Bell 206B accident near Aniak, Alaska, July 10, 2003
On July 10, 2003 at about 2:00 am local time, a Bell 206B (helicopter), registered N111MT, was substantially damaged in an accident near Aniak, Alaska. It was a positioning flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The compressor discharge pressure line (Pc line) B-nut coming loose at the fuel control unit, which resulted in a total loss of engine power, and subsequent in-flight collision with trees during an autorotation. A factor associated with the accident was the improper installation of the Pc line B-nut by company maintenance personnel.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 10, 2003 · about 2:00 am local time
- Place
- Aniak, Alaska · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206B · all 206Bs on the register
- Registration
- N111MT · registry record · serial 1989
- Damage
- Substantial damage
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The helicopter was operating as a Title 14, CFR Part 91, positioning flight in visual meteorological conditions when it had a total loss of engine power while in cruise flight. The pilot said the first indication of a problem was the illumination of the auto-relight indicator, followed by the engine fail light. He initiated an autorotation towards a clearing, but was unable to reach it. The helicopter impacted trees about 30 feet above the ground. During the inspection of the engine, the compressor discharge pressure line (Pc line) was removed at the compressor scroll, and compressed air was applied. Technicians reported air escaping at the Pc line's junction with the fuel control unit. The B-nut on the Pc line was loose at the fuel control unit. There was evidence of fretting on the B-nut fitting, and there were smears of orange torque seal material on the B-nut. No torque seal material was present on the B-nut fitting. The engine logbook indicated the fuel control unit was replaced by company mechanics 178 hours prior to the accident.
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
Pilot
- Certificate: commercial pilot
- Ratings: instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,786 hours in all; 84 in the last 90 days; 72 in the last 30 days; 1,720 as pilot in command
- Last flight review: June 13, 2003
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
- Injury: minor injuries
The aircraft
- Airframe total time: 7,701 hours
- Last inspection: 100-hour inspection, June 3, 2003; 26 hours since
- Maximum gross weight: 3,200 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: RDV Red Devil AK at 8:30 pm
- Destination: PANI Aniak AK
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: broken clouds at 1,500 ft; clear
- Temperature: 75°F (24°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.
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.