Accident Details
Probable Cause and Findings
THE WORN CAM SHAFT LOBE AND WORN VALVE LIFTER.
Aircraft Information
Registered Owner (Current)
Analysis
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.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ANC94LA129