Piper PA-31-350 incident near Fairbanks, Alaska, October 2, 1991
On October 2, 1991 at about 9:20 pm local time, a Piper PA-31-350, registered N200AK, suffered minor damage in an incident near Fairbanks, Alaska. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 5 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
INCORRECT INSTALLATION OF CRANKSHAFT COUNTERWWEIGHT ROLLERS BY THE MANUFACTURER DURING REMANUFACTURE OF THE ENGINE. FACTOR WAS THE INADEQUATE SURVEILLANCE OF THE ENGINE ASSEMBLY PROCESS BY THE MANUFACTURER.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 2, 1991 · about 9:20 pm local time
- Place
- Fairbanks, Alaska · map
- Type
- Incident
- Injuries
- No one was hurt; 5 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-31-350 · all PA-31-350s on the register
- Registration
- N200AK · no longer on the register · serial 31-8052180
- Damage
- Minor damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
DURING CRUISE FLIGHT, THE LEFT ENGINE LOST POWER AND OIL PRESSURE. AN ENGINE TEARDOWN ANALYSIS SHOWED THAT THE CRANKSHAFT COUNTERWEIGHTS HAD TWO INCORRECT OF THE FOUR INSTALLED ROLLERS. ALL FOUR ROLLERS WERE PART NO. 73648. ACCORDING TO TEXTRON LYCOMING, THE CORRECT ROLLER CONFIGURATION SHOULD HAVE BEEN 'TWO PART NO. 73648 5.1 ORDER AND TWO PART NO. 76788 6.3 ORDER ROLLERS.' AS CONFIGURED, THE ENGINE WOULD EXPERIENCE UNACCEPTABLE 6TH ORDER TORSIONAL VIBRATIONS.
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: airline transport pilot, private
- Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane
- Flight time: 8,000 hours in all; 6,000 in this make and model; 300 in the last 90 days; 100 in the last 30 days; 7,800 as pilot in command; 100 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,763 hours
- Last inspection: approved inspection programme, September 27, 1991; 26 hours since
- Maximum gross weight: 7,000 lb
- Seats: 10
- Landing gear: retractable
- Engine: Lycoming TIO-540J2BD (piston); 0 hours total
- Operator: Frontier Flying Service INC.
The flight
- Departed from: FAI Fairbanks AK at 4:15 pm
- Destination: CXF Coldfoot AK
- Flight plan: VFR
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 99 statute miles
- Sky: clear
- Temperature: 39°F (4°C), dew point 0°F (-18°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 4 |
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.
Other NTSB records under N200AK the same tail number, which may have belonged to a different aircraft at the time
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.