Amateur-built LM-1 accident near Sierraville, California, July 30, 1990
On July 30, 1990 at about 8:45 pm local time, a amateur-built LM-1 (glider), registered N9646Z, was destroyed in an accident near Sierraville, California. It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
PILOT'S FAILURE TO SEE AND AVOID A TREE DURING HIS LANDING APPROACH.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 30, 1990 · about 8:45 pm local time
- Place
- Sierraville, California · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built LM-1
- Registration
- N9646Z · no longer on the register · serial LM-1
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT OF A GLIDER WAS UNABLE TO FIND ANY LIFT GENERATION AND ELECTED TO LAND IN A MEADOW. DURING THE APPROACH HIS RIGHT WING COLLIDED WITH A TREE AND PITCHED DOWN. THE GLIDER COLLIDED WITH THE GROUND AND WAS DESTROYED. THE PILOT REPORTED NO FLIGHT CONTROL PROBLEMS 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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instructor: glider; rotorcraft: glider
- Flight time: 3,200 hours in all; 400 in this make and model; 10 in the last 90 days; 10 in the last 30 days; 2,600 as pilot in command; 600 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 400 hours
- Last inspection: annual inspection; 10 hours since
- Maximum gross weight: 630 lb
- Seats: 1
- Landing gear: fixed
- Engine: (type not recorded); 0 hours total
The flight
- Departed from: TRK Truckee CA at 8:30 pm
- Destination: TRK
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 270° at 5 knots, gusting 10
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 0°F (-18°C)
- Observation at 1:45 pm
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.