ANC94LA129

NTSB accident investigation · Piper PA-18 · Tok, AK · September 2, 1994

Accident · No injuriesLimited investigationFinal report
Date
September 2, 1994, 11:26 local (19:26 UTC)
Place
Tok, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N8597DPiper PA-18
Weather
Visual (VMC) · Day
Status
Completed · report May 10, 1995
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
19940902025489A
Case key
2561

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The worn cam shaft lobe and worn valve lifter.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(partial) - mech failure/malfTakeoff - initial climb
Engine assembly,camshaft - wornCause
Engine assembly,valve lifter - wornCause
In flight collision with terrain/waterTakeoff - 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
Reported as
Piper PA-18
Category
Airplane
Serial number
18-6248
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
31
Certificate
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.

Other investigations on N8597D · 4

Matched to the same aircraft by N-number and date.