ANC01LA116

NTSB accident investigation · Piper PA-18 · Anaktuvuk Pass, AK · August 6, 2001

Accident · No injuriesLimited investigationFinal report
Date
August 6, 2001, 14:00 local (22:00 UTC)
Place
Anaktuvuk Pass, AK
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N4167ZPiper PA-18
Weather
Visual (VMC) · Day
Status
Completed · report February 20, 2002
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA-AL-FAI FSDO 01
FAA report
20010806020259A
Case key
53078

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

A failure of the landing gear strut assembly due to corrosion. A factor in the accident was the pilot's inadequate maintenance of the airplane.

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.

Airframe/component/system failure/malfunctionLanding - flare/touchdown
Landing gear,main gear strut - corrodedCause
Maintenance - inadequatePilot in commandFactor
On ground/water encounter with terrain/waterLanding - flare/touchdown
Terrain condition - rock(s)/boulder(s)

Analysis

The commercial certificated pilot was landing at a remote airstrip. When the airplane touched down, the right main landing gear strut collapsed. The propeller struck the ground, and the leading edge of the right wing struck a large rock. The pilot activated the airplane's emergency locator transmitter, and a search and rescue helicopter picked up the pilot. A postaccident examination of the airplane revealed extensive corrosion of the landing gear strut.

Factual narrative

On August 6, 2001, about 1400 Alaska daylight time, a tundra tire-equipped Piper PA-18 airplane, N4167Z, sustained substantial damage during a landing at a remote airstrip near Gunsight Mountain, located about 35 miles north-northeast of Anaktuvuk Pass, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country business flight under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by Arctic North Guiding Inc., North Pole, Alaska. The commercial certificated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed.

The Federal Aviation Administration (FAA) notified the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on August 6th, that an emergency transmitter locator (ELT) signal had been detected north of the Brooks Mountain Range. A search and rescue helicopter from the North Slope Borough, Barrow, Alaska, responded to the scene and picked up the pilot. The pilot was taken by the helicopter to the pilot's hunting camp. The helicopter crew reported the pilot made a hard landing, and the airplane received damage to the right landing gear strut assembly, the propeller, and the leading edge of the right wing.

An FAA inspector, Fairbanks Flight Standards District Office (FSDO), reported that after temporary repairs by a mechanic, the airplane was flown to Fairbanks, Alaska. The inspector examined the airplane on August 20, and reported the landing gear strut assembly had evidence of extensive corrosion. The inspector said that when the landing gear strut failed, the leading edge of the right wing collided with a large rock. About two feet of the leading edge of the wing was crushed aft about 4 inches.

The closest official weather observation station is Anaktuvuk Pass. On August 6, 2001, at 1355, an automated weather observation system (AWOS) was reporting in part: Wind, 180 degrees (true) at 5 knots; visibility, 10 statute miles; clouds and sky condition, 3,400 feet scattered, 4,600 feet overcast; temperature, 45 degrees F; dew point, 43 degrees F; altimeter, 29.84 inHg.

Aircraft

Registration
N4167Z
Reported as
Piper PA-18
Category
Airplane
Serial number
18-8349
Airframe hours
4,520
Engine
Lycoming O-320-B2A, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Business · Part 91
Registered owner
Arctic North Guiding Inc.
Airworthiness certificate
Standard, Normal
Last inspection
Annual · June 29, 2001 · 25 hours before
Departed
PAKP · Anaktuvuk Pass, AK
Destination
Anaktuvuk Pass, AK

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
55
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land, Single-engine sea
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Last flight review
September 30, 2000
Seat
Front
Flight hours
4,680 total · 4,110 in this make and model · 4,668 as pilot in command · 22 in the last 90 days · 22 in the last 30 days · 4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
154° at 5 knots
Visibility
10 statute miles
Lowest ceiling
4,600 ft overcast
Temperature
45 °F, dew point 43 °F
Altimeter
29.84 inHg
Observed at
PAKP, 35 nm away

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 N4167Z · 1

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