Schweizer 269C accident near Los Banos, California, December 18, 2002
On December 18, 2002 at about 11:21 pm local time, a Schweizer 269C (helicopter), registered N642KC, was substantially damaged in an accident near Los Banos, California (Los Banos airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The improper engine overhaul by other maintenance personnel, which resulted in an exhaust valve failure and a total loss of engine power while in maneuvering flight.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 18, 2002 · about 11:21 pm local time
- Place
- Los Banos, California · Los Banos · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Schweizer 269C · all 269Cs on the register
- Registration
- N642KC · no longer on the register · serial S1682
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot and aircraft maintenance technician were performing a post maintenance test flight when a vibration occurred, followed by a total loss of engine power. The commercial certificated helicopter pilot made a forced landing in a muddy field, during which the helicopter received structural damage. Post accident examination revealed a failed exhaust valve in the number 3 cylinder, and that two exhaust spring seats had been installed, one on top of the other, causing excessive spring/valve pressures. The engine had been overhauled about 1.5 service hours prior to the loss of engine power.
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, private
- Ratings: single-engine land; instructor: helicopter; rotorcraft: helicopter
- Flight time: 1,900 hours in all
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 3,784.6 hours
- Last inspection: 100-hour inspection, August 23, 2002; 1.5 hours since
- Maximum gross weight: 2,050 lb
- Seats: 2
- Landing gear: fixed
- Engine: Avco Lycoming HIO-360-D1A (piston); 0 hours total
The flight
- Departed from: LSN Los Banos CA at 11:00 pm
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 010° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 54°F (12°C), dew point 37°F (3°C)
- Altimeter: 30.20 inHg
- Observation at 10:53 pm from MCE, 22 miles away
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.