# NTSB ANC23LA015: Piper PA-12, N3904M, Anchorage, AK, January 16, 2023

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: January 16, 2023, 14:08 local (23:08 UTC)
- Place: Anchorage, AK
- Coordinates: 61.132206, -149.94506
- Nearby events: https://openairdocs.org/map.md?lat=61.1322&lon=-149.9451&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Alaska Regional Office
- Parties: FAA
- NTSB case key (mKey): 106629
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC23LA015
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/106629/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=106629
- Page: https://openairdocs.org/ntsb/ANC23LA015

## Probable cause

The pilot's selection of an unsuitable landing site, resulting in the main landing gear wheels breaking through the snow, and a subsequent nose over.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Aircraft capability](https://openairdocs.org/ntsb-findings/01061000): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Piper PA-12, 2 cases](https://openairdocs.org/ntsb-findings/01061000/cases.md?model=7101202), [All aircraft, 57 cases](https://openairdocs.org/ntsb-findings/01061000/cases.md)
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-12, 18 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7101202), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Piper PA-12, 40 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=7101202), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md)

## Analysis

The pilot reported that, during landing on a snow-covered frozen lake in a tundra tire-equipped airplane, the main landing gear wheels broke through the hard-packed snow, and the airplane subsequently nosed over, sustaining substantial damage to the wings, lift struts and rudder. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.

## Aircraft

- Registration: [N3904M](https://openairdocs.org/aircraft/N3904M), registered now, S/N 12-2803, built 1947 (OpenAirDocs)
- Reported make and model: PIPER PA-12
- Registry model: [Piper PA-12](https://openairdocs.org/model/piper-pa-12) (registry code 7101202) (OpenAirDocs)
- Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 12-2803
- Year built: 1947
- Airframe hours: 2574.3
- Engines: LYCOMING o-320-D2B 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 21, 2022, 5 hours before
- Departed: PALH, Anchorage, AK
- Destination: Same as departure
- Airport: A11, Campbell Lake, runway 24, 800 × 15 ft, snow
- Equipment: Satellite tracking device, Handheld GPS, ADS-B

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 53; injuries: none; private; airplane ratings: single-engine sea, single-engine land; medical: class 3; last flight review January 22, 2023; seat: center; restraint: 3-point; flight hours: 299 total, 181 in this make and model, 227 as pilot in command, 6 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 9 statute miles
- Temperature: 25 °F
- METAR: METAR PALH 162353Z AUTO 33003KT 10SM FEW120 M04/M06 A2917 RMK AO2 SLP880 T10391056 11033 21050 56007 TSNO=

## Docket (2 files)

The files NTSB released with the investigation on April 6, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=106629. 17.5 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 12 pages, 16.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15042490&FileExtension=pdf&FileName=ANC23LA015%206120%20N3904M_Redacted-Rel.pdf
- Photos (item 2, PDF, 3 pages, 892 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15042975&FileExtension=pdf&FileName=Photo%20Array%20ANC23LA015-Rel.pdf

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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