# NTSB ANC95LA053: Cessna 170B, N4366B, Chickaloon, AK, May 12, 1995 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 11, 1995, 17:15 local (May 12, 1995, 01:15 UTC) - Place: Chickaloon, AK - Coordinates: 61.740409, -148.220306 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.7404&lon=-148.2203&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report November 8, 1995 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2648 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC95LA053 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2648/pdf - Page: https://openairdocs.org/ntsb/ANC95LA053 ## Probable cause THE FRACTURE OF THE CRANKSHAFT RESULTING IN SEPARATION OF THE PROPELLER AND PROPELLER FLANGE IN-FLIGHT. A FACTOR ASSOCIATED WITH THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN FOR AN EMERGENCY 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 - engine assembly,crankshaft - separation (cause) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, emergency descent/landing - terrain condition - none suitable (contributing factor) ## Analysis THE PILOT REPORTED THE AIRPLANE'S PROPELLER, PROPELLER FLANGE AND A PORTION OF THE CRANKSHAFT SEPARATED FROM THE AIRPLANE WHILE CRUISING AT AN ALTITUDE OF 6,500' MSL. HE SAID THE ONLY AVAILABLE LANDING SITE WAS A NARROW ROAD, AND THAT HE WAS FORCED BY SURROUNDING TERRAIN TO LAND UPHILL AND DOWNWIND. THE AIRPLANE LANDED HARD, WENT OFF THE ROAD AND INTO A DITCH. THE MISSING PROPELLER AND COMPONENTS WERE NOT RECOVERED. ## Factual narrative On May 11, 1995, about 1715 Alaska daylight time, a wheel equipped Cessna 170B airplane, N4366B, sustained substantial damage during a forced landing onto Alaska State Highway 1, near Chickaloon, Alaska. The solo private pilot was not injured. The 14 CFR Part 91 cross country flight operated in visual meteorological conditions. The flight departed Northway, Alaska, about 1500. The pilot reported that while in cruise flight at 6,500' msl, the engine began to vibrate abruptly, followed almost immediately by a loud noise and the separation of the propeller from the engine. He said the only suitable forced landing area was the highway, and he was forced to land downwind and uphill due to surrounding terrain. The airplane bounced, and went into a ditch adjacent to the highway. The pilot could give no reason why the propeller separated from the engine. In his written statement to the NTSB, he noted that the propeller, the propeller mounting flange, and the forward portion of the crankshaft had separated from the engine and were not recovered. ## Aircraft - Registration: [N4366B](https://openairdocs.org/aircraft/N4366B), registered now, S/N 26710, built 1955 (OpenAirDocs) - Reported make and model: CESSNA 170B - Registry model: [Cessna 170B](https://openairdocs.org/model/cessna-170b) (registry code 2072306) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 26710 - Airframe hours: 3404 - Engines: LYCOMING O-360-A1A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: William F. Parnell - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: Annual, April 13, 1995, 44 hours before - Departed: ORT, NORTHWAY, AK - Destination: SQX, SOLDOTNA, AK - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; private; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 1,445 total, 445 in this make and model, 1,390 as pilot in command, 48 in the last 90 days, 48 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 20 knots - Visibility: 35 statute miles - Lowest ceiling: none - Temperature: 55 °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 19950511010949A](https://openairdocs.org/incident/19950511010949A), May 11, 1995: Cessna 170B, Chickaloon, AK, Substantial damage. Rough engine and prop separated at cruise. Landed on highway bounced into ditch. Forward part crankshaft also gone. 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.