# NTSB ANC94LA129: Piper PA-18, N8597D, Tok, AK, September 2, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 2, 1994, 11:26 local (19:26 UTC) - Place: Tok, AK - Coordinates: 63.179012, -143.100082 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=63.1790&lon=-143.1001&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 10, 1995 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2561 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC94LA129 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2561/pdf - Page: https://openairdocs.org/ntsb/ANC94LA129 ## Probable cause THE WORN CAM SHAFT LOBE AND WORN VALVE LIFTER. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, takeoff - initial climb - engine assembly,camshaft - worn (cause) - engine assembly,valve lifter - worn (cause) - In flight collision with terrain/water, takeoff - initial climb ## Analysis AS THE AIRPLANE REACHED THE END OF THE 600-FT STRIP, THE PILOT APPLIED THE SECOND NOTCH OF FLAPS. THE AIRPLANE BECAME AIRBORNE FOR ABOUT 20 FT, AND THEN SETTLED INTO BRUSH. THE PASSENGER REPORTED THAT 'MY IMPRESSION IS THAT WE LACKED OR LOST ADEQUATE POWER TO MAINTAIN FLIGHT...' ANOTHER COMPANY PA-18 AT SITE HAD NO DIFFICULTY IN FERRYING EVERYONE FROM THE SITE. EXAMINATION OF THE ENGINE SHOWED THAT AN EXHAUST CAM LOBE WAS 30-40% WORN, AND THE ASSOCIATED CAM FOLLOWER WAS WORN AND DISH SHAPED. THE DEPTH OF THE WORN AREAS EXCEEDED THE DEPTH OF THE NITRATED SURFACE. ACCORDING TO THE DIR OF MAINT, A 50-HR INSPECTION WAS PERFORMED PREVIOUS TO THIS FLIGHT AND METAL PARTICLES WERE FOUND IN THE OIL SCREEN. ## Factual narrative On September 2, 1994, at 1126 Alaska daylight time, a wheel equipped Piper PA-18 airplane, N8597D, registered to the pilot, and operated by 40 Mile Air Ltd., of Tok, Alaska, crashed beyond the departure end of an airstrip during a takeoff attempt. The air taxi flight, operating under 14 CFR Part 135, was departing the accident site, which is located 24 nautical miles southwest of Tok on Natahona Creek, and the destination was Tok. A VFR flight plan was filed and visual meteorological conditions prevailed. The pilot and the passenger were not injured and the airplane was substantially damaged. According to the pilot, during an interview with FAA Inspector Steve Ketzer, he did not perform a engine run up because of the gravel and he did not check nor did he use carburetor heat prior to take off. The pilot stated that when he reached the end of the 600 foot long airstrip he applied a second notch of flaps and the airplane became airborne. The airplane then settled and the wheels struck some brush and the airplane crashed. The pilot could not recall the airspeed or the engine tachometer readings during the take off roll. Examination of the engine showed that one of the exhaust cam lodes on the camshaft was 30 to 40 percent worn and the cam follower was worn and dish shaped. According to Randy Rallo, Director of Maintenance for 40 Mile Air LTD., previous to this flight they performed a 50 hour inspection on the airplane and found metal particles in the oil screen. He further stated the wear on the cam lobe and cam follower went beyond the nitrated surface. Another PA-18, a company airplane, was also on the airstrip and had no difficulty in ferrying everyone from the accident site. ## Aircraft - Registration: [N8597D](https://openairdocs.org/aircraft/N8597D), registered now, S/N 18-6248, built 1957 (OpenAirDocs) - Reported make and model: PIPER PA-18 - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-6248 - Engines: LYCOMING O-320-A2B 150 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: 40 Mile Air, Ltd. - Registered owner: Leif L. Wilson - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 12, 1994, 48 hours before - Destination: TKJ, AK - Flight plan: VFR - Airport: Natahona Creek, runway 27, 600 × 10 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 865 total, 410 in this make and model, 835 as pilot in command, 165 in the last 90 days, 135 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 3 statute miles - Lowest ceiling: 4,500 ft overcast - Temperature: 34 °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 19940902025489A](https://openairdocs.org/incident/19940902025489A), Sep 2, 1994: Piper PA18, Tok, AK, Substantial damage. Settled after early liftoff from remote strip. Camshaft 40 percent worn. Prior metal in screens. Poor maintenance. ## Other investigations on N8597D (4) 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 ANC06CA115](https://openairdocs.org/ntsb/ANC06CA115), Aug 16, 2006: Piper PA-18 (N8597D), Tok, AK, substantial damage. Probable cause: The pilot's failure to compensate for the wind conditions during the takeoff roll, which resulted in a collision with a tree. A factor contributing to the accident was a crosswind. - [NTSB ANC04LA096](https://openairdocs.org/ntsb/ANC04LA096), Aug 26, 2004: Piper PA-18 (N8597D), Paxson, AK, substantial damage. Probable cause: The pilot's selection of unsuitable terrain for landing, which resulted in a collision with a rock and subsequent main landing gear collapse during the landing roll. A factor contributing to the… - [NTSB ANC03CA110](https://openairdocs.org/ntsb/ANC03CA110), Sep 7, 2003: Piper PA-18-180 (N8597D), Eagle, AK, substantial damage. Probable cause: The pilot's selection of an unsuitable landing area, and his excessive use of the airplane's brakes during the landing roll, resulting in a nose over. A factor associated with the accident was rough… - [NTSB ANC86LA072](https://openairdocs.org/ntsb/ANC86LA072), Jun 12, 1986: Piper PA-18 (N8597D), Fairbanks, 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.