Beech K35 accident near Grass Valley, California, October 11, 1991
On October 11, 1991 at about 11:00 pm local time, a Beech K35, registered N9559R, was substantially damaged in an accident near Grass Valley, California (Nevada County airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE INADVERTENT ENCOUNTER WITH A MICROBURST/DOWNBURST PHENOMENA ASSOCIATED WITH THUNDERSTORM ACTIVITY. A FACTOR IN THE ACCIDENT WAS THE FAILURE OF THE PILOT TO ADEQUATELY ASSESS THE WEATHER CONDITIONS DURING THE LANDING ATTEMPT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 11, 1991 · about 11:00 pm local time
- Place
- Grass Valley, California · Nevada County · map
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech K35 · all K35s on the register
- Registration
- N9559R · no longer on the register · serial D6125
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
IN AN ORAL STATEMENT, THE PILOT SAID THAT AS HE APPROACHED THE AIRPORT HE OBSERVED SQUALL LINE ACTIVITY AND DECIDED TO ORBIT UNTIL THE WEATHER CLEARED. AFTER THE WEATHER CONDITIONS VISUALLY IMPROVED, THE PILOT ENTERED THE PATTERN FOR LANDING. HE STATED THAT ON SHORT FINAL APPROACH THE AIRCRAFT ENCOUNTERED SEVERE TURBULENCE AND A DOWN DRAFT. THE PILOT INITIATED A GO AROUND, HOWEVER, THE AIRCRAFT ROLLED VIOLENTLY AND THE WING TIP STRUCK THE GROUND. AN AIRPORT ATTENDANT STATED THAT HE WAS IN THE OFFICE WHERE THE WEATHER OBSERVATION INSTRUMENTS ARE LOCATED AT THE TIME OF THE ACCIDENT. HE SAID THAT THE WINDS WERE 30 TO 40 KNOTS WITH SUDDEN 180 DEGREE CHANGES IN DIRECTION AT THE TIME THE PILOT ATTEMPTED HIS APPROACH. THUNDERSTORM CLOUDS WERE VISIBLE IN THE DISTANCE AND THE AIRPORT WAS EXPERIENCING INTERMITTENT HEAVY RAIN SHOWERS.
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: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 316 hours in all; 57 in this make and model; 25 in the last 90 days; 13 in the last 30 days; 228 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 2,380 hours
- Last inspection: annual inspection, November 3, 1990; 57 hours since
- Maximum gross weight: 2,949 lb
- Seats: 4
- Landing gear: retractable
- Engine: Continental IO-470C (piston); 0 hours total
The flight
- Departed from: RHV San Jose CA at 10:00 pm
- Flight plan: none
- Runway 7, 3,920 ft by 50 ft
Weather at the time
- Light: daylight
- Wind: at 15 knots, gusting 40
- Visibility: 50 statute miles
- Sky: overcast at 4,000 ft; clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 2 |
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.