Thursday, September 08, 2011

Cessna 208B Caravan, N207DR and Cessna 207, N73789: Accident occurred September 02, 2011 in Nightmute, Alaska

NTSB Identification: ANC11FA091A 
Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Friday, September 02, 2011 in Nightmute, AK
Aircraft: CESSNA 208B, registration: N207DR
Injuries: 1 Fatal,1 Uninjured.


NTSB Identification: ANC11FA091B

Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Friday, September 02, 2011 in Nightmute, AK
Aircraft: CESSNA T207A, registration: N73789
Injuries: 1 Fatal,1 Uninjured.

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.  


A Cessna 208B and a Cessna 207 collided in flight in daylight visual meteorological conditions. The Cessna 208B and the Cessna 207 were both traveling in an easterly direction. According to the Cessna 207 pilot, the airplanes departed from two neighboring remote Alaskan villages about the same time, and both airplanes were flying along similar flight routes. While en route, the Cessna 207 pilot talked with the Cessna 208B pilot on a prearranged, discreet radio frequency, and the two agreed to meet up in flight for the return to their home airport. The Cessna 207 pilot said that the pilot of the Cessna 208B flew his airplane along the left side of her airplane while she was in level cruise flight at 1,200 feet mean sea level and that they continued to talk via the radio. Then, unexpectedly and unannounced, the pilot of the Cessna 208B maneuvered his airplane above and over the top of her airplane. She said that she immediately told the Cessna 208B pilot that she could not see him and that she was concerned about where he was. She said that the Cessna 208B pilot then said, in part: "Whatever you do, don't pitch up." The next thing she recalled was seeing the wings and cockpit of the descending Cessna 208B pass by the right side of her airplane, which was instantly followed by an impact with her airplane's right wing. She said that after the collision, the Cessna 208B passed underneath her airplane from right-to-left before beginning a gradual descent that steepened as the airplane continued to the left. It then entered a steep, vertical, nose-down descent before colliding with the tundra-covered terrain below followed by a postcrash fire. Unable to maintain level cruise flight, the Cessna 207 pilot selected an area of rolling, tundra-covered terrain as a forced landing site. 

An examination of both airplanes revealed impact signatures consistent with the Cessna 208B's vertical stabilizer impacting the Cessna 207's right wing. A portion of crushed and distorted wreckage, identified as part of the Cessna 208B's vertical stabilizer assembly, was found embedded in the Cessna 207's right wing. The Cessna 208B's severed vertical stabilizer and rudder were found about 1,000 feet west of the Cessna 208B's crash site.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot's failure to maintain adequate clearance while performing an unexpected and unannounced abrupt maneuver, resulting in a midair collision between the two airplanes.

HISTORY OF FLIGHT

On September 2, 2011, about 1335 Alaska daylight time, a Cessna 208B airplane, N207DR, and a Cessna 207 airplane, N73789, collided in midair about 9 miles north of Nightmute, Alaska. Both airplanes were being operated as charter flights under the provisions of 14 Code of Federal Regulations (CFR) Part 135 in visual meteorological conditions when the accident occurred. The Cessna 208B was operated by Grant Aviation Inc., Anchorage, Alaska, and the Cessna 207 was operated by Ryan Air, Anchorage, Alaska. Visual flight rules (VFR) company flight following procedures were in effect for each flight. The sole occupant of the Cessna 208B, an airline transport pilot, sustained fatal injuries. The sole occupant of the Cessna 207, a commercial pilot, was uninjured.  The Cessna 208B was destroyed, and the Cessna 207 sustained substantial damage. After the collision, the Cessna 208B descended uncontrolled and impacted tundra-covered terrain, and a postcrash fire consumed most of the wreckage. The Cessna 207’s right wing was damaged during the collision and the subsequent forced landing on tundra-covered terrain. Both airplanes were based at the Bethel Airport, Bethel, Alaska, and were returning to Bethel at the time of the collision. The Cessna 208B departed from the Toksook Bay Airport, Toksook Bay, Alaska, about 1325, and the Cessna 207 departed from the Tununak Airport, Tununak, Alaska. 

During separate telephone conversations with the National Transportation Safety Board (NTSB) investigator-in-charge on September 2, the chief pilot for Ryan Air, as well as the director of operations for Grant Aviation, independently reported that both pilots had a close personal relationship.

During an initial interview with the NTSB IIC on September 3, in Bethel, the pilot of the Cessna 207 reported that both airplanes departed from the neighboring Alaskan villages about the same time and that both airplanes were en route to Bethel along similar flight routes. She said that, just after takeoff from Tununak, she talked with the pilot of the Cessna 208B on a prearranged, discreet radio frequency, and the two agreed to meet up in-flight for the flight back to Bethel. She said that, while her airplane was in level cruise flight at 1,200 feet above mean sea level (msl), the pilot of the Cessna 208B flew his airplane along the left side of her airplane, and they continued to talk via radio. She said that the pilot of the Cessna 208B then unexpectedly and unannounced climbed his airplane above and over the top of her airplane. She said that she immediately told the pilot of the Cessna 208B that she could not see him and that she was concerned about where he was. She said that the Cessna 208B pilot then said, in part: "Whatever you do, don't pitch up." The next thing she recalled was moments later seeing the wings and cockpit of the descending Cessna 208B pass by the right the side of her airplane, which was instantaneously followed by an impact with her airplane’s right wing.

The Cessna 207 pilot reported that, after the impact, while she struggled to maintain control of her airplane, she saw the Cessna 208B pass underneath her airplane from right-to-left, and it began a gradual descent, which steepened as the airplane continued to the left and away from her airplane. She said that she told the pilot of the Cessna 208B that she thought she was going to crash.She said that the pilot of the Cessna 208B simply stated, “Me too.” She said that she watched as the Cessna 208B continued to descend, and then it entered a steep, vertical, nose-down descent before it collided with the tundra-covered terrain below. She said that a postcrash fire started instantaneously upon impact.

Unable to maintain level cruise flight and with limited roll control, the Cessna 207 pilot selected an area of rolling, tundra-covered terrain as a forced landing site. During touchdown, the airplane’s nosewheel collapsed, and the airplane nosed down.  The Cessna 207’s forced landing site was about 2 miles east of the Cessna 208B’s accident site. 

PERSONNEL INFORMATION

Cessna 208B:

The pilot, age 24, held an airline transport pilot certificate with airplane single-engine land and multiengine land ratings. The pilot’s most recent second-class medical certificate was issued on December 23, 2010, and contained no limitations.

According to information provided by Grant Aviation, the pilot's total aeronautical experience was 3,710 flight hours with 875 flight hours in the accident airplane make and model. In the 90 and 30 days prior to the accident, the pilot accrued 320 flight hours and 92 flight hours, respectively.

On August 30, the pilot's duty day started at 0800 and ended at 1930, and he flew 4.0 hours. On August 31, his duty day started at 0800 and ended at 2000, and he flew 6.3 hours. On September 1, his duty day started at 0800 and ended at 1930, and he flew 4.5 hours. On the day of the accident, September 2, his duty day started about 0800, and he flew about 3.0 hours before the accident.

According to the operator, the pilot was hired by the company on August 22, 2008, after satisfactorily completing the new hire training curriculum, including Cessna 207 pilot-in-command (PIC) ground and flight training. On August 28, 2008, he was assigned to fly as PIC of Cessna 207 airplanes at the company base in Bethel.

On August 13, 2011, the pilot was upgraded to captain of Cessna 208 airplanes. His most recent ride 14 CFR 135.293 airman competency/proficiency check was on May 31, 2011. A company check airman administered the check ride.

Cessna 207:

The pilot, age 25, held a commercial pilot certificate with airplane single-engine land, multiengine land, and instrument airplane ratings. Her most recent first-class medical certificate was issued on April 28, 2011, and contained no limitations.

According to information provided by Ryan Air, the pilot's total aeronautical experience was 1,670 flight hours, with 216 flight hours in the accident airplane make and model. In the 90 and 30 days prior to the accident, the pilot accrued a total of 209 flight hours and 48 flight hours, respectively.

On August 30, the pilot's duty day started at 0800 and ended at 1700, and she flew 2.8 hours. On August 31, her duty day started at 0800 and ended at 1600, and she flew 2.3 hours. On September 1, her duty day started at 0800 and ended at 1700, and she flew 2.4 hours. On the day of the accident, September 2, her duty day started about 0800, and she flew about 3.0 hours before the accident.

According to the operator, the pilot was officially hired by the company on May 18, 2010, and, at that time, her total flight experience was 690 hours. She completed her initial company training, including Cessna 207 PIC ground and flight training, on May 18, 2010.

On June 5, 2010, she successfully completed her initial second-in-command (SIC) pilot training for CASA 212 airplanes, which included both ground and flight training, and she was assigned to fly SIC in CASA 212 airplanes at the company's base in Bethel.

On June 8, 2011, she completed her initial operating experience in Cessna 207 airplanes, and she was assigned to fly as PIC of Cessna 207 airplanes at the company base in Bethel.

Her most recent 14 CFR 135.293 airman competency/proficiency check ride was on June 2, 2011. A company check airman administered the check ride in a company Cessna 207 airplane in Bethel.

Company Information

  Grant Aviation

Grant Aviation holds a Part 135 operating certificate for commuter and on-demand operations. Company facilities are located at Anchorage, Bethel, Dillingham, Emmonak, Homer, and Kenai, Alaska.

A review of the company's operations manual revealed that the president, director of maintenance, director of operations, and chief pilot are designated as having the authority of exercising operational control over company aircraft and/or flight crews. The president, chief pilot, director of maintenance, and director of operations all reside in Anchorage.

In addition, the company operations manual states, in part: “The pilot-in-command always retains the final authority for safe operation of the aircraft and compliance with Federal Aviation Regulations.”

  Ryan Air

Ryan Air holds a Part 135 operating certificate for commuter and on-demand operations. Company facilities are located at Anchorage, Bethel, Aniak, St. Mary’s, Emmonak, Unalakleet, Nome, and Kotzebue, Alaska.

A review of the company's operations manual revealed that the president, director of maintenance, director of operations, and chief pilot, are designated as having the authority of exercising operational control over company aircraft and/or flight crews. The president, director of maintenance, and director of operations reside in Anchorage, and the chief pilot resides in Bethel.  

In addition, the company operations manual states, in part: “The Pilot-in-command always retains the final authority for safe operation of the aircraft and compliance with Federal Aviation Regulations.”

AIRPLANE INFORMATION

Cessna 208B:

The Cessna 208B airplane was an unpressurized, single-engine turboprop, equipped with a Pratt & Whitney PT6A-114A engine that produces 675 horsepower.  It was outfitted with a Hartzell three-bladed propeller with composite blades.

The airplane had a total time in service of 8,483 hours. The airplane was maintained on an Approved Airworthiness Inspection Program (AAIP). The most recent inspection event was on August 21, 2011, 46 hours before the accident.

The Cessna 208B’s paint scheme consisted of a base color of white with red accent striping which extended along both sides of the fuselage.  The wings, vertical stabilizer, rudder, horizontal stabilizer, and elevators were all painted white. 

Cessna 207:

The Cessna 207 airplane was unpressurized and was equipped with a single, reciprocating Continental Motors IO-520F engine that produces 300 horsepower.

The airplane had accumulated a total time in service of 19,562.9 hours. The airplane was maintained on an AAIP. The most recent inspection was accomplished on August 3, 2011, 47.2 hours before the accident.

The Cessna 207’s paint scheme consisted of red and black, with silver accent striping which extended along both sides of the fuselage.  The wings, vertical stabilizer, rudder, horizontal stabilizer, and elevators were all painted red. 

METEOROLOGICAL INFORMATION

The closest official weather observation station is at the Toksook Bay Airport, Toksook Bay.  On September 2, 2011, at 1356, an Aviation Routine Weather Report (METAR) was reporting in part: Wind, 130 degrees at 14 knots; visibility, 10 statute miles; clouds, 1,100 feet overcast; temperature, 46 degrees F; dew point, 42 degrees F; altimeter, 29.84 inHg.

Pilots who were flying in the area about the same time as the accident reported unlimited visibility with patchy clouds between 1,500 to 2,000 feet.

COMMUNICATIONS

According to the pilot of the Cessna 207, both pilots were communicating on a prearranged radio frequency of 126.30.

Both airplanes were operating in Class E airspace. The pilots were not in contact with any air traffic control facility, nor were they required to be.

Radar coverage was not available in the accident area at the flights’ altitudes.

WRECKAGE AND IMPACT INFORMATION

Cessna 208B:

The wreckage of the Cessna 208B had extensive ground impact and fire damage. Portions of the airplane wreckage were still burning when the NTSB IIC and the Alaska State Trooper arrived at the scene.  A majority of the main fuselage, cockpit/cabin area, and engine were found embedded in a large crater.

The entire cockpit/cabin area from the instrument panel to just forward of the horizontal stabilizer was consumed by fire.

The Pratt & Whitney PT6A-114A turbine engine was found imbedded, vertically, into the tundra-covered terrain, leaving only the aft portion of the engine accessory gearbox visible.

Portions of the incinerated fuselage structure and the wings of the airplane were in a vertical, nose-down attitude. The longitudinal axis of the fuselage was oriented on a magnetic heading of about 040 degrees. (All heading/bearings noted in this report are oriented toward magnetic north.)

The entire airplane was separated into several main groups. The wings were separated from the fuselage and displayed extensive spanwise, leading-edge-aft crushing and folding. The forward spar of each wing was compressed to its respective aft spar. The wings were oriented in a near-vertical attitude with the leading edge of the wings oriented down, about 2 feet beneath the surface of the soft and spongy terrain. Each aileron and flap assembly remained attached to the trailing edge of their respective wing. Both wing lift struts were still attached to the wings, but both were separated at the lower fuselage attach points as a result of fuselage incineration.

The empennage separated from the fuselage just forward of the vertical stabilizer attach point. The empennage was inverted and located just aft of the incinerated fuselage. The right horizontal stabilizer displayed leading-edge-aft crushing and upward buckling on the underside of the stabilizer. The left horizontal stabilizer displayed aft crushing about midspan and aft compression and folding of the leading edge along the outboard half of the stabilizer.

The vertical stabilizer and rudder assemblies were severed about 18 inches outboard of the fuselage attachment points. The upper portions of the vertical stabilizer and rudder were not found at the main wreckage site.  The fracture surfaces that were present on the aluminum sheet metal of which the vertical stabilizer and rudder are constructed showed significant tearing and ripping signatures that extended from the leading edge of the horizontal stabilizer aft to the trailing edge of the rudder.

Wreckage Path

The farthest portion of wreckage was found about 1,500 feet west of the main wreckage site of the Cessna 208B. The area was marked by the discovery of portions of the Cessna 208B’s fragmented vertical stabilizer, which included portions of the black rubber leading-edge deicing boot. The flattened portion of the vertical stabilizer’s leading edge had red paint transfers matching that of the wing of the Cessna 207. 

A large portion of the Cessna 207’s severed right aileron was discovered about 1,400 feet west of the Cessna 208B’s wreckage site. Attached to the severely distorted and crushed portion of aileron were portions of structural wing stringers, as well as a small portion of the Cessna 207’s aft main wing spar. The aileron had black rubber smears embedded into the trailing edge.        

The Cessna 208B’s severed rudder and vertical stabilizer were found separately, but close together, about 1,000 feet west of the main wreckage site.  The fracture surfaces on the lower portions of both control surfaces matched those portions still attached to the Cessna 208’s empennage.

Cessna 207:

The wreckage of the Cessna 207 was about 2 miles east of the Cessna 208B’s wreckage site, in an area of hilly, soft, tundra-covered terrain.  With the exception of a large portion of the airplane’s right aileron, all of the airplane's major components were found at the main wreckage site.

The airplane’s right wing trailing edge sustained extensive structural damage during the collision. About 48 inches of the airplane’s right aileron was missing, and the outboard portion right wing flap was crushed and folded inward toward the fuselage.  An 18-inch section of the aft wing spar was fractured and compressed forward about 6 inches beyond the rest of the aft wing spar assembly. The severed portion of wing spar was held into place by only small shreds of aluminum wing skin. The entire outboard section of the right wing was buckled and distorted.

A portion of crushed and distorted wreckage, measuring about 6 inches by 4 inches, was discovered imbedded into the trailing edge of the right wing. The portion of wreckage was painted white, and it had a part number 2631000-16 stamped on the back. The part number was identified as a structural doubler assembly for Cessna 208 airplanes, which is installed on the upper portion of the vertical stabilizer assembly.

MEDICAL AND PATHOLOGICAL INFORMATION

A postmortem examination of the Cessna 208B pilot’s remains was done under the authority of the Alaska State Medical Examiner, Anchorage, on September 6, 2011. However, the report notes that, due to the limited amount of remains presented at the time of the autopsy, the medical examiner’s cause of death was attributed to extensive thermal charring. The report also notes that blunt force injury could not be excluded.  

No toxicological examination was done due to the lack of suitable specimens.


  NTSB Identification: ANC11FA091A
 Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Friday, September 02, 2011 in Nightmute, AK
Aircraft: CESSNA 208B, registration: N207DR
Injuries: 1 Fatal,1 Uninjured.



NTSB Identification: ANC11FA091B

Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Friday, September 02, 2011 in Nightmute, AK
Aircraft: CESSNA T207A, registration: N73789
Injuries: 1 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 September 2, 2011, about 1335 Alaska daylight time, a Cessna 208B (Caravan) airplane, N207DR, and a Cessna 207 airplane, N73789, collided in midair, approximately 9 miles north of Nightmute, Alaska. Both airplanes were being operated as visual flight rules (VFR) charter flights under 14, CFR Part 135, in visual meteorological conditions when the accident occurred. The Cessna 208B was operated by Grant Aviation Inc., Anchorage, Alaska, and the Cessna 207 was operated by Ryan Air, Anchorage, Alaska. The sole occupant of the Cessna 208B, an airline transport pilot, sustained fatal injuries. The sole occupant of the Cessna 207, a commercial pilot, was uninjured. Both airplanes sustained substantial damage during the midair collision. After the collision, the Cessna 208B descended, uncontrolled, and impacted tundra-covered terrain. A postcrash fire consumed most of the wreckage. The Cessna 207 was further damaged during a forced landing on tundra-covered terrain. Both airplanes were based at the Bethel Airport, Bethel, Alaska. The Cessna 208B departed from the Toksook Bay Airport about 1325, and VFR company flight following procedures were in effect for the flight to Bethel. The Cessna 207 departed from the Tununak Airport, Tununak, Alaska, about 1315, and VFR company flight following procedures were in effect for the return flight to Bethel.

During separate telephone conversations with the National Transportation Safety Board (NTSB) investigator-in-charge on September 2, the chief pilot for Ryan Air, as well as the director of operations for Grant Aviation, independently reported that both pilots had a close personal relationship.

During an initial interview with the NTSB IIC on September 3, in Bethel, the pilot of the Cessna 207 reported that both airplanes departed from the neighboring Alaskan villages about the same time, and both airplanes were en route to Bethel along similar flight routes. She said that just after takeoff from Tununak, she talked with the pilot of the Cessna 208B on a prearranged, discreet radio frequency, and the two agreed to rendezvous for the flight back to Bethel. She said that while in cruise level flight at 1,200 feet msl, en route to Bethel, the pilot of the Cessna 208B flew his airplane along the left side of her airplane, and they continued to talk via radio. She said that the pilot of the 208B then unexpectantly and unannounced climbed his airplane above, and overtop of her airplane. She immediately told the pilot of the 208B that she could not see him, and she was concerned about where he was. She said the 208B pilot then said, in part: "Whatever you do, don't pull up." Moments later, the next thing she recalls was the 208B's impact with her airplane's right wing.

The 207 pilot reported that after the impact, she saw the 208B pass underneath her airplane, and it began a gradual descent, which steepened as the airplane continued to the left and away from her airplane. She said that she told the pilot of the 208B that she thought she was going to crash. The pilot of the 208B stated that he also thought he was going to crash. She said that she watched as the 208B continued to descend, then it entered a steep, vertical, nose down descent, before it collided with the ground. She said a postcrash fire started instantaneously upon impact.

The 207 pilot said that while struggling to maintain control of her airplane, she was unable to maintain altitude, and she selected an area of rolling, tundra-covered terrain as a forced landing site. She said that during the emergency descent, she had limited roll control, and the airplane's stall horn was on during the entire emergency approach. The airplane touched down on the soft terrain, and the nose landing gear collapsed.

On September 3, the NTSB IIC, along with an Alaska State Trooper, and a Federal Aviation Administration operations inspector from the Anchorage Flight Standards District Office (FSDO), examined the wreckage sites. The wreckage of the Cessna 207 was located about 1 mile to the east of the Cessna 208B. Both aircraft came to rest in an area of tundra-covered, hilly terrain.

The Cessna 208B's severed vertical stabilizer and rudder assemblies were found about one-half mile west of the main wreckage site, and along the two airplanes' reported flight route. A large portion of the Cessna 207's right aileron was found near the 208's rudder and stabilizer.


The National Transportation Safety Board has released a preliminary report on the Aug. 2 midair collision and plane crash that killed 24-year-old Kenai pilot Scott Veal.
(Courtesy Alaska State Troopers)


ANCHORAGE, Alaska—   A 24-year-old Kenai pilot who died in a Sept. 2 plane crash near Nightmute after a midair collision was flying in formation with his girlfriend when he pulled up over her aircraft without warning, according to a preliminary report from the National Transportation Safety Board.

The report says Scott Veal’s Cessna 208B, operated by Grant Aviation Inc., took off from Toksook Bay at about 1:25 p.m., ten minutes after a Cessna 207 operated by Ryan Air and piloted by his girlfriend, 26-year-old Kristen Sprague of Idaho, took off from Tununak. The pilots were the sole occupants of each aircraft.

Sprague told investigators she and Veal were both headed to Bethel, and they agreed by radio to meet up for the flight at an altitude of 1,200 feet, with Veal flying to Sprague’s left. The two pilots continued to fly in formation, chatting via radio.

At about 1:35 p.m., Veal unexpectedly pulled up and maneuvered his aircraft directly above Sprague’s, causing her to radio Veal that she couldn’t see him and was concerned about where he was. Veal then radioed back, saying in part, “Whatever you do, don’t pull up,” just before his aircraft collided with the right wing of Sprague’s plane.

Veal’s aircraft lost its vertical stabilizer and rudder in the collision, causing his plane to fall below Sprague’s and to the left in a steepening dive. Sprague’s plane lost a large section of its right aileron, and she radioed Veal saying she thought she would crash -- receiving a response that he thought he would crash as well.

As Sprague watched, Veal’s plane plummeted vertically into the ground, where it immediately burst into flames. Although Sprague was still in the air, her plane was losing altitude as she fought to maintain control and she selected an area of rolling tundra for a forced landing. The aircraft’s stall horn was on throughout the approach and the front landing gear collapsed on impact, but Sprague was uninjured.

Investigators found the pieces of both Cessnas lost in the collision about half a mile west of Veal’s crash site, about nine miles north of Nightmute.

The crash is Alaska’s third midair collision this year, following a July 10 incident in Lake Clark Pass after which both planes landed safely and the July 30 accident near Trapper Creek after which one plane crashed, killing a family of four.

NTSB Identification: ANC10LA019
Scheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Wednesday, February 17, 2010 in Kwigillingok, AK
Probable Cause Approval Date: 04/12/2011
Aircraft: CESSNA 208B, registration: N207DR
Injuries: 8 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

Passengers reported that prior to departing on the accident flight they observed ice on the wings and described the weather as foggy, with freezing rain. Shortly after takeoff, at an estimated 200 feet above the ground, the pilot reported a series of power fluctuations, coinciding with a loss of altitude. The pilot stated that he engaged the emergency power lever, and that power was restored, but not before the airplane collided with a frozen lake, damaging the right wing. The airplane subsequently became airborne, and the pilot elected to fly to another village to land.

A postaccident inspection disclosed no mechanical anomalies with the engine or its accessories, and the airplane was flown to its base after the wing was repaired without any engine problems noted. A weather study by a Safety Board meteorologist determined that the area was subject to light snow showers, freezing fog and mist, and surface temperatures below freezing, all conducive to wing/airframe icing. During an interview with Federal Aviation Administration inspectors, the pilot acknowledged seeing “a trace of ice” on the wings. The limitations section of the airplane's flight manual supplement "Known Icing Equipment," states, in part: "Takeoff is prohibited with any frost, ice, snow, or slush adhering to the wings, horizontal stabilizer, vertical stabilizer, control surfaces, proper blades, or engine inlets." The limitations section also includes the following: "WARNING, EVEN SMALL AMOUNTS OF FROST, ICE, SNOW OR SLUSH ON THE WING MAY ADVERSELY CHANGE LIFT AND DRAG. FAILURE TO REMOVE THESE CONTAMINANTS WILL DEGRADE AIRPLANE PERFORMANCE AND MAY PREVENT A SAFE TAKEOFF AND CLIMBOUT."

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot's decision to take off with ice-contaminated wings in freezing rain and mist, which resulted in an aerodynamic stall.


 On February 17, 2010, at 1657 Alaska standard time, a Cessna 208B, N207DR, sustained substantial damage during impact with terrain following takeoff from Kwigillingok Airport (GGV), Kwigillingok, Alaska. The airline transport pilot and his seven passengers were not injured. Grant Aviation, Anchorage, Alaska, was operating the aircraft under the provisions of 14 Code of Federal Regulations Part 135. Visual meteorological conditions prevailed for the flight, which was originating at the time of the accident. The intended destination was Kipnuk, Alaska, and a company flight plan had been filed.

The pilot said that the takeoff was normal, but at 200 feet above the ground and in a turn, he observed a reduction in power. He moved the emergency fuel control lever forward, and power was restored. Before the sink rate could be reversed, the airplane impacted the surface of a frozen lake, and 5 feet of the outboard right wing was bent up. The aileron was not damaged. For safety reasons, the pilot chose to fly straight ahead for 8 miles to Kongiganak, Alaska, where the flight landed without further difficulty.

The operator's maintenance personnel inspected the engine and airframe, and determined that the right wing required a major repair to restore it to an airworthy condition. After a field repair of the right wing by the operator, the Federal Aviation Administration (FAA) granted a ferry permit for a one time flight from Kongiganak to Anchorage. The operator found no discrepancies with the engine, and it operated normally during the ferry flight.

The pilot reported to a FAA inspector that the cloud condition was 500 feet overcast with 2.5 miles visibility in light snow. There was a light wind from the north at approximately 3 to 5 knots. When the inspector asked the pilot if the airplane had ice on it when it departed Kwigillingok, he stated that there was a "trace" of ice on the wings. When interviewed by the FAA inspector, passengers made the following statements:

1. "There was freezing rain."

2. "The plane was iced up and when it took off it stalled."

3. "The weather was icing rain….There was some ice on the wings before they took off from Kwigillingok."

There was no weather reporting facility at Kwigillingok. The closest weather reporting station was at Kipnuk, Alaska, about 26 nautical miles west of the accident site. At 1656, the reported conditions were: wind 050 degrees at 7 knots; visibility 10 statute miles; cloud condition, broken at 400 feet, overcast at 3,300 feet; temperature 23 degrees Fahrenheit; dew point 23 degrees Fahrenheit; altimeter setting 29.67 inches of Mercury. The pilot told the National Transportation Safety Board's (NTSB) investigator-in-charge that the cloud condition was an indefinite ceiling at 500 to 600 feet with light snow, and the temperature was 30 degrees Fahrenheit. An NTSB meteorologist did a weather study and found that the area was subject to light snow showers, freezing fog and mist, and ground temperatures were below freezing.

The limitations section of the Cessna 208B flight manual supplement "Known Icing Equipment," states, in part: "Takeoff is prohibited with any frost, ice, snow, or slush adhering to the wings, horizontal stabilizer, vertical stabilizer, control surfaces, proper blades, or engine inlets." The limitations section also includes the following: "WARNING, EVEN SMALL AMOUNTS OF FROST, ICE, SNOW OR SLUSH ON THE WING MAY ADVERSELY CHANGE LIFT AND DRAG. FAILURE TO REMOVE THESE CONTAMINANTS WILL DEGRADE AIRPLANE PERFORMANCE AND MAY PREVENT A SAFE TAKEOFF AND CLIMBOUT."