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Atlas / NTSB / ANC21LA017

NTSB CAROL · Event

Event ANC21LA017

2021-02-13 Tyonek, Alaska, United States Minor 1 aircraft Status: Completed

Registry · N56517

FAA Aircraft Registry record.

Make / Model

MAULE M-6-235

Year of manufacture

1983 · 38 years old at event

Engine

LYCOMING IO-540 SER (300 hp)

Seats / Engines

4 seats · 1 engine

Last airworthiness date

19830702

ADS-B equipped

Yes — Mode-S A73C18

Registrant of record

ANDREWS PAUL

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The pilot’s selection of unsuitable terrain for landing, which resulted in the airplane encountering deep snow and coming to rest inverted.

Factual narrative

The pilot initially reported that before landing on a snow-covered glacier, he intended to fly a low pass over the snow-covered site and briefly touchdown to determine the condition of the snowpack, a maneuver commonly known as dragging the landing site. He said that during a second downhill pass over the site, he inadvertently allowed the tailwheel-ski equipped airplane to slow while attempting to “set the track more fully”. He added that, he mis-judged the snow depth and allowed the airplane to slow too much. Subsequently, the ski tips dug into the snow and the airplane came to rest inverted.   The airplane sustained substantial damage to the fuselage, the wings, and the empennage. The pilot initially reported there were no preimpact mechanical failures or malfunctions with the airframe and engine that would have precluded normal operation. The pilot later reported that he believed the brake calipers had obstructed the movement of the skis. Two witness marks were observed on the skis that indicated the brake calipers had impacted the skis. A Federal Aviation Administration (FAA) aviation safety inspector (airworthiness) examined the airplane and stated that there were no preimpact mechanical failures or malfunctions found with the airplane. Based on the available evidence, it is likely that the damage to the skis from the brake calipers were from impact damage. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).

  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Landing flare-Not attained/maintained
  • Personnel issues-Action/decision-Info processing/decision-Decision making/judgment-Pilot
  • Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot
  • Environmental issues-Physical environment-Runway/land/takeoff/taxi surface-Snow/slush/ice covered surface-Effect on operation
  • Environmental issues-Physical environment-Runway/land/takeoff/taxi surface-Soft surface-Effect on operation

Verbatim from NTSB's published report. Source file NTSB_2021_ANC21LA017.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.