Cessna 207 incident near Quinhagak, Alaska, May 18, 2001
On May 18, 2001 at about 5:00 am local time, a Cessna 207, registered N917AC, suffered minor damage in an incident near Quinhagak, Alaska. It was a positioning flight under general aviation rules (Part 91). 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
An in-flight fracture of the engine crankshaft during descent, precipitated by restricted oil flow through an internal engine oil passage/port.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 18, 2001 · about 5:00 am local time
- Place
- Quinhagak, Alaska · map
- Type
- Incident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 207 · all 207s on the register
- Registration
- N917AC · registry record · serial 20700517
- Damage
- Minor damage
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The certificated commercial pilot reported that during a flight earlier on the day of the incident, he had difficulty controlling the propeller rpm, so he elected to make a precautionary landing. The pilot related that after a mechanic replaced the propeller governor, the airplane's engine and governor appeared to be operating normally, so they began their flight back to the operator's base. He said that about 10 minutes after departure, while in cruise, level flight, he noted a light sheen of oil forming on the windshield, and he elected to make a precautionary landing on a remote beach. As he retarded the throttle to start the descent, the propeller rpm increased for about 20 seconds, followed by the propeller detaching from the engine. He said that he was able to glide the airplane to the beach, and land without further incident. The airplane was equipped with a Teledyne Continental Motors (TCM) IO-520-F engine. The propeller and engine crankshaft flange were eventually recovered, and sent to the NTSB metallurgical laboratory for examination. A Safety Board metallurgist examined the fractured crankshaft flange, and reported that his initial visual examination revealed a fatigue fracture, originating from a heat check site. A postincident investigation revealed that the engine crankshaft had been replaced by TCM, 94.3 hours before the crankshaft separation. An engine log book notation, entered by TCM, indicated that the reason for removal was: "...for compliance with CSB 99-3A." According to a representative from TCM's in-house analytical laboratory the crankshaft was a remanufactured part that reportedly was ground undersize, and re-nitrided at TCM. In the presence of an NTSB Investigator, the engine was disassembled. The investigator noted a significant amount of heat discoloration, with modest circumferential scoring of two forward most bearings, just aft of the fractured propeller shaft, indicating a localized loss of lubrication. He added that the oil transfer collar assembly was fractured in one location.
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: multi-engine land; single-engine land; instrument: airplane
- Flight time: 3,313 hours in all; 1,677 in this make and model; 110 in the last 90 days; 61 in the last 30 days; 3,225 as pilot in command
- Last flight review: February 20, 2001
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 6,615 hours
- Last inspection: 100-hour inspection, April 2, 2001; 45 hours since
- Maximum gross weight: 3,800 lb
- Seats: 6
- Landing gear: fixed
- Engine: Continental IO-520F27-B (piston); 0 hours total
The flight
- Departed from: PTU Platinum AK at 11:45 pm
- Destination: BET Bethel AK
Weather at the time
- Light: daylight
- Wind: at 10 knots
- Visibility: 50 statute miles
- Sky: scat at 6,000 ft
- Temperature: 54°F (12°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.
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.