# NTSB ANC96TA095: Cessna 185, N185CA, Fairbanks, AK, July 4, 1996 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Final report - Date: July 4, 1996, 14:05 local (22:05 UTC) - Place: Fairbanks, AK - Coordinates: 64.809906, -147.72026 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=64.8099&lon=-147.7203&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report August 29, 1997 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2922 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC96TA095 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2922/pdf - Page: https://openairdocs.org/ntsb/ANC96TA095 ## Probable cause fatigue failure of the engine crankshaft. A factor related to the accident was: the lack of suitable terrain for a forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - normal - engine assembly,crankshaft - fatigue (cause) - Forced landing, emergency descent/landing - In flight collision with terrain/water, emergency landing - terrain condition - none suitable (contributing factor) - terrain condition - tundra ## Analysis The pilot was in cruise flight over mountainous terrain in a float equipped airplane. The engine suddenly lost power, and the pilot performed an emergency landing on tundra covered terrain. During the landing, the airplane floats dug into the tundra, and the airplane turned completely over. A postaccident examination of the engine revealed a fatigue failure of the crankshaft. ## Factual narrative On July 4, 1996, about 1405 Alaska daylight time, a float equipped Cessna 185, N185CA, crashed during a forced landing, about 35 miles north of Fairbanks, Alaska. The airplane was being operated as a visual flight rules (VFR) local area government flight under Title 14 CFR Part 91 when the accident occurred. The airplane, registered to the U.S. Department of the Interior and operated by the U.S. Fish and Wildlife Service, was destroyed. The certificated commercial pilot, the sole occupant, received minor injuries. Visual meteorological conditions prevailed. A VFR flight plan was filed. The flight originated at the Fairbanks International airport, at 1300. The pilot reported that he was in cruise flight at 5,500 feet mean sea level (msl) over mountainous terrain that was about 4,000 feet high. He indicated that he heard a slight change in the engine sound and then it suddenly lost power. The pilot made a radio "mayday" call and began emergency procedures in an attempt to restore engine power. None were successful and the engine propeller completely stopped. The pilot performed an emergency landing in a previously burned area of tundra and muskeg. During the landing, the airplane's right float assembly dug into the ground and the airplane nosed completely over, coming to rest upright on the damaged floats. After recovery, the engine was examined on July 18, 1996, in Anchorage, Alaska, at the Department of Interior maintenance hanger. The examination revealed metal particles in the oil filter. Metal flakes and scoring were noted in the oil pump. Removal of the oil sump revealed pieces of metal and bearing material in the bottom of the sump. One of the number 2 connecting rod bearing cap bolts was sheared near the head of the bolt. The nut and cotter pin were still attached to the separated segment of bolt. The crankshaft, serial number 1289007N, was separated at the number 3 crankshaft cheek between the number 2 main bearing and the number 2 cylinder rod bearing. The number 2 main bearing saddle on each half of the engine case was distorted and flattened. The bearing was distorted and flattened. Small portions along the edges of the bearing were broken and located in the oil sump. Examination of the engine maintenance records revealed it was rebuilt by Teledyne Continental Motors, Mobile, Alabama, on December 11, 1990. The engine, an IO-520-D, serial number 282598-R, was installed in the accident airplane on April 18, 1991. At the time of the accident, the engine had accrued 1,449.3 hours of operation since the rebuild. On September 13, 1994, 1,040 hours since the engine was rebuilt and 409 hours before the accident, the number 1, 2, and 5 cylinders were replaced. The last annual inspection on the engine and airframe was conducted on June 7, 1996, 33 hours prior to the accident. The crankshaft was submitted to the National Transportation Safety Board, Materials Laboratory, Washington, D.C., for examination. The laboratory reported the crankshaft exhibited features typical of a fatigue crack emanating from multiple origins along the aft radius of the number 2 main journal. ## Aircraft - Registration: [N185CA](https://openairdocs.org/aircraft/N185CA), registered now, S/N 18504445, built 1985 (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: 18504445 - Airframe hours: 3082 - Engines: Continental IO-520-D 300 horsepower reciprocating - Damage: Destroyed - Flight: Public aircraft, Part 91 - Operator: U.S. Fish And Wildlife Service - Registered owner: U.S. Department Of Interior - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 7, 1996, 33 hours before - Departed: FAI, AK - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; commercial, flight instructor; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 6,700 total, 3,500 in this make and model, 6,500 as pilot in command, 200 in the last 90 days, 110 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 100 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 19960704015989A](https://openairdocs.org/incident/19960704015989A), Jul 4, 1996: Cessna A185F, Fairbanks, AK, Destroyed. Lost power at cruise. Force landed on thundra. Float dug in. Flipped over. Broke crankshaft. Fatigue cracking. 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.