Rockwell 690B accident near Herlong, California, December 31, 1992
On December 31, 1992 at about 11:36 pm local time, a Rockwell 690B, registered N300CP, was destroyed in an accident near Herlong, California. It was a flight of an unrecorded kind under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
AN INADVERTENT ENCOUNTER WITH SEVERE TURBULENCE WHICH EXCEEDED THE DESIGN STRENGTH OF THE AIRPLANE'S STRUCTURE.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 31, 1992 · about 11:36 pm local time
- Place
- Herlong, California · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Rockwell 690B
- Registration
- N300CP · registry record · serial 11374
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT AND FLIGHT NURSE WERE EN ROUTE TO PICK UP A MEDICAL PATIENT. THE AIRPLANE EXPERIENCED AN IN-FLIGHT BREAKUP WHILE FLYING BY THE LEEWARD SIDE OF THE SIERRA NEVADA MOUNTAINS IN THE GENERAL AREA WHERE STANDING LENTICULAR CLOUDS HAD BEEN OBSERVED. NO EVIDENCE WAS FOUND THAT THE PILOT OBTAINED A WEATHER BRIEFING FROM FLIGHT SERVICE OR THE DUAT VENDORS PRIOR TO DEPARTURE. PILOTS FLYING IN THE GENERAL AREA HAD REPORTED AIRSPEED VARIANCES FROM PLUS 60 TO MINUS 40 KTS. AN IN-FLIGHT WEATHER ADVISORY FOR OCCASIONAL MODERATE TURBULENCE WAS IN EFFECT. ABOUT ONE HOUR AFTER THE ACCIDENT THE WEATHER SERVICE ISSUED A SIGMET FOR SEVERE TURBULENCE.
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: airline transport pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 6,984 hours in all; 782 in this make and model; 87 in the last 90 days; 28 in the last 30 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 4,052 hours
- Last inspection: approved inspection programme, December 12, 1992
- Maximum gross weight: 10,325 lb
- Seats: 3
- Landing gear: retractable
- Engine: Garrett 331-5-251K (turboprop); 0 hours total
- Operator: Medic Air, INC.
The flight
- Departed from: RNO Reno NV at 11:23 pm
- Destination: SVE Susanville CA
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Sky: overcast; not recorded
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.