# NTSB ANC93GA020: Piper PA-18-150, N9124D, Beaver, AK, November 12, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: November 12, 1992, 12:00 local (16:00 UTC)
- Place: Beaver, AK
- Coordinates: 66.390747, -147.34024 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=66.3907&lon=-147.3402&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report December 9, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5837
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC93GA020
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5837/pdf
- Page: https://openairdocs.org/ntsb/ANC93GA020

## Probable cause

THE PILOT-IN-COMMAND'S FAILURE TO MAINTAIN AIRSPEED WHICH RESULTED IN AN INADVERTENT STALL AT AN ALTITUDE INADEQUATE TO AFFECT A RECOVERY. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WERE: THE OVERWEIGHT AIRPLANE, AND THE SNOW COVERED MOUNTAINOUS TERRAIN.

## Sequence of events

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

- Loss of control - in flight, maneuvering
  - aircraft weight and balance - exceeded, pilot in command (contributing factor)
  - airspeed - not maintained, pilot in command (cause)
  - stall - inadvertent, pilot in command
- In flight collision with terrain/water, maneuvering
  - terrain condition - mountainous/hilly (contributing factor)
  - terrain condition - snow covered (contributing factor)

## Analysis

THE PURPOSE OF FLIGHT WAS TO COUNT MOOSE. THE PILOT HAD REPORTED TO ANOTHER SURVEY PILOT, WHO WAS WORKING IN AN AREA NEARBY AND JUST OVER THE RIDGE, THAT HIS ASSIGNED AREA HAD SOME FOG IN THE UPPER ELEVATIONS, BUT THAT IT WAS WORKABLE. THE PILOT SUBSEQUENTLY ADVISED THAT THE STANDARD SEARCH HAD BEEN COMPLETED, AND THAT HE WAS COMMENCING THE INTENSIVE SEARCH PATTERN. THERE WAS NO FURTHER CONTACT WITH THE FLIGHT. DURING THE INTENSIVE SEARCH, WHICH TAKES 20-30 MIN TO COMPLETE, A SERIES OF SLIGHTLY OVERLAPPING CIRCLES OR OVALS ARE FLOWN AT 200-300 FT AGL, AT 60 TO 70 MPH, WITH ONE NOTCH (15 DEG) OF FLAPS. THE AIRPLANE IMPACTED SNOW COVERED TUNDRA NOSE FIRST AT AN ANGLE OF APPROX 40 DEG. AT THE TIME OF THE ACCIDENT, THE AIRPLANE WAS APPROX 300 LBS OVER MAX CERTIFICATED GROSS WEIGHT.

## Aircraft

- Registration: [N9124D](https://openairdocs.org/aircraft/N9124D), registered now, S/N 18-6503, built 1958 (OpenAirDocs)
- Reported make and model: PIPER PA-18-150
- Registry model: [Piper PA-18A 150](https://openairdocs.org/model/piper-pa-18a-150) (registry code 7101837) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 18-6503
- Airframe hours: 5083
- Engines: AVCO LYCOMING O-320-A3B 150 horsepower reciprocating
- Damage: Destroyed
- Flight: Public aircraft, Public use
- Operator: Joe A. Firmin
- Registered owner: Joe A. Firmin
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, November 1, 1992, 41 hours before
- Departed: FYU, FORT YUKON, AK
- Destination: FAI, FAIRBANKS, AK
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; toxicology performed; flight hours: 7,000 total, 1,400 in this make and model, 7,000 as pilot in command, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 15 statute miles
- Lowest ceiling: 2,700 ft overcast
- Temperature: 10 °F, dew point -0 °F
- Altimeter: 30.00 inHg

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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