# NTSB ANC91LA123: Piper PA-18-150, N180AT, Gulkana, AK, August 10, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 10, 1991, 08:45 local (16:45 UTC)
- Place: Gulkana, AK
- Coordinates: 55.919231, -159.489028 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=55.9192&lon=-159.4890&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 10, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5600
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC91LA123
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5600/pdf
- Page: https://openairdocs.org/ntsb/ANC91LA123

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN ADEQUATE AIRSPEED, RESULTING IN A STALL, HARD LANDING AND COLLAPSE OF THE MAIN LANDING GEAR.

## Sequence of events

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

- Hard landing, landing - flare/touchdown
  - airspeed(vs) - not maintained, pilot in command (cause)
- Main gear collapsed, landing - flare/touchdown
  - landing gear,main gear - overload

## Analysis

THE PILOT STATED THAT HE ALLOWED THE APPROACH TO THE MOUNTAINTOP TO GET TOO LOW AND SLOW.  JUST PRIOR TO TOUCHDOWN, ONE WING STALLED, CAUSING THE AIRPLANE TO LAND HARD.  ONE MAIN LANDING GEAR COLLAPSED AND ONE WING HIT THE GROUND.

## Aircraft

- Registration: [N180AT](https://openairdocs.org/aircraft/N180AT), registered now, S/N 18-7809096, built 1978 (OpenAirDocs)
- Reported make and model: PIPER PA-18-150
- 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: 18-7809096
- Airframe hours: 967
- Engines: LYCOMING O-320-A2B 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: John W. Clark
- Registered owner: Shawn W. Clark
- Airworthiness certificate: Standard, Normal; Standard, Utility
- Last inspection: Annual, November 6, 1990, 967 hours before
- Departed: GULKANA, AK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 1,000 total, 550 in this make and model, 900 as pilot in command, 50 in the last 90 days, 20 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 5 knots
- Visibility: 40 statute miles
- Lowest ceiling: none

## 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 19910810033719A](https://openairdocs.org/incident/19910810033719A), Aug 10, 1991: Piper PA18150, Gulkana, AK, Substantial damage. Too slow on flare. Wing stalled,impacted mountain top strip collapsing right gear. Strip only 500 feet in length.

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.

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