# NTSB ANC92LA049: Piper PA-18, N83367, Shageluk, AK, March 21, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 21, 1992, 12:00 local (16:00 UTC)
- Place: Shageluk, AK
- Coordinates: 62.639495, -159.530258 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=62.6395&lon=-159.5303&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 26, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5701
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC92LA049
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5701/pdf
- Page: https://openairdocs.org/ntsb/ANC92LA049

## Probable cause

THE LEFT MAIN LANDING GEAR SKI BEING PARTIALLY DISCONNECTED AT THE TIME OF THE LANDING.  CONTRIBUTING FACTORS WERE THE INADEQUATE PREFLIGHT BY THE PILOT, AND THE SNOW COVERED LANDING AREA.

## Sequence of events

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

- Airframe/component/system failure/malfunction, landing - flare/touchdown
  - landing gear,ski assembly - disconnected (cause)
  - aircraft preflight - inadequate, pilot in command (contributing factor)
- Nose over, landing - flare/touchdown
  - terrain condition - snow covered (contributing factor)

## Analysis

AS THE SKI EQUIPPED AIRPLANE TOUCHED DOWN ON THE SNOW COVERED FROZEN RIVER, THE LEFT MAIN LANDING GEAR BROKE AT THE AXLE, AND THE AIRPLANE NOSED OVER.  INVESTIGATION REVEALED THAT THE LEFT SKI RETAINING NUT AND ITS COTTER PIN WERE MISSING.  THIS ALLOWED THE SKI TO PARTIALLY SLIDE OFF THE AXLE IN FLIGHT.  THE PILOT STATED THAT THIS WAS THE SECOND TIME THAT THE AIRPLANE HAD BEEN SABOTAGED OR VANDALIZED.

## Aircraft

- Registration: [N83367](https://openairdocs.org/aircraft/N83367), registered now, S/N 18-7609100, built 1976 (OpenAirDocs)
- Reported make and model: PIPER PA-18
- 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: 18-7609100
- Airframe hours: 1200
- Engines: LYCOMING O-320-A2B 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Deacon, Nelson H.
- Registered owner: Deacon, Henry
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, January 2, 2000
- Departed: KGX, GRAYLING, AK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; private; airplane ratings: single-engine land; medical: class 3, expired; seat: front; flight hours: 600 total, 550 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 120° at 5 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 3 °F

## 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 19920321009109A](https://openairdocs.org/incident/19920321009109A), Mar 21, 1992: Piper PA18150, Shageluk, AK, Substantial damage. Left main ski equipped gear collapsed on landing. Axle nut came off due no cotter pin. Ski slid partially off axle.

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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