# NTSB ANC99LA031: Piper PA-12, N4040M, Big Lake, AK, March 7, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 7, 1999, 15:40 local (19:40 UTC) - Place: Big Lake, AK - Coordinates: 61.459629, -150.090118 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.4596&lon=-150.0901&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report April 25, 2001 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 45888 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC99LA031 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/45888/pdf - Page: https://openairdocs.org/ntsb/ANC99LA031 ## Probable cause The pilot's selection of unsuitable terrain for landing the wheel equipped airplane. A factor associated with the accident was the soft snow covering the frozen lake. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - On ground/water encounter with terrain/water, landing - roll - terrain condition - snow covered (contributing factor) - terrain condition - water,frozen - terrain condition - soft (contributing factor) - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause) - Nose over, landing - roll ## Analysis The pilot of the wheel equipped airplane said he saw other airplanes landing on the surface of the frozen lake. He decided to land in the same area. The pilot said that during the landing roll the snow was initially hard packed as it had appeared from the air. The wheels then contacted soft snow, and the airplane nosed over. ## Factual narrative On March 7, 1999, about 1540 Alaska standard time, a wheel equipped, Piper PA-12, N4040M, sustained substantial damage while landing on the frozen surface of Flathorn Lake, approximately 20 miles southwest of Big Lake, Alaska. The airline transport pilot and the two passengers on board were not injured. The airplane was being operated as a local, personal flight under 14 CFR Part 91. The flight departed Anderson Lake, Palmer, Alaska, about 1500. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The pilot told the NTSB investigator-in-charge (IIC) during a telephone interview on March 8, and wrote in his NTSB Pilot / Operator report, that he saw other airplanes landing on the frozen surface of Flathorn Lake, and decided to land as well. During landing the snow was initially hard packed as it had appeared from the air. During the landing roll, the airplane's tires sank into soft snow, and the airplane nosed over. ## Aircraft - Registration: [N4040M](https://openairdocs.org/deregistered/N4040M-2020-01-31), registration cancelled 2020-01-31, S/N 12-2923, 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: 12-2923 - Airframe hours: 2040 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Mark Alger - Registered owner: Randall J. Lufberry - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 7, 1998, 20 hours before - Departed: PALMER, AK - Destination: PALMER, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 38; commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: front; flight hours: 12,000 total, 40 in this make and model, 5,000 as pilot in command, 130 in the last 90 days, 40 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 25,000 ft overcast - Temperature: 21 °F, dew point 5 °F - Altimeter: 29.00 inHg - Observed at: ANC, 26 nm away ## 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 19990307014119A](https://openairdocs.org/incident/19990307014119A), Mar 7, 1999: Piper PA12, Big Lake, AK, Substantial damage. (.19) On March 7, 1999, about 1540 Alaska standard time, a wheel equipped, Piper PA-12, N4040M, sustained substantial damage while landing on the frozen… ## Other investigations on N4040M (2) 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 CEN18LA039](https://openairdocs.org/ntsb/CEN18LA039), Nov 22, 2017: Piper PA 12 (N4040M), Dickinson, ND, substantial damage. Probable cause: The pilot’s failure to attain adequate airspeed during the short field takeoff, which resulted in an exceedance of the airplane’s critical angle of attack and an aerodynamic stall. - [NTSB ANC77DAH41](https://openairdocs.org/ntsb/ANC77DAH41), Sep 16, 1977: Piper PA-12 (N4040M), Anchorage, AK, 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.