# NTSB ANC05LA018: Piper PA-28-140, N801FS, Sleetmute, AK, December 14, 2004 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: December 14, 2004, 16:00 local (20:00 UTC) - Place: Sleetmute, AK - Coordinates: 61.083332, -156.899993 - Nearby events: https://openairdocs.org/map.md?lat=61.0833&lon=-156.9000&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 3 minor - Status: Completed, report December 20, 2005 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 60809 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC05LA018 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/60809/pdf - Page: https://openairdocs.org/ntsb/ANC05LA018 ## Probable cause A loss of engine power during cruise flight due to a fractured exhaust valve, which resulted in a forced landing, and subsequent nose over of the airplane. A factor associated with the accident was the lack of suitable terrain for a successful emergency landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - normal - engine assembly,valve,exhaust - fractured (cause) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, emergency landing - terrain condition - none suitable (contributing factor) - Nose gear collapsed, landing - roll - terrain condition - snow covered - Nose over, landing - roll ## Analysis The commercial certificated pilot reported that while the airplane was in level cruise flight at 5,000 msl, he noted a rough running engine and a slight reduction in engine rpm, which was followed by a rapid loss of engine power, and subsequent loss of altitude. He was unable to restore adequate engine power to maintain level flight, and selected a snow-covered area as a forced landing site. During the landing roll, the airplane's nose landing gear collapsed, and the airplane nosed over. The airplane sustained structural damage to the wings and fuselage. An FAA inspector reported that during his inspection of the accident airplane's engine, he discovered that a significant portion of the exhaust valve had broken free from the exhaust valve stem in the number 1 cylinder. He stated that the broken portion of the valve subsequently entered the number 1 cylinder combustion chamber and damaged the piston. ## Factual narrative On December 14, 2004, about 1600 Alaska standard time, a wheel-equipped Piper PA-28-140 airplane, N801FS, sustained substantial damage during an off airport forced landing following a loss of engine power, about 35 miles southeast of Sleetmute, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight under Title 14, CFR Part 91, when the accident occurred. The commercial certificated pilot and the two passengers sustained minor injuries. Visual meteorological conditions prevailed, and a VFR flight plan was in effect. The flight originated about 1335, from the Lake Hood Airstrip, Anchorage, Alaska, and was en route to Bethel, Alaska, when the accident occurred. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on December 19, 2004, the pilot related that he had to alter his intended flight path slightly due to low weather conditions along his route. He said that while the airplane was in level cruise flight at 5,000 msl, he noted a rough running engine and a slight reduction in engine rpm. He said that emergency procedures did not remedy the engine roughness, which was followed by a rapid loss of engine power, and subsequent loss of altitude. The pilot said that he was unable to restore adequate engine power to maintain level flight, and he selected a snow-covered area as a forced landing site. During the landing roll on the soft, snow-covered terrain, the airplane's nose landing gear collapsed, and the airplane nosed over. The airplane sustained structural damage to the wings and fuselage. A Federal Aviation Administration (FAA) airworthiness inspector from the Anchorage Flight Standards District Office (FSDO), traveled to Bethel after the airplane had been recovered from the remote accident site. During a telephone conversation with the NTSB IIC on September 7, 2005, the FAA inspector reported that during his inspection of the accident airplane's engine, and after removing the number 1 cylinder from the engine crankcase, he discovered that a significant portion of the exhaust valve had broken free from the exhaust valve stem. He stated that the broken portion of the valve subsequently entered the number 1 cylinder combustion chamber. The number 1 piston sustained significant amount of damage, including a large hole in the top portion of the piston assembly. ## Aircraft - Registration: [N801FS](https://openairdocs.org/aircraft/N801FS), registered now, S/N 28-7125090, built 1970 (OpenAirDocs) - Reported make and model: Piper PA-28-140 - Registry model: [Piper PA-28-140](https://openairdocs.org/model/piper-pa-28-140) (registry code 7102802) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28-7125090 - Airframe hours: 1968.1 - Engines: Lycoming O-320-E2A 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Garis Kinegak - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 1, 2004, 102 hours before - Departed: Z41, Anchorage, AK - Destination: BET, Bethel, AK - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: minor; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review October 1, 2003; seat: left; flight hours: 542 total, 78 in this make and model, 471 as pilot in command, 116 in the last 90 days, 36 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 30 °F 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.