# NTSB ANC05LA133: Cessna 206, N4991F, Yakutat, AK, September 2, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 1, 2005, 17:00 local (Sep 2, 2005, 01:00 UTC) - Place: Yakutat, AK - Coordinates: 59.12611, -138.406951 - Nearby events: https://openairdocs.org/map.md?lat=59.1261&lon=-138.4070&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report June 28, 2006 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA-AL JNU FSDO 05 - NTSB case key (mKey): 62400 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC05LA133 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/62400/pdf - Page: https://openairdocs.org/ntsb/ANC05LA133 ## Probable cause The pilot's selection of unsuitable terrain for takeoff, and his failure to maintain adequate airspeed during takeoff initial climb from a remote airstrip, which resulted in the airplane descending to the ground and colliding with soft terrain beyond the end of the airstrip. Factors contributing to the accident were the rough/uneven airstrip surface consisting of humps and rocks, and an inadvertent stall/mush. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, takeoff - initial climb - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause) - terrain condition - rough/uneven (contributing factor) - airspeed(vs) - not maintained, pilot in command (cause) - stall/mush - inadvertent, pilot in command - climb - not attained, pilot in command - In flight collision with terrain/water, descent - uncontrolled - terrain condition - soft - terrain condition - water ## Analysis The airline transport certificated pilot, with four passengers, fishing equipment, and a dog aboard, were departing on a personal flight from a remote gravel airstrip that was 1,100 feet long and 10 feet wide. The FAA's Airport/Facility Directory, Alaska Supplement listing for the airstrip includes "...dips and humps 8 to 12 inches entire length. Rocks on surface to 3 inches. Runway used as a road." The pilot told the NTSB investigator-in-charge (IIC) that during the takeoff roll, the airplane became airborne in ground effect, but the engine power rapidly decreased, and the airplane settled into about 12 inches of water in a tidal zone. The pilot indicated that the airplane had flown through heavy rain in the previous four days, but he had not encountered any problems until the accident takeoff. The airplane received structural damage to the right wingtip and right wing root. An FAA inspector interviewed the pilot and passengers, and reported that the pilot told him the airplane became airborne after hitting some bumps about 2/3 of the way down the runway. The pilot said he attempted to keep the airplane airborne in ground effect, but it settled to the soft ground beyond the end of the runway in high grass and water. Based on his interviews, the inspector estimated that the airplane was within 100 pounds of its gross weight limit. The inspector indicated that air taxi operators in the local area only use the airstrip while carrying a reduced load due to the condition of the airstrip surface. Sufficient structural and propeller repairs were made to the airplane at the accident scene allowing it to be flown out by recovery personnel, and they did not report any engine problems. ## Factual narrative On September 1, 2005, about 1700 Alaska daylight time, a wheel-equipped Cessna 206 airplane, N4991F, sustained substantial damage when it collided with soft terrain in a tidal area during takeoff initial climb from a remote airstrip, about 45 miles east of Yakutat, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) local area personal flight under Title 14, CFR Part 91, when the accident occurred. The airline transport certificated pilot and the four passengers were not injured. Visual meteorological conditions prevailed. The flight originated at the East Alsek River airstrip, and was en route to the Tanis Mesa airstrip. No flight plan was filed. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on September 2, the pilot reported that he was departing on runway 20 from the gravel surfaced East Alsek River airstrip, which is 1,100 feet long, and 10 feet wide. The pilot said that during the takeoff roll, the airplane became airborne in ground effect, but the engine power rapidly decreased, and the airplane settled into about 12 inches of water in the tidal zone of the East Alsek River. During the touchdown, the right main landing gear dug into the soft sand, spinning the airplane to the right. The propeller and right wingtip struck the ground. The pilot indicated that the airplane had flown through heavy rain in the previous four days, but he had not encountered any problems until the accident takeoff. The airplane received structural damage to the right wingtip and right wing root. The FAA's Airport/Facility Directory, Alaska Supplement listing for the airstrip states, in part: "Unattended. Runway 02-20 [has] dips and humps 8 to 12 inches entire length. Rocks on surface to 3 inches. Runway used as a road." On September 12, recovery personnel reported via telephone that sufficient airframe and propeller repairs were made to the airplane at the accident site, and it was flown to Anchorage, Alaska. On January 11, 2006, recovery personnel stated that no engine problems were encountered during the recovery process. The pilot was sent a Pilot/Operator Aircraft Accident Report (NTSB form 6120.1) on September 7, but the form was not received at the NTSB's Alaska Regional Office, Anchorage. During a telephone conversation with the NTSB IIC on December 13, the pilot reported that he mailed the form. A second NTSB Form 6120.1 was sent to the pilot on December 13, but was not received at the NTSB's Alaska Regional Office. An FAA Air Safety Inspector, Juneau Flight Standards District Office, Juneau, Alaska, interviewed the pilot and passengers. The inspector reported that the pilot told him the airplane became airborne after hitting some bumps about 2/3 of the way down the runway. The pilot said he attempted to keep the airplane airborne in ground effect, but it settled to the ground beyond the end of the runway in high grass and water. Based on his interviews, the inspector estimated that the airplane was within 100 pounds of its gross weight limit with the pilot and passengers, fishing equipment, and a dog aboard. The airplane was not equipped with oversize tires. The inspector indicated that air taxi operators in the local area only use the airstrip while carrying a reduced amount of load due to the condition of the airstrip surface. ## Aircraft - Registration: [N4991F](https://openairdocs.org/aircraft/N4991F), registered now, S/N U206-0691, built 1966 (OpenAirDocs) - Reported make and model: Cessna 206 - Registry model: [Cessna TU206B](https://openairdocs.org/model/cessna-tu206b) (registry code 2073324) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: U2060691 - Engines: Continental IO-520 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Christopher P. Chouinard - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 1, 2004 - Departed: AK76, Yakutat, AK - Destination: A69, Yakutat, AK - Airport: AK76, East Alsek River, runway 20, 1,100 × 10 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; private, airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; seat: left; flight hours: 11,600 total ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20050901024419A](https://openairdocs.org/incident/20050901024419A), Sep 1, 2005: Cessna TU206B, Yakutat, AK, Substantial damage. (-23) Pilot stated that during attempted take off aircraft became airborne after hitting some bumps about 2/3RDS of the way down runway. He tried to keep it… ## Other investigations on N4991F (2) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB LAX82DA288](https://openairdocs.org/ntsb/LAX82DA288), Aug 3, 1982: Cessna U206B (N4991F), Grass Valley, CA, substantial damage - [NTSB OAK74FVD08](https://openairdocs.org/ntsb/OAK74FVD08), Sep 3, 1973: Cessna TU206B (N4991F), Livermore, CA, substantial damage From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.