Cessna 401 incident near Bethel, Alaska, March 6, 1983
On March 6, 1983, a Cessna 401, registered N7864F, suffered minor damage in an incident near Bethel, Alaska (Bethel airport). It was a business flight under general aviation rules (Part 91). No one was hurt; 6 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this incident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 6, 1983
- Place
- Bethel, Alaska · Bethel · map
- Type
- Incident
- Injuries
- No one was hurt; 6 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 401 · all 401s on the register
- Registration
- N7864F · registry record · serial 401-0207
- Damage
- Minor damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE ACFT RIGHT ENGINE STARTED EMITTING SPARKS FROM THE COWLING DURING NORMAL CRUISE. THE PILOT NOTED A DROP IN MANIFOLD PRESSURE SO HE REDUCED POWER ON THAT ENGINE AND THE SPARKS STOPPED. THE ACFT WAS LANDED AT BETHEL. THE FIRE DEPT. USED A FIRE EXTINGUISHING AGENT ON THE ENGINE. THE DAMAGE WAS MINOR. INSPECTION OF THE RIGHT ENGINE REVEALED A BROKEN BOLT ONTHE EXHAUST CLAMP WHICH SECURED THE EXHAUST PIPE TO THE TURBOCHARGER. THE CLAMP WHICH SECURED THE PIPE TO THE ENGINE NACELLE HAD SLIPPED OFF THE BRACKET. THIS ALLOWED THE PIPE TO SLIP DOWN AND RELEASE HOT EXHAUST GASES INTO THE ENGINE NACELLE. THIS HEATED THE ENGINE EXCESSIVELY AND REMOVED THE WASTE GATE FROM THE OPERATIONAL SYSTEM OF THE ENGINE. THE BROKEN BOLT IS A PART OF THE CLAMP P/N MVT 68637-375M.
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: 1,454 hours in all; 150 in this make and model; 79 in the last 90 days; 1,197 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Last inspection: annual inspection, March 1, 1982
- Maximum gross weight: 6,300 lb
- Seats: 8
- Landing gear: retractable
- Engine: Continental TSIO-520 (piston); 0 hours total
The flight
- Departed from: BET Bethel
- Destination: FAI Fairbanks
- Flight plan: IFR
- Runway 0
Weather at the time
- Light: night, dark
- Wind: from 070° at 9 knots
- Visibility: 7 statute miles
- Sky: overcast at 1,700 ft; not recorded
- Temperature: 28°F (-2°C), dew point 27°F (-3°C)
- Altimeter: 29.00 inHg
- Observation at 5:54 am from BET
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 5 |
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.