Dehavilland DHC-3 accident near Bettles, Alaska, August 21, 2021
On August 21, 2021 at about 9:25 pm local time, a 1956 Dehavilland DHC-3, registered N560TR, was substantially damaged in an accident during enroute near Bettles, Alaska. It was a business flight under charter and air-taxi rules (Part 135). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The seizure of the engine during flight for undetermined reasons, which led to a total loss of engine power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 21, 2021 · about 9:25 pm local time
- Place
- Bettles, Alaska · map
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Dehavilland DHC-3, built 1956 · all DHC-3s on the register
- Registration
- N560TR · registry record · serial 141
- Damage
- Substantial damage
- Flight
- Business flight · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, while on the base leg approach, he heard a “loud bang,” and the engine lost total power. The pilot determined that the airplane would not be able to reach its intended destination, so he turned the airplane into the wind and made a forced landing on tundra-covered terrain, which resulted in substantial damage to the fuselage. The airplane’s maintenance records were unremarkable. Postaccident examination of the engine revealed that it had seized and sheared the propeller spline into two pieces. The accessory wall could not be removed because of the extensive internal damage to the engine. As a result, the investigation was unable to determine the reason that the engine seized during the flight.
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
- Powerplant sys/comp malf/fail during enroute defining event
The NTSB's findings
- Not determined › Not determined › (general) › (general) › Unknown/Not determined
- Aircraft › Aircraft power plant › Engine (reciprocating) › (general) › Unknown/Not determined
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 17,000 hours in all; 600 in this make and model; 300 in the last 90 days; 150 in the last 30 days; 16,500 as pilot in command
- Last flight review: June 18, 2021
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 16,402.4 hours
- Last inspection: annual inspection, June 13, 2021
- Maximum gross weight: 9,000 lb
- Seats: 11
- Landing gear: fixed
- Engine: Pezetel ASZ-621R-M18 (piston); 1,890 hours total
- Operator: Sourdough Air Service, Inc.
The flight
- Departed from: Issygok Lake AK at 8:00 pm
- Destination: Jobe Lake AK
Weather at the time
- Light: daylight
- Wind: from 240° at 10 knots, gusting 17
- Visibility: 10 statute miles
- Sky: broken clouds at 4,600 ft
- Temperature: 48°F (9°C), dew point 37°F (3°C)
- Altimeter: 29.93 inHg
- Observation at 12:56 pm from PAKP, 91 miles away
Weather report (METAR): PAKP 212056Z AUTO 24010G17KT 10SM BKN046 09/03 A2993 RMK AO2 SLP162 60000 T00940033 56010
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on September 27, 2023. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120 | PDF, 9 pages | View Download |
| 2 | FAA Inspector's Statement | PDF, 1 page | View Download |
| 3 | Photos | PDF, 3 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.