Amateur-built B-8-M accident near Deer Park, Washington, September 23, 1986
On September 23, 1986 at about 8:00 pm local time, a amateur-built B-8-M (gyroplane), registered N4621N, was destroyed in an accident near Deer Park, Washington (Deer Park airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed. 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
- September 23, 1986 · about 8:00 pm local time
- Place
- Deer Park, Washington · Deer Park · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built B-8-M
- Registration
- N4621N · no longer on the register · serial 43146739
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE GYROCOPTER WAS OBSERVED OSCILLATING IN FLIGHT PRIOR TO DESCENDING TO GROUND IMPACT. INVESTIGATION REVEALED INFLIGHT CONTACT BETWEEN THE MAIN ROTOR AND VERTICAL FIN/PUSHER PROPELLER HAD TAKEN PLACE. NO MECHANICAL FAILURE WAS FOUND WHICH WOULD HAVE RESULTED IN THE CONTACT.
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
- Flight time: 69 hours in all; 46 in this make and model; 6 in the last 90 days; 3 in the last 30 days; 50 as pilot in command
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: frt
The aircraft
- Last inspection: annual inspection, October 5, 1985
- Maximum gross weight: 600 lb
- Seats: 1
- Landing gear: fixed
- Engine: Mcculloch 4318A (piston); 0 hours total
The flight
- Departed from: 07S Deer Park WA at 7:30 pm
- Flight plan: none
- Runway 16, 6,100 ft by 75 ft
Weather at the time
- Light: daylight
- Wind: from 190° at 14 knots
- Visibility: 20 statute miles
- Sky: broken clouds at 12,000 ft; not recorded at 12,000 ft
- Temperature: 63°F (17°C), dew point 36°F (2°C)
- Altimeter: 29.00 inHg
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.