Cessna 207A accident near Bethel, Alaska, August 8, 2003
On August 8, 2003 at about 8:53 pm local time, a Cessna 207A, registered N6439H, was substantially damaged in an accident near Bethel, Alaska. It was flown under charter and air-taxi rules (Part 135). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A complete loss of engine power during cruise flight due to the shifting of a main crankshaft bearing that produced a fatigue failure of the crankshaft. A factor contributing to the accident was unsuitable terrain for a forced landing, which resulted in a nose over .
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 8, 2003 · about 8:53 pm local time
- Place
- Bethel, Alaska · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 207A · all 207As on the register
- Registration
- N6439H · no longer on the register · serial 20700525
- Damage
- Substantial damage
- Flight
- Flight · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The commercial certificated pilot was conducting a non-scheduled domestic cargo flight carrying mail, and the airplane was in cruise flight about 1,000 feet agl when the engine lost all power. The pilot performed a forced landing in rough, tundra covered terrain. During the landing, the airplane nosed over. The engine was overhauled 1090.9 hours before the accident. During the overhaul process, the engine case was sent to a vendor to be welded and rebored to match original engine case specifications. A postaccident examination of the engine revealed that the number 1 main bearing was deformed in its bearing saddle, and portions of the number 2 main bearing were flattened, fractured and fragmented, and were found in the engine case. The number 2 bearing saddle was extensively distorted and gouged. The engine crankshaft was fractured at the radius of the number 2 main bearing and the number 3 crankshaft cheek, adjacent to the main bearing surface. The fracture surface had discoloration consistent with high heat, and beach marks consistent with fatigue. The area of the number 2 engine bearing saddle, under the bearing insert, had several areas of cracking and exfoliation of the case material along the edges of the oil supply channel. No evidence of engine case fretting was observed during the examination. The engine case was examined by the manufacturer's metallurgical personnel. The report of examination stated that the case contained no signs of lubrication distress on the journals. The manufacturer's metallurgist stated that a determination of a weld repair at the number 2 main bearing support could not be made with a high degree of certainty, although there were several work order stamps on the crankcase indicating that it had been reworked.
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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 2,070 hours in all; 395 in this make and model; 272 in the last 90 days; 130 in the last 30 days; 2,020 as pilot in command; 1,100 on instruments
- Last flight review: March 15, 2003
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 14,408 hours
- Last inspection: approved inspection programme, August 8, 2003; 1 hours since
- Maximum gross weight: 3,800 lb
- Seats: 7
- Landing gear: fixed
- Engine: Continental IO-520F (piston); 0 hours total
- Operator: Hageland Aviation Inc.
The flight
- Departed from: TLT Tuluksak AK at 3:45 pm
- Destination: 4A2 Atmautluak AK
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: a few clouds at 6,000 ft
- Temperature: 70°F (21°C), dew point 59°F (15°C)
- Altimeter: 30.27 inHg
- Observation at 3:53 pm from PABE, 8 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.