# NTSB ANC05LA125: Cessna U206E, N9138M, Skwentna, AK, August 21, 2005 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 21, 2005, 13:00 local (21:00 UTC) - Place: Skwentna, AK - Coordinates: 62.051387, -151.437225 - Nearby events: https://openairdocs.org/map.md?lat=62.0514&lon=-151.4372&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor, 3 uninjured - Status: Completed, report March 28, 2006 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Anchorage FSDO-03 - NTSB case key (mKey): 62290 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC05LA125 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/62290/pdf - Page: https://openairdocs.org/ntsb/ANC05LA125 ## Probable cause The pilot's misjudged distance/altitude on final approach, which resulted in a noseover following an undershoot and in-flight collision with rough/uneven terrain. A factor associated with the accident was the rough/uneven terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Undershoot, approach - vfr pattern - final approach - distance/altitude - misjudged, pilot in command (cause) - In flight collision with terrain/water, approach - vfr pattern - final approach - terrain condition - rough/uneven (contributing factor) - Nose over, landing - roll ## Analysis The commercial pilot was conducting a 14 CFR Part 135 on-demand passenger flight to a remote, dirt airstrip at a lodge, when he said the airplane began to sink rapidly on final approach. The pilot said he added power, but the airplane touched down short of the runway, collided with a stump, and came to rest inverted. He said there were no known mechanical anomalies with the airplane prior to the accident, but felt the throttle may not have responded appropriately when he added throttle to arrest the descent rate. After deplaning the passengers, the pilot returned to the airplane and checked the throttle, which appeared to function normally. The airplane received structural damage to the wings and fuselage. ## Factual narrative On August 21, 2005, about 1300 Alaska daylight time, a Cessna U206E airplane, N9138M, sustained substantial damage during an in-flight collision with terrain on final approach to a dirt airstrip, about 10 miles north-northwest of Skwentna, Alaska. The airplane was being operated by Alaska Air Taxi LLC, Anchorage, Alaska, as a visual flight rules (VFR) on-demand passenger flight under Title 14, CFR Part 135 when the accident occurred. The commercial certificated pilot and one passenger received minor injuries; the three other passengers were not injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The flight departed Lake Hood Strip, Anchorage, about 1210. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on August 21, the director of operations for the operator said that the pilot reported that the airplane touched down several hundred feet short of the landing area. He said the area where the airplane touched down had been cleared of trees, but the stumps were still there. He said the pilot told him the airplane hit a stump and nosed over, coming to rest inverted. He said the wings, fuselage, and empennage of the airplane were structurally damaged. During a telephone conversation with the NTSB IIC on August 22, the pilot said he was on short final when the airplane started to sink rapidly. He said he added power, but the airplane touched down short of the runway, and collided with a stump. He said there were no known mechanical anomalies with the airplane prior to the accident. In a written statement to the NTSB dated August 31, the pilot wrote that when he applied the throttle to arrest the descent, he felt that the throttle did not respond appropriately. He said after the passengers deplaned, he returned to the airplane to check the throttle, but it appeared to function normally. ## Aircraft - Registration: [N9138M](https://openairdocs.org/deregistered/N9138M-2006-09-28), registration cancelled 2006-09-28, S/N U20601538, built 1970 (OpenAirDocs) - Reported make and model: Cessna U206E - Registry model: [Cessna U206E](https://openairdocs.org/model/cessna-u206e) (registry code 2073350) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: U20601538 - Airframe hours: 6798 - Engines: Continental IO-520F 300 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Registered owner: Alaska Air Taxi LLC - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: 100 hour, August 1, 2005, 22 hours before - Departed: Z41, Lake Hood Strip, AK - Destination: Skwentna, AK - Flight plan: Company VFR - Airport: Lake Marie Lodge ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; injuries: minor; flight instructor, commercial; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review May 1, 2005; seat: left; flight hours: 1,094 total, 210 in this make and model, 1,036 as pilot in command, 184 in the last 90 days, 61 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none ## 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 20050821022919A](https://openairdocs.org/incident/20050821022919A), Aug 21, 2005: Cessna U206E, Skwentna, AK, Substantial damage. (-23) Aircraft N9138M was on short final to the runway on a stabilized approach when the aircraft encountered a down draft causing the aircraft to hit the… ## Other investigations on N9138M (1) 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 ANC93LA009](https://openairdocs.org/ntsb/ANC93LA009), Oct 23, 1992: Cessna 206 (N9138M), Slate Creek, AK, substantial damage. Probable cause: THE ICY CONDITION OF THE RUNWAY AND THE DISCONTINUED SNOW REMOVAL. 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.