# NTSB ANC91LA152: Piper PA-18-150, N2515A, Anaktuvuk Pass, AK, September 12, 1991

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: September 12, 1991, 11:00 local (19:00 UTC)
- Place: Anaktuvuk Pass, AK
- Coordinates: 68.150321, -151.710815 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=68.1503&lon=-151.7108&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed, report March 10, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5625
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC91LA152
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5625/pdf
- Page: https://openairdocs.org/ntsb/ANC91LA152

## Probable cause

THAT THE PILOT INADVERTENTLY STALL/SPUN THE AIRPLANE TO THE GROUND. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S FAILURE TO ADEQUATELY REMOVE THE ICE/FROST FROM THE WINGS BEFORE STARTING THE TAKEOFF.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - in flight, takeoff - initial climb
  - stall/spin - inadvertent, pilot in command (cause)
  - ice/frost removal from aircraft - not performed, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PILOT AND WITNESSES REPORTED THAT JUST AFTER THE AIRPLANE TOOK OFF FROM A REMOTE MOUNTAIN STRIP, THE LEFT WING SUDDENLY DROPPED, AND THE AIRPLANE SPUN TO THE GROUND.  THE PILOT THOUGHT THAT HE HAD POSSIBLY NOT REMOVED ALL OF THE FROST FROM THE WINGS AFTER HE REMOVED THE WING COVERS. THE AIRPLANE HAD BEEN OUTSIDE OVERNIGHT.  THE TEMPERATURES HAD BEEN BELOW FREEZING, AND 2-3 INCHES OF DRY SNOW HAD FALLEN.

## Aircraft

- Registration: [N2515A](https://openairdocs.org/aircraft/N2515A), registered now, S/N 18-1972, built 1952 (OpenAirDocs)
- Reported make and model: PIPER PA-18-150
- Registry model: [Piper PA-18](https://openairdocs.org/model/piper-pa-18) (registry code 7101802) (OpenAirDocs)
- Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 18-1972
- Airframe hours: 4375
- Engines: LYCOMING O-320 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Holt, Robert N.
- Registered owner: Holt, Robert N.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 25, 1991, 40 hours before
- Departed: AKP, ANAKTUVUK PSS, AK
- Destination: AKP, ANAKTUVUK PASS, AK
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: front; flight hours: 1,594 total, 1,532 in this make and model, 90 in the last 90 days, 35 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 360° at 5 knots
- Visibility: 5 statute miles
- Lowest ceiling: 2,000 ft broken

## 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 19910912042829A](https://openairdocs.org/incident/19910912042829A), Sep 12, 1991: Piper PA18, Anatuvuk Pass, AK, Substantial damage. Wing stalled on initial climbout from remote strip. Crash landed. Pilot believes snow and ice not removed from wing

## Other investigations on N2515A (3)

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 ANC90LA073](https://openairdocs.org/ntsb/ANC90LA073), May 21, 1990: Piper PA-18 (N2515A), Talkeetna, AK, substantial damage. Probable cause: COLLAPSE OF THE LEFT MAIN LANDING GEAR DUE TO AN OVERLOAD FAILURE INDUCED BY PREVIOUS DAMAGE WHICH OCCURRED DURING AN IMPROPER LEVEL-OFF BY THE PILOT.
- [NTSB DEN80FTE65](https://openairdocs.org/ntsb/DEN80FTE65), Jul 22, 1980: Piper PA-18 (N2515A), Aurora, CO, substantial damage
- [NTSB MKC79DTG14](https://openairdocs.org/ntsb/MKC79DTG14), Aug 22, 1979: Piper PA-18 (N2515A), Leeds, ND, 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.