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 November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 21, 2021 · about 9:25 pm local time · cases in 2021
- 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 other cases naming the engine
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 |
Photographs from the investigation 3 pictures from the NTSB's docket, as the NTSB released them
Photo 1 - View of airplane at the scene
Photo 2 – View of damaged right forward fuselage
Photo 3 – View of right rear fuselage damageThe NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.
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 · our copy | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Connections how this case links to the rest of the register
- N560TR on the register today · the tail number may have moved to another aircraft since
- Dehavilland DHC-3 67 registered today · the model family and its accident history
- Dehavilland 861 aircraft on the register
- Engine: Pezetel ASZ-621R-M18 9 aircraft carry this series today · as the NTSB recorded it
- Accidents and incidents in Alaska 5,932 since 1982 · 825 in the last ten years
- Alaska 9,142 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/ANC21LA094.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.