Maule M-6-235 accident near Tyonek, Alaska, February 13, 2021
On February 13, 2021 at about 10:00 pm local time, a 1983 Maule M-6-235, registered N56517, was substantially damaged in an accident during landing near Tyonek, Alaska. It was a personal flight under general aviation rules (Part 91). 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s selection of unsuitable terrain for landing, which resulted in the airplane encountering deep snow and coming to rest inverted.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 13, 2021 · about 10:00 pm local time
- Place
- Tyonek, Alaska · map
- Type
- Accident
- Injuries
- 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Maule M-6-235, built 1983 · all M-6-235s on the register
- Registration
- N56517 · registry record · serial 7450C
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Nose over/nose down during landing
- Loss of control on ground during landing defining event
- Miscellaneous/other during landing
The NTSB's findings
- 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
Pilot
- Certificate: private
- Ratings: single-engine land; single-engine sea
- Flight time: 1,998 hours in all; 10 in the last 90 days; 6 in the last 30 days; 1,998 as pilot in command
- Last flight review: September 28, 2020
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 2,363.9 hours
- Last inspection: annual inspection, June 28, 2020
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-540-W1A5 (piston); 1,150 hours total
The flight
- Departed from: BCV Birchwood AK at 8:30 pm
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 030° at 5 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 11,000 ft
- Temperature: 16°F (-9°C), dew point 7°F (-14°C)
- Altimeter: 29.83 inHg
- Observation at 12:53 pm from PANC, 58 miles away
Weather report (METAR): PANC 132153Z 03005KT 10SM FEW110 M09/M14 A2983 RMK AO2 SLP106 T10941139
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number ANC21LA017.