Enstrom F-28C accident near Marmath, North Dakota, May 17, 1982
On May 17, 1982, a Enstrom F-28C (helicopter), registered N8617J, was substantially damaged in an accident near Marmath, North Dakota. It was an instructional flight under general aviation rules (Part 91). No one was hurt; 1 person was 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 accident. 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
- May 17, 1982
- Place
- Marmath, North Dakota
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Enstrom F-28C · all F-28Cs on the register
- Registration
- N8617J · no longer on the register · serial 516-2
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT REPORTED THAT WHILE HE WAS IN FLIGHT AT ABOUT 75 TO 80 FT AGL, THE ENGINE LOST POWER. DURING AN AUTOROTATIVE LANDING IN AN OPEN PASTURE, A SKID DUG INTO THE GROUND AND THE HELICOPTER ROLLED OVER. A SUBSEQUENT ENGINE TEARDOWN REVEALED EVIDENCE THAT THE ENGINE HAD BEEN OPERATED IN AN OVERSPEED CONDITION OVER A PROLONGED PERIOD OF TIME. THERE WAS EVIDENCE OF HIGH VALVE SEATING VELOCITIES AND BOUNCING, THE UPPER SPRING SEATS HAD BEEN STRIKING THE TOPS OF THE VALVE GUIDES, FATIGUE FAILURE OF THE KEEPERS HAD OCCURRED, AND SUBSEQUENTLY, A VALVE FAILED FROM FATIGUE.
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: student
- Ratings: rotorcraft: helicopter
- Flight time: 51 in this make and model
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: unk
The aircraft
- Airframe total time: 483 hours
- Last inspection: inspection type not recorded; 60 hours since
- Maximum gross weight: 2,350 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming HIO-360-E1BD (piston); 0 hours total
The flight
- Departed from: 3U6 Baker MT at 3:30 pm
- Destination: Ellis WI
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 25 statute miles
- Sky: not recorded; clear
- Temperature: 135°F (57°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.