# NTSB ANC93LA071: Cessna 185, N80124, Bulchitna Lake, AK, May 29, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 28, 1993, 17:15 local (May 29, 1993, 01:15 UTC) - Place: Bulchitna Lake, AK - Coordinates: 61.929893, -151.729675 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.9299&lon=-151.7297&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report June 30, 1994 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2344 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC93LA071 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2344/pdf - Page: https://openairdocs.org/ntsb/ANC93LA071 ## Probable cause THE FAILURE OF THE LANDING GEAR LEG DUE TO A FATIGUE FRACTURE CAUSED BY CORROSION. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - Main gear collapsed, landing - flare/touchdown - landing gear,main gear - corroded (cause) - landing gear,main gear - fatigue (cause) - Nose over, landing - roll ## Analysis THE PILOT-IN-COMMAND STATED HE EXPERIENCED A MODERATELY HARD LANDING AND THE RIGHT MAIN WHEEL SEPARATED FROM THE LANDING GEAR AT THE UPPER BOLT HOLES WHICH NORMALLY SECURE THE AXLE TO THE LANDING GEAR LEG. METALLURGICAL EXAMINATION OF THE GEAR LEG SHOWED THAT THE FAILURE STEMMED FROM AREA OF FATIGUE CRACKING THAT INITIATED FROM CROSSION PITTING IN THE BOLT HOLES AND EXTERIOR SURFACES OF THE LOWER PORTION OF THE GEAR LEG. ## Factual narrative On May 28, 1993, at 1715 Alaska daylight time, a wheel equipped Cessna 185 airplane, N80124, registered to and operated by the Pilot-in-Command, experienced a hard landing and subsequant landing gear failure at Sigley's private Airstrip located near Bulchitna Lake, Alaska. The business flight, operating under 14 CFR Part 91, last departed Kenai, Alaska, and the destination was the accident site. Visual meteorological conditions prevailed and no flight plan was filed. The airplane was substantially damaged and the Commercially Certificated Pilot-in-Command and the two passengers were not injured. According to the Pilot-in-Command, he experienced a moderate hard landing and the right main gear broke away at the wheel axle upper bolt holes. The airplane settled onto the remaining gear leg, veered right, and nosed over. Metallurigical examination of the fractured gear leg showed that the separation of the landing gear leg stemmed from areas of fatigue cracking that initiated from corrosion pitting in the bolt holes and exterior surfaces of the lower portion of the leg. Further, the metallurgist stated that the gear leg was composed of high strength steel, a material that is susceptible to fracture in the presence of relatively small defects. ## Aircraft - Registration: [N80124](https://openairdocs.org/aircraft/N80124), registered now, S/N 18503094 (OpenAirDocs) - Reported make and model: CESSNA 185 - Registry model: [Cessna A185F](https://openairdocs.org/model/cessna-a185f) (registry code 2072821) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18503094 - Airframe hours: 5826 - Engines: Continental IO-520-F 300 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Operator: White, Carl H., doing business as White'S Air Service - Registered owner: White, Carl H. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 19, 1993, 65 hours before - Departed: ENA, KENAI, AK - Airport: Sigley'S Pvt Airstrip, runway 36, 1,100 × 30 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 3,761 total, 3,100 in this make and model, 3,637 as pilot in command, 68 in the last 90 days, 21 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Visibility: 70 statute miles - Lowest ceiling: none - Temperature: 70 °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 19930528016139A](https://openairdocs.org/incident/19930528016139A), May 28, 1993: Cessna A185F, Bulchitna Lake, AK, Substantial damage. Moderate hard landing caused right gear to break at axle. Nosed over. Fatigue cracking due bolt hole corrision. ## Other investigations on N80124 (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 ANC85LA177](https://openairdocs.org/ntsb/ANC85LA177), Sep 15, 1985: Cessna A185F (N80124), Cordova, AK, substantial damage - [NTSB ANC82DA087](https://openairdocs.org/ntsb/ANC82DA087), Sep 9, 1982: Cessna 185F (N80124), Naknek, AK, 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.