Amateur-built BENSEN B-8M accident near Lower Lake, California, April 13, 1985
On April 13, 1985 at about 10:47 pm local time, a amateur-built BENSEN B-8M (gyroplane), registered N4544L, was substantially damaged in an accident near Lower Lake, California (Pearce Fld airport). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured. 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
- April 13, 1985 · about 10:47 pm local time
- Place
- Lower Lake, California · Pearce Fld · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built BENSEN B-8M BENSEN B-8
- Registration
- N4544L · no longer on the register · serial 1
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
FOLLOWING A NORMAL TAKEOFF WITH THE FUEL TANK ONE-HALF FULL, THE ACFT CLIMBED TO 1000 FT AGL AT WHICH TIME ENGINE PWR WAS GRADUALLY LOST. A GRND WITNESS REPORTED HEARING THE ENG SPUTTER OR MISS. THE PLT ATTEMPTED TO RETURN TO THE ARPT BUT HAD INSUFFICIENT ALTITUDE AND THE ACFT COLLIDED WITH A 50 TO 60 FT TALL TREE. THE REASON FOR THE LOSS OF ENG PWR IS UNKNOWN. THE PLT WAS THE BUILDER OF THE EXPERIMENTAL ACFT & HAD JUST REINSTALLED THE ENG PRIOR TO THE ACCIDENT.
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: gyroplane
- Flight time: 82 hours in all; 82 in this make and model; 70 as pilot in command
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 75 hours
- Last inspection: annual inspection, September 26, 1984; 0 hours since
- Maximum gross weight: 600 lb
- Seats: 1
- Landing gear: fixed
- Engine: Mcculloch 100-13 (piston); 0 hours total
The flight
- Departed from: 209 Lower Lake CA at 10:40 pm
- Flight plan: none
- Runway 30, 2,485 ft by 50 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 75°F (24°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.