13°C, dew point 6°C, and an altimeter setting of 30.25 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

The airplane impacted an open, harvested agricultural field in a wings-level, flat pitch attitude. The left wing was canted aft and the right wing was canted forward, consistent with the airplane being in a left spin at impact. The tail was bent slightly to the left of the fuselage and the engine was displaced slightly to the right. The fuselage was leaning slightly to the left. The landing gear was found in the retracted position.

The left wing remained attached to the fuselage. It was bent downward at the root and bent upward at the flap/aileron junction where the wing was resting on the ground. There was no leading edge compression damage observed to the left wing. The left flap was in the retracted position. The left main fuel tank was ruptured. There was no fuel in the left wing auxiliary fuel tank.

The right wing remained attached to the fuselage. It was bent downward at the root and bent upward in the middle of the right aileron where the wing was resting on the ground. No leading edge compression damage was observed to the right wing. The right flap was hanging down approximately 10°. Examination of the flap cables indicated the right flap cable was separated near the right wing root. The bottom side of the right wing had oil spray from the wing root extending toward the outboard end of the right flap. The right main fuel tank contained an undetermined amount of fuel. There was no fuel in the right wing auxiliary fuel tank.

The tail was fractured almost completely around its circumference at the dorsal. The rudder and elevators remained attached to the empennage. The rudder balance weight was separated from the top of the rudder and was found on the ground directly below the rudder.

The fuel selector handle was found positioned to the right tank, and the fuel selector valve was found in an intermediate position between RIGHT and OFF. The main fuel gauges indicated that the right tank was greater than 1/2 full and the left tank was full. The fuel strainer assembly was removed and contained about 4 ounces of fuel consistent with 100LL fuel; a sample tested negative for water contamination. The fuel strainer screen was installed properly with a cork gasket.

The airplane's pressurization system controls were on and the cabin pressure was set to 5,000 ft. The pressurization outflow and safety valve were examined. The outflow valve diaphragm was pliable and moved freely. The outflow valve was removed, and the diaphragm was compressed by hand. The pneumatic pressure port was covered to restrict airflow and the diaphragm did not move, which indicated normal operation. The safety valve was also removed for examination. The electric solenoid on the safety valve was found separated from the valve housing by impact damage. A fragment of the safety valve remained connected to the solenoid threads. The safety valve diaphragm was compressed, and a tear was observed where the solenoid had been installed. The "Overhead Vent Fan" switch was found in the LOW position.

The airplane was equipped with an aftermarket supplemental type certificate inflatable door seal. The cabin "Door Seal Activate" switch was observed to be in the OFF position.

Flight control cable continuity was confirmed from the flight controls to their respective attachment points of the elevator, rudder and ailerons. The flap actuator was found in the 0° position; however, the flap handle and flap indicator were in the 10° position. The elevator trim actuator was found in about a 5° tab up position.

The engine remained partially attached to the airframe by cables and lines; all four engine mount legs were broken. The exhaust and induction systems exhibited impact damage, and the oil sump was crushed upward into the crankcase. The throttle, mixture and propeller control arms moved freely between the mechanical stops. There was no oil spray observed on the top of the engine crankcase or cylinders, and there was no oil spray observed on the underside of the engine cowling.

The top spark plugs were removed, and they exhibited normal wear signatures when compared to the Champion Check-A-Plug chart. The cylinder combustion chambers were examined with a lighted borescope and no anomalies were noted. Drive train continuity and cylinder compression was confirmed on all six cylinders as the crankshaft was rotated by hand. Spark was also observed on all top ignition leads.

The engine accessories were removed from the engine and examined. The oil scavenge pump and engine oil pump were disassembled with no anomalies noted to the gears or cavities. The oil pressure relief valve exhibited signatures of normal operation. The engine-driven fuel pump was removed, and its drive coupling remained intact. The fuel pump turned freely by hand. The engine-driven fuel pump was disassembled with no anomalies noted. The fuel manifold valve was disassembled, and its diaphragm remained intact. The plunger and retaining nut remained secured, and the fuel screen was free of debris. The fuel nozzles were removed and found to be free of contamination. Fuel consistent with 100LL was found in various fuel system components and lines. The fuel was tested for the presence of water using water finding paste; no water contamination was identified. The two vacuum pumps were removed and disassembled with no discrepancies noted. The alternator drive turned freely by hand. The turbocharger remained attached to the exhaust system. The turbocharger compressor rotated freely and was coupled to the turbine wheel. The turbocharger's wastegate and controller exhibited no damage.

The 3-blade propeller remained attached to the crankshaft propeller flange. Examination of the propeller revealed all 3 blades were loose in the hub. The propeller blade marked No. 1 was bent forward about 90° about 6 inches from the hub. The outboard 10 inches of the blade exhibited a slight blade twist. The No. 2 blade exhibited a curved bend in the entire length of the blade. The No. 3 blade was bent slightly forward about 12 inches from the hub and exhibited a curved bend along the remaining length of the blade. All three blades exhibited burnishing of the leading edge; however, none of the blades exhibited nicks, gouges, or chordwise scratching of the blades.

During the onsite examination, a half-full bottle of vodka and numerous prescription and over-the-counter medications were found in the airplane.

MEDICAL AND PATHOLOGICAL INFORMATION

The El Paso County Coroner, Colorado Springs, Colorado conducted an autopsy of the pilot. The cause of death was the result of multiple blunt force injuries. Toxicology testing detected ethanol at 0.335 gm/dl in vitreous and 0.291 gm/dl in femoral blood as well as diphenhydramine at less than 0.050 ug/ml and zolpidem at 0.077 ug/ml in femoral blood.

The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing and identified ethanol at 0.0332 gm/dl in vitreous and 0.247 gm/dl in cavity blood. In addition, diphenhydramine was detected at levels too low to quantify, zolpidem was found at 0.049 ug/ml, and lorazepam was confirmed at 0.029 ug/ml in cavity blood. Clonidine was detected in liver but not in cavity blood. Ethanol is the type of alcohol present in beer, wine, and liquor. It is a social drug that acts as a central nervous system depressant. After ingestion, at low doses, it impairs judgment, psychomotor functioning, and vigilance; at higher doses, ethanol can cause coma and death. Generally, the rapid distribution of ethanol throughout the body after ingestion leads to similar levels in different tissues. 14 CFR 91 section 17 (a) prohibits any person from acting or attempting to act as a crewmember of a civil aircraft while having 0.040 gm/dl or more alcohol in the blood. The effects of alcohol on aviators are generally well understood; alcohol significantly impairs pilot performance, even at very low levels.

Diphenhydramine is a sedating antihistamine used to treat allergy symptoms and as a sleep aid. It is available over the counter under the names Benadryl and Unisom. Diphenhydramine carries the following FDA warning: may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery). Compared to other antihistamines, diphenhydramine causes marked sedation; it is also classed as a central nervous system (CNS) depressant and this is the rationale for its use as a sleep aid. Altered mood and impaired cognitive and psychomotor performance may also be observed. In a driving simulator study, a single dose of diphenhydramine impaired driving ability more than a blood alcohol concentration of 0.10 gm/dl. The range of blood levels in which diphenhydramine is thought to have psychoactive effects is between 0.025 and 0.112 ug/ml.

Zolpidem is a prescription CNS depressant used as a short-acting sleep aid, often sold with the name Ambien. It carries the warning, "Due to the rapid onset of action, zolpidem tartrate should only be taken immediately prior to going to bed. Patients should be cautioned against engaging in hazardous occupations requiring complete mental alertness or motor coordination such as operating machinery or driving a motor vehicle after ingesting the drug, including potential impairment of the performance of such activities that may occur the day following ingestion of zolpidem tartrate. Zolpidem tartrate showed additive effects when combined with alcohol and should not be taken with alcohol. Patients should also be cautioned about possible combined effects with other CNS-depressant drugs." Blood levels where the sedating effects are expected are between 0.025 and 0.30 ug/ml.

Lorazepam is a sedating benzodiazepine that is a Schedule IV controlled substance available by prescription and commonly used to treat anxiety; it is often sold with the name Ativan. It carries this warning, "As with all patients on CNS-depressant drugs, patients receiving lorazepam should be warned not to operate dangerous machinery or motor vehicles and that their tolerance for alcohol and other CNS depressants will be diminished." Blood levels where the sedating effects are expected in living subjects are between 0.16 ug/ml and 0.27 ug/ml.

Clonidine is a prescription blood pressure medication that is not generally considered impairing.

TESTS AND RESEARCH

The propeller manufacturer examined 25 digital photographs of the propeller that were provided by the National Transportation Safety Board's investigator-in-charge. According to the propeller manufacturer, the propeller sustained damage that appeared to be a result of impact and subsequent recovery of the airplane. There were no indications of propeller failure or malfunction before impact. Also, the propeller exhibited damage consistent with low rotational energy absorption during the impact sequence, which generally indicates low to no engine power at impact.

The NTSB Vehicle Recorder Division reviewed an excerpt of an ATC recording. The purpose of the study was to determine what was said in the pilot transmission. The sound wave form and spectral image were examined, and pitch contours identified. Sound was listened to by two different people, one who had no knowledge of the investigative facts. The text identified by the two listeners was "guys want me-to do-a muller." Additionally, the pilot's speech was noted to be markedly slurred.

ADDITIONAL INFORMATION

An aerobatic flight maneuver referred to as the "Muller" Tower, Zwiebelturm, or Spiral Tower, is attributed to Swiss and European aerobatic champion Eric Muller, who is believed to have invented it in 1974. It is an aerobatic maneuver where a pilot begins with a vertical climb, performs an aileron snap roll to the right, does a negative push to level out into horizontal flight at the top of the apogee, and enters a flat spin to the left at full throttle before pitching forward and exiting the maneuver in a dive.

Pilot Information

Certificate: Private
Age: 64, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used: 3-point
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: Yes
Medical Certification: Class 3 With Waivers/Limitations
Last FAA Medical Exam: 11/02/2015
Occupational Pilot: No
Last Flight Review or Equivalent: 11/02/2015
Flight Time: 4205 hours (Total, all aircraft) 

Aircraft and Owner/Operator Information

Aircraft Manufacturer: CESSNA
Registration: N6609P
Model/Series: P210N
Aircraft Category: Airplane
Year of Manufacture: 1978
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: P21000192
Landing Gear Type: Retractable - Tricycle
Seats: 4
Date/Type of Last Inspection: 06/01/2015, Annual
Certified Max Gross Wt.: 4001 lbs
Time Since Last Inspection: 28 Hours
Engines: 1 Reciprocating
Airframe Total Time: 3345 Hours at time of accident
Engine Manufacturer: Continental Motors
ELT: Installed, activated, did not aid in locating accident
Engine Model/Series: TSIO-520-P
Registered Owner: On file
Rated Power: 310 hp
Operator: On file
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: LAA, 3705 ft msl
Observation Time: 0853 MDT
Distance from Accident Site: 30 Nautical Miles
Direction from Accident Site: 215°
Lowest Cloud Condition:
Temperature/Dew Point: 13°C / 6°C
Lowest Ceiling: Broken / 6500 ft agl
Visibility: 10 Miles
Wind Speed/Gusts, Direction: 9 knots, 160°
Visibility (RVR):
Altimeter Setting: 30.25 inches Hg
Visibility (RVV):
Precipitation and Obscuration: No Precipitation
Departure Point: Rock Springs, WY (RKS)
Type of Flight Plan Filed: VFR
Destination: Oklahoma City, OK (PWA)
Type of Clearance: VFR Flight Following; VFR on top
Departure Time: 0645 MDT
Type of Airspace: 

Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Fatal
Latitude, Longitude:  38.495000, -102.290000

NTSB Identification: CEN16FA188 
14 CFR Part 91: General Aviation
Accident occurred Wednesday, May 18, 2016 in Sheridan Lake, CO
Aircraft: CESSNA P210N, registration: N6609P
Injuries: 1 Fatal.

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 May 18, 2016, about 0901 mountain daylight time, a Cessna P210N, N6609P, sustained substantial damage when it impacted a field in a flat spin about 4 miles northeast of Sheridan Lake, Colorado. The pilot, the sole occupant, received fatal injuries. The airplane was registered to and operated by the Stubblefield Construction Company under the provisions of the 14 Code of Federal Regulations as a Part 91 personal flight. Visual meteorological conditions prevailed at the time of the accident, and the airplane was receiving visual flight rules (VFR) flight following from the Federal Aviation Administration's (FAA) Air Route Traffic Control Center (ARTCC) in Denver, Colorado. The airplane departed the Rock Springs-Sweetwater County Airport (RKS), Rock Springs, Wyoming, about 0645 and was en route to the Wiley Post Airport (PWA), Oklahoma City, Oklahoma.

Earlier that morning, the pilot departed the Nampa Municipal Airport (MAN), Nampa, Idaho, about 0222 and landed in RKS about 0442. A witness at RKS reported that the pilot had the airplane topped off with 68 gallons of fuel. He reported that the pilot slept in the pilot's lounge for about one hour before departing to WPA.

Radar track data indicated that the airplane was flying on a southeast heading at 17,300 ft pressure altitude until 0847. Then the airplane started a series of turns, climbs, and descents that proceeded in a northerly direction. The air traffic controller stated on the radio that he suspected that the pilot might be hypoxic, and instructed the pilot to descend to a VFR altitude below 12,500 ft. The airplane started to descend and its last recorded radar return at 0900:32 indicated that the airplane's pressure altitude was 9,200 ft.

The airplane impacted a harvested field of milo in a wings-level, flat attitude. The left wing was canted aft and the right wing was canted forward indicative of a left hand spin. The tail was slightly to the left of the fuselage and the engine was slightly to the right. The fuselage was leaning slightly to the left. The landing gear was found in the retracted position.

The left wing remained attached to the fuselage. It was bent forward at the root and was bent upward at the flap/aileron junction where the wing was resting on the ground. There was no leading edge compression damage. The left flap was in the retracted position.

The right wing remained attached to the fuselage. It was bent downward at the root and was bent upward in the middle of the right aileron area where the wing was resting on the ground. There was no leading edge compression damage to the right wing. The right flap was hanging down approximately 10 degrees. Examination of the flap cables indicated the right flap cable was separated near the right wing root. The bottom side of the right wing had oil residue from the wing root extending outward toward the outboard end of the right flap.

The tail was fractured almost completely around its circumference at the dorsal. The rudder and elevators remained attached to the empennage. The rudder balance weight was separated from the top of the rudder and it was lying on the ground directly below the rudder.

Cessna 340A, N6239X, registered to Ninerxray Inc and operated by the pilot: Fatal accident occurred March 18, 2016 at Peter O. Knight Airport (KTPF), Davis Islands, Tampa, Hillsborough County, Florida


Louis Caporicci

Kevin Correna


The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Tampa, Florida
Textron Aviation; Wichita, Kansas
Continental Motors; Mobile, Alabama

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

Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

Ninerxray Inc: http://registry.faa.gov/N6239X



Location: Tampa, FL
Accident Number: ERA16FA133
Date & Time: 03/18/2016, 1130 EDT
Registration: N6239X
Aircraft: CESSNA 340
Aircraft Damage: Destroyed
Defining Event: Abrupt maneuver
Injuries: 2 Fatal
Flight Conducted Under: Part 91: General Aviation - Personal 

Analysis 

The airline transport pilot and pilot-rated passenger were departing on an instrument flight rules (IFR) cross country flight from runway 4 in a Cessna 340A about the same time that a private pilot and pilot-rated passenger were departing on a visual flight rules repositioning flight from runway 36 in a Cessna 172M. Visual meteorological conditions prevailed at the airport. The runways at the nontowered airport converged and intersected near their departure ends.

According to a witness, both airplanes had announced their takeoff intentions on the airport's common traffic advisory frequency (CTAF), which was not recorded; the Cessna 340A pilot's transmission occurred about 10 to 15 seconds before the Cessna 172M pilot's transmission. However, the witness stated that the Cessna 172M pilot's transmission was not clear, but he was distracted at the time. Both occupants of the Cessna 172M later reported that they were constantly monitoring the CTAF but did not hear the transmission from the Cessna 340A pilot nor did they see any inbound or outbound aircraft.

Airport video that captured the takeoffs revealed that the Cessna 172M had just lifted off and was over runway 36 approaching the intersection with runway 4, when the Cessna 340A was just above runway 4 in a wings level attitude with the landing gear extended and approaching the intersection with runway 36. Almost immediately, the Cessna 340A then began a climbing left turn with an increasing bank angle while the Cessna 172M continued straight ahead. The Cessna 340A then rolled inverted and impacted the ground in a nose-low and left-wing-low attitude. The Cessna 172M, which was not damaged, continued to its destination and landed uneventfully.

The Cessna 340A was likely being flown at the published takeoff and climb speed of 93 knots indicated airspeed (KIAS). The published stall speed for the airplane in a 40° bank was 93 KIAS, and, when the airplane reached that bank angle, it likely exceeded the critical angle of attack and entered an aerodynamic stall.

Examination of the Cessna 340A wreckage did not reveal any preimpact mechanical malfunctions that would have precluded normal operation. Because of a postcrash fire, no determination could be made as to how the radios and audio panel were configured for transmitting and receiving or what frequencies were selected. There were no reported discrepancies with the radios of the Cessna 172M, and there were no reported difficulties with the communication between the Cessna 340A and the Federal Aviation Administration facility that issued the airplane's IFR clearance. Additionally, there were no known issues related to the CTAF at the airport.

Toxicological testing detected unquantified amounts of atorvastatin, diphenhydramine, and naproxen in the Cessna 340A pilot's liver. The Cessna 340A pilot's use of atorvastatin or naproxen would not have impaired his ability to hear the radio announcements, see the other airplane taking off on the converging runway, or affected his performance once the threat had been detected. Without an available blood level of diphenhydramine, it could not be determined whether the drug was impairing or contributed to the circumstances of the accident. 

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The intentional low altitude maneuvering during takeoff in response to a near-miss with an airplane departing from a converging runway, which resulted in an exceedance of the airplane's critical angle of attack and a subsequent aerodynamic stall.

Findings

Aircraft
Performance/control parameters - Capability exceeded (Cause)
Airspeed - Not attained/maintained (Cause)
Angle of attack - Not attained/maintained (Cause)

Personnel issues
Decision making/judgment - Pilot (Cause)
Aircraft control - Pilot (Cause)
Communication (personnel) - Pilot
Communication (personnel) - Pilot of other aircraft

Factual Information

History of Flight

Takeoff
Airport occurrence

Initial climb
Abrupt maneuver (Defining event)
Aerodynamic stall/spin

Uncontrolled descent
Collision with terr/obj (non-CFIT)

Post-impact
Fire/smoke (post-impact)

On March 18, 2016, at 1130 eastern daylight time, a Cessna 340A, N6239X, was destroyed during takeoff when it impacted terrain following a near-miss with a Cessna 172M, N61801, at Peter O. Knight Airport (TPF), Tampa, Florida. The airline transport pilot and the pilot-rated passenger of the Cessna 340A were fatally injured. The private pilot and the pilot-rated passenger of the Cessna 172M were not injured, and the Cessna 172M was not damaged. The Cessna 340A was registered to Ninerxray, Inc., and operated by the pilot. The Cessna 172M was registered to and operated by Tampa Aviation Club, Inc. Visual meteorological conditions prevailed. An instrument flight rules (IFR) flight plan had been filed and activated for the Title 14 Code of Federal Regulations (CFR) Part 91 personal flight of the Cessna 340A that was destined for Pensacola International Airport, Pensacola, Florida. No flight plan was filed for the 14 CFR Part 91 personal flight of the Cessna 172M that was destined for Tampa Executive Airport, Tampa, Florida.

At the time of the accident, a temporary flight restriction (TFR) Notice to Airmen was in effect at TPF due to an airshow at MacDill Air Force Base, which was located about 5 nautical miles southwest of TPF. The TFR specified that only departures from runways 4 and 36 were authorized.

Earlier that day, the pilot of the Cessna 172M had successfully completed the oral examination and flight test for his private pilot certificate at TPF. The Cessna 172M was departing for its home airport following the flight test. The pilot-rated passenger in the Cessna 172M was the president of the corporation that owned and operated the Cessna 172M.

The president of the corporation that owned the Cessna 340A, reported that, on the day of the accident, one of the principals of the corporation was scheduled to be flown by the accident pilot to Fort Lauderdale, Florida; however, the trip was cancelled. The president further reported that, "without consulting any of the Principals of Ninerxray, Inc., and without their knowledge or consent," the pilot initiated the accident flight.

TPF does not have an air traffic control tower (ATCT). According to a chronological summary of communications with the ATCT at Tampa International Airport (located about 6 nautical miles northwest of TPF), at 1126, an occupant of the Cessna 340A contacted the Tampa ATCT using the remote communications outlet (RCO) at TPF for an IFR departure from runway 4 and was given an IFR clearance, but was held for departure. About 2 minutes later, he was advised to contact Tampa approach control on 119.9 MHz and was released for departure. There was no further contact between the Cessna 340A and Tampa ATCT.

The pilot of the Cessna 172M stated that he and the pilot-rated passenger monitored TPF's common traffic advisory frequency (CTAF) of 122.725 MHz from their taxi start point in front of the fixed base operator (FBO) to runway 36. The pilot-rated passenger stated that the radio transmissions were made by the pilot using the No. 3 radio, which was a Garmin GPS/Com transceiver. The pilot indicated that he initially transmitted on the CTAF that he was taking off from runway 1 but then corrected that he was taking off from runway 36. In separate written statements, both occupants of the Cessna 172M stated that they did not hear any other airplane on the CTAF frequency, and they saw no incoming or departing traffic.

A pilot-rated employee of the FBO at TPF reported that he heard a radio call on the CTAF from an occupant of the Cessna 340A stating that they were taking off from runway 4. About 10 to 15 seconds later, while he was talking to another person, he heard another transmission on the CTAF that "wasn't clear and direct" but indicated that an airplane was departing from runway 1, then corrected to runway 36. The employee asked the person he was talking with if the second radio call was at TPF, to which the individual replied that he did not hear it and did not think so.

The pilot of the Cessna 172M stated that he performed a short field takeoff, and just after liftoff, he heard but did not see what he thought was a twin-engine airplane with full throttle "descending off the right [side] of the airplane." He then heard a crash and saw a fireball at the departure end of runway 36. The pilot-rated passenger stated that, as the Cessna 172M climbed through about 200 ft near the north end of the runway, he heard another airplane. He looked out the right window and saw the Cessna 340A almost directly below "stall and crash." Because the pilot felt it unsafe to return to TPF, he elected to continue to his planned destination.

The airport was equipped with a security camera that pointed to the intersection of runways 4/22 and 18/36. The security camera depicted the latter portion of the departures of both airplanes. Review of the recorded video revealed that it depicted the Cessna 172M becoming airborne before the runway intersection and continuing in a slow climb straight ahead over the runway until just before the intersection with runway 4. As the Cessna 172M approached the intersection, the Cessna 340A entered the left side of the video just above runway 4 in a wings level attitude with the landing gear extended. The Cessna 340A was observed in a climbing left turn while the Cessna 172M continued straight ahead. The Cessna 340A then continued in a climbing left turn, rolled inverted, and, while in a nose- and left-wing-low attitude, impacted the ground north of the intersection. A fireball occurred almost immediately after impact, and the Cessna 172M continued in a northerly direction out of view of the camera.

A camera at a berth on the opposite (eastern) side of the shipping channel adjacent to the airport also recorded the accident sequence. The left side of the video included part of the airport where runways 4 and 36 intersected. In the recording, the Cessna 172M was first seen coming into view airborne over runway 36 and climbing straight out over the runway. As it neared the intersection of runway 4/22, the Cessna 340A came into view, just lifting off from runway 4 and almost immediately entering a hard-left turn. The Cessna 340A continued the turn, passing behind the Cessna 172M while climbing and closing on the Cessna 172M's right side. The Cessna 340A almost reached the Cessna 172M's altitude, but continued the left turn to an inverted attitude, and descended into the ground. A fireball then erupted.

A witness who was on a boat in the shipping channel next to runway 36 stated that he heard a "screaming engine noise," which caused him to look toward the two airplanes. He saw that a "twin engine plane was behind and below the single engine plane." The twin engine airplane was in a left turn; it then caught a wing and slammed into the ground with an "instantaneous" explosion. He also indicated that the airplanes were so close that he thought they would collide (The figure below shows the airport diagram and accident site location).

Pilot Information

Certificate: Airline Transport; Flight Instructor; Commercial
Age: 54, Male
Airplane Rating(s): Multi-engine Land; Single-engine Land; Single-engine Sea
Seat Occupied: Left
Other Aircraft Rating(s): Helicopter
Restraint Used: Unknown
Instrument Rating(s): Airplane; Helicopter
Second Pilot Present: Yes
Instructor Rating(s): Airplane Multi-engine; Airplane Single-engine; Helicopter; Instrument Airplane; Instrument Helicopter
Toxicology Performed: Yes
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 06/05/2014
Occupational Pilot: No
Last Flight Review or Equivalent: 03/12/2015
Flight Time: 5195 hours (Total, all aircraft), 25 hours (Last 90 days, all aircraft) 

Pilot-Rated Passenger Information

Certificate: Private
Age: 55, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Right
Other Aircraft Rating(s): None
Restraint Used: Unknown
Instrument Rating(s): None
Second Pilot Present: Yes
Instructor Rating(s): None
Toxicology Performed: Yes
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 06/06/2014
Occupational Pilot: No
Last Flight Review or Equivalent: 06/27/2014
Flight Time: 375 hours (Total, all aircraft) 

According to Federal Aviation Administration (FAA) records, the pilot, who was seated in the left seat of the Cessna 340A, age 54, held an airline transport pilot certificate with an airplane multi-engine land rating. He also held commercial, flight instructor, and ground instructor certificates. At the commercial level, he held ratings for airplane single-engine land and sea, rotorcraft helicopter, and instrument helicopter, and, at the flight instructor level, he held ratings for airplane single- and multi-engine, rotorcraft helicopter, and instrument airplane and helicopter. His most recent FAA second-class medical certificate with no limitations was issued on June 5, 2014. As of October 2, 2015, the pilot reported a total time of 5,195 hours of which 284 hours were in multi-engine airplanes. His last flight review in accordance with Title 14 CFR Part 61 section 56 was on March 12, 2015.

According to FAA records, the right seat occupant of the Cessna 340A, age 55, held a private pilot certificate with an airplane single-engine land rating. His most recent FAA second-class medical certificate with no limitations was issued on June 6, 2014. On the application for his last medical certificate, he listed a total flight time of 375 hours.

According to FAA records, the pilot, who was seated in the left seat of the Cessna 172M, age 30, held a private pilot certificate with airplane single-engine land rating issued earlier that day. His most recent FAA third-class medical certificate with no limitations was issued on December 7, 2015. On the FAA 8710-1 application form for his private pilot certificate, he listed a total flight time of 40 hours of which 21.4 hours were as instruction received and 18.6 hours were solo.

According to FAA records, the right seat occupant of the Cessna 172M, age 69, held airline transport, commercial, and flight instructor pilot certificates. At the airline transport pilot level, he held an airplane multi-engine land rating, and, at the commercial level, he held ratings for airplane single-engine land and sea. At the flight instructor level, he held ratings for airplane single- and multi-engine and instrument airplane. He reported a total flight time of 6,530 hours and about 3,000 hours in a Cessna 172. 

Aircraft and Owner/Operator Information

Aircraft Manufacturer: CESSNA
Registration: N6239X
Model/Series: 340 A
Aircraft Category: Airplane
Year of Manufacture: 1977
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 340A0436
Landing Gear Type: Retractable - Tricycle
Seats: 6
Date/Type of Last Inspection: 02/15/2016, Annual
Certified Max Gross Wt.: 6390 lbs
Time Since Last Inspection:
Engines: 2 Reciprocating
Airframe Total Time:  3963.1 Hours as of last inspection
Engine Manufacturer: CONT MOTOR
ELT: C126 installed, not activated
Engine Model/Series: TSIO-520-EBcN
Registered Owner: NINERXRAY INC
Rated Power: 335 hp
Operator: On file
Operating Certificate(s) Held: None



Cessna 340A

The six-place, low-wing, retractable-gear Cessna 340A airplane, serial number 340A0436, was manufactured in 1977. It was powered by two 335-horsepower Continental Motors, Inc., TSIO-520-NB engines and equipped with Hartzell PHC-C3YF-2UF/FC7693DFB constant-speed propellers. The airplane was also equipped with RAM Option 3 vortex generators on both wings and tail that were installed in 1996 in accordance with Supplemental Type Certificate (STC) SA7975SW. The airplane's maximum allowable gross weight was 6,390 pounds.

The airplane was equipped with a Garmin GNS-530W installed in the "pilots view position" that was the No. 1 communication and navigation transceiver. It was connected to the No. 1 position of the audio panel. A Garmin GNS 430 with navigation and communication capability was installed in the center instrument panel.

The maintenance records were reportedly in the airplane at the time of the accident. Review of copies of the Cessna 340A's maintenance record entries indicated that the airplane's last annual inspection was signed off as being completed on February 15, 2016. At that time, the airplane's total time was 3,963.10 hours.

The Cessna 340A's weight at the time of the accident was calculated using the empty weight when the airplane was modified in 1996 (about 4,478 pounds), the weights of the occupants from their most recent FAA medical examinations (208 and 207 pounds), and the weight of full usable fuel in each main fuel tank, each auxiliary fuel tank, and the locker fuel tank (1,098 pounds). The calculations indicated that the takeoff weight was about 5,991 pounds.

The Flight Manual Supplement associated with the 1996 modifications specified that the takeoff and climb speed to 50 ft was 93 knots indicated airspeed (KIAS) for weights between 5,990 and 6,390 pounds.

A review of the stall speed chart in the Flight Manual Supplement revealed that at 6,390 pounds, with flaps retracted and landing gear up, the stall speeds at 0°, 40°, and 60° of bank were 81, 93, and 115 KIAS, respectively. There were no published stall speeds for flaps retracted and landing gear down.



Cessna 172M

The four-place, high-wing, fixed-gear Cessna 172M airplane, serial number 17264811, was manufactured in 1975. It was equipped with three communication and navigation transceivers, which included a Garmin GNC-300XL GPS/Com system that was installed and interfaced to the existing audio system after the airplane was manufactured. According to the pilot-rated passenger, in November 2015, there had been static over the intercom, and the audio panel had been replaced. The pilot-rated passenger reported that all three radios were checked after the accident with no discrepancies reported.

Review of the Cessna 172M's maintenance records indicated that an annual inspection was completed on July 8, 2015, at an airplane total time of 9,412.4 hours. The next annual inspection was completed on August 10, 2016, at an airplane total time of 9,601.1 hours. There was no entry between the 2015 and 2016 annual inspection entries related to the airplane's radios. 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: TPF, 7 ft msl
Observation Time: 1135 EDT
Distance from Accident Site: 0 Nautical Miles
Direction from Accident Site:
Lowest Cloud Condition: Clear
Temperature/Dew Point: 26°C / 20°C
Lowest Ceiling: None
Visibility:  10 Miles
Wind Speed/Gusts, Direction: 9 knots, 210°
Visibility (RVR):
Altimeter Setting: 30.001 inches Hg
Visibility (RVV):
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Tampa, FL (TPF)
Type of Flight Plan Filed: IFR
Destination: PENSACOLA, FL (PNS)
Type of Clearance: IFR
Departure Time: 1130 EDT
Type of Airspace: 

The 1115 automated surface observation taken at TPF reported wind from 210° at 9 knots, 10 statute miles visibility, and clear skies. The temperature and dew point were 27°C and 20°C, respectively, and the altimeter setting was 30.00 inches of mercury. 

Airport Information

Airport: PETER O KNIGHT (TPF)
Runway Surface Type: Asphalt
Airport Elevation: 7 ft
Runway Surface Condition: Dry
Runway Used: 04
IFR Approach: None
Runway Length/Width: 3580 ft / 100 ft
VFR Approach/Landing: None 

TPF had two runways, runway 4/22, which was 3,580 ft long and 100 ft wide, and runway 18/36, which was 2,687 ft long and 75 ft wide. The runways intersected near their northern ends. A shipping channel was located just east of and parallel to runway 18/36. 



Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Destroyed
Passenger Injuries: 1 Fatal
Aircraft Fire: On-Ground
Ground Injuries: N/A
Aircraft Explosion: On-Ground
Total Injuries: 2 Fatal
Latitude, Longitude:  27.919722, -82.447778

Examination of the accident site revealed that the Cessna 340A impacted flat terrain about 40 ft to the right of and 250 ft from the departure end of runway 36. The initial ground scars indicated a magnetic heading of about 10°. The wreckage came to rest upright, and both engines were separated from the wings. The right engine was located between the beginning of the wreckage path and the main wreckage, and the left engine was laying on the right wing.

A postcrash fire consumed the majority of fuselage from the nose of the airplane to the beginning of the empennage. Both wings were substantially consumed by fire. Remnants of all flight control surfaces were found at the scene. Flight control continuity could only be confirmed between the wings and the center cabin and between the tail and the center cabin due to the extensive fire damage. The hardware attaching the elevator trim pushrod assembly to the elevator trim actuator remained intact, and the elevator trim tab actuator was extended 1.4 inches, which equates to 5° tab trailing-edge-down. The rudder trim tab actuator was extended 1.0 inch, which equates to 5° tab trailing-edge-right. The aileron trim tab actuator was extended 1.7 inches, which equates to a neutral setting. Examination of the flap motor revealed the flap chain position correlated to flaps retracted.

The frequencies of the communication transceivers and the configuration of the audio control panel could not be determined due to the postcrash fire, which consumed the cockpit.

Engine crankshaft continuity and cylinder compression were confirmed on both engines. Significant thermal and impact damage were noted to both engines and their accessories. No preexisting anomalies were found that would have precluded normal operation.

Both propellers were separated from their respective engines, and both exhibited leading edge burnishing, bending, and twisting of the blades.

The Cessna 172M was examined the day of the accident by several FAA inspectors; no operational testing of the radios was performed. The pilot-rated passenger reported that subsequent testing of all three radios was satisfactory. 

Communications

TPF did not have a control tower, and the CTAF of 122.725 MHz was not recorded, nor was it required to be. Following the accident, equipment that recorded the CTAF was installed at TPF.

There were no reported communication difficulties with Tampa ATCT.

According to an individual who provided oversight for TPF, to their knowledge, there had been no formal or informal complaints about the CTAF pertaining to reception issues related to buildings and/or structures.



Medical And Pathological Information

The Hillsborough County Medical Examiner Department, Tampa, Florida, performed postmortem examinations of the Cessna 340A pilot and pilot-rated passenger, and also toxicological testing. The cause of death for both was listed as blunt impact to head and neck. Toxicology testing or liver specimens of the pilot and pilot-rated passenger revealed the results for both were negative for volatiles, drugs of abuse, comprehensive drug screen, and benzodiazepines.

The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma performed toxicological testing of specimens from the Cessna 340A pilot and pilot-rated passenger. The toxicology report for the pilot indicated no ethanol was detected in the submitted muscle and brain specimens. Unquantified amounts of atorvastatin, diphenhydramine, and naproxen were detected in the submitted liver specimen. Atorvastatin is a cholesterol lowering prescription medication commonly called Lipitor. Naproxen is an anti-inflammatory analgesic available over the counter and by prescription, often with the names Aleve and Naprosyn. Neither of these drugs are considered impairing. Diphenhydramine is a sedating antihistamine that has been shown to impair a driver's ability to safely operate a car. Testing for carbon monoxide and cyanide was not performed.

The toxicology report for the pilot-rated passenger indicated no ethanol was detected in the submitted muscle and brain specimens, and no tested drugs were detected in the submitted liver specimen. Testing for carbon monoxide and cyanide was not performed.

Drug and alcohol testing was not requested or performed for the occupants of the Cessna 172M.



NTSB Identification: ERA16FA133
14 CFR Part 91: General Aviation
Accident occurred Friday, March 18, 2016 in Tampa, FL
Aircraft: CESSNA 340A, registration: N6239X
Injuries: 2 Fatal.

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 March 18, 2016, at 1130 eastern daylight time, a Cessna 340A, N6239X, was destroyed when it impacted terrain during an initial climb following a takeoff at Peter O. Knight Airport (TPF), Tampa, Florida. The airline transport pilot and the private pilot were fatally injured. Visual meteorological conditions prevailed. An instrument flight rules flight plan had been filed. The personal flight, to Pensacola International Airport (PNS) Pensacola, Florida, was operating under the provisions of 14 Code of Federal Regulations Part 91.

TPF had two runways, runway 4/22, which was 3,580 feet long and 100 feet wide, and runway 18/36, which was 2,687 feet long and 75 feet wide. The runways intersected near their northern ends. There was shipping channel just east of, and parallel to runway 18/36.

Wind, recorded at the airport at 1135, was from 210 degrees true at 9 knots. However, a temporary flight restriction (TFR) was in effect at the time of the accident due to an airshow at nearby MacDill Air Force Base. The TFR extended in a 5-nautical-mile radius from the center of the base, from the surface to 15,000 feet unless authorized by air traffic control. The TFR extended over the southern ends of both runways at TPF. Multiple sources indicated that while the twin-engine Cessna 340 was taking off from runway 4, a single-engine Cessna 172M, N61801, was taking off from runway 36.

The airport did not have an operating control tower, and the common traffic advisory frequency (CTAF) was not recorded, nor was it required to be.

There were two pilots in the Cessna 172; the pilot in command (PIC) who had just passed his private pilot check ride at TPF, and a pilot-rated passenger, who had also been the PIC's flight instructor. The Cessna 172 was departing for its home airport following the check ride. In separate written statements, both pilots stated that the PIC made an advisory radio call indicating they would be taking off from runway 36. They also stated that they did not hear any other airplane on the frequency, with the PIC noting that they monitored frequency 122.725 [the CTAF frequency] from the taxi start point in front of the fixed base operator (FBO) to runway 36.

There was also a radio at the FBO, and a witness who was there at the time of the accident stated that he heard a radio call from the Cessna 340, and about 10-15 seconds later, heard what he thought could have been a call from the Cessna 172, but it wasn't as clear, partly because he was speaking to someone else at the time.

Airport and cross-channel security cameras captured the latter part of the accident flight. They partially showed the Cessna 340 taking off from runway 4 and the Cessna 172 taking off from runway 36.

The airport security camera was pointed such that the intersections of runways 4 and 36 were in the upper left quadrant of the video. The video initially showed the Cessna 172 on its takeoff roll. It lifted off the runway well before the runway intersection, continued a slow climb straight ahead, and gradually disappeared toward the upper left portion of the video.

When the video initially showed the Cessna 340, it was already about 20 feet above runway 4. It then made a hard left turn and appeared to pass behind the Cessna 172, still in a left turn, but climbing. It then appeared to briefly parallel the course of the Cessna 172, but the left-turn bank angle continued to increase, and the airplane's nose dropped. The airplane then descended, impacting the ground in an inverted, extremely nose-low attitude. During the impact sequence, the airplane burst into flames.

There was also a camera at a berth on the opposite (eastern) side of the shipping channel. The camera was pointing northward, up the shipping channel. However, the left side of the video also included part of the airport where runways 4 and 36 intersected.

In the recording, the Cessna 172 was first seen coming into view airborne off runway 36, and climbing straight out over the runway. As it neared the intersection, the Cessna 340 came into view, just lifting off from runway 4 and almost immediately beginning a hard left turn. The Cessna 340 continued the turn, passing behind the Cessna 172 while climbing and closing on the Cessna 172's right side. It almost reached Cessna 172's altitude, but continued the left turn onto its back, and descended into the ground. A fireball then erupted that initially extended well below and in front of the Cessna 172.

The Cessna 172 pilot-rated passenger, in the right seat, stated that as his airplane climbed through about 200 feet, he heard another airplane. He looked out the right window and saw the Cessna 340 almost directly below, "stall and crash." The PIC of the Cessna 172, in the left seat, stated that he heard but did not see what he thought was a twin engine airplane, then saw a fireball at the departure end of the runway he just departed.

The videos also recorded a boat heading north, mid-channel, in the waterway next to runway 36 when the accident occurred. A witness on the boat heard "screaming engine noise," which caused him to look toward the two airplanes. He saw that the "twin engine plane was behind and below the single engine plane." The twin engine airplane was in a left turn; it then caught a wing and slammed into the ground, with an "instantaneous" explosion.

The Cessna 340 impacted flat terrain about 40 feet to right of, and 250 feet from the departure end of runway 36, in the vicinity of 27 degrees, 55.16 minutes north latitude, 082 degrees, 26.87 degrees west longitude. The airplane was mostly destroyed in a post impact fire, and initial ground scars indicated an approximate heading of 010 degrees magnetic. Ground scars were consistent with the airplane having impacted at a high descent angle and inverted. However, the main wreckage came to rest right side up.

The fire consumed the majority of fuselage, from the nose of the airplane to the beginning of the empennage. Both wings were also substantially consumed by fire. The engines had separated from the wings, with the right engine found between the beginning of the wreckage path and the main wreckage, and the left engine found on top of the right wing.

Remnants of all flight control surfaces were found at the scene, but flight control continuity could only be confirmed between the wings and center cabin, and the tail and center cabin due to the extent of fire damage.

Both propellers were found broken off from their respective engines, and both sets of propellers exhibited blade leading edge burnishing, and bending and twisting. Engine crankshaft continuity was confirmed on both engines, as was compression. Significant thermal and impact damage was noted, but no preexisting anomalies were found that would have precluded normal operation.