Amateur-built Glasair SH-2 accident near San Luis Obispo, California, March 21, 2004
On March 21, 2004 at about 8:43 pm local time, a amateur-built Glasair SH-2, registered N309TS, was substantially damaged in an accident near San Luis Obispo, California (San Luis County Regional Airpo airport). 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
The loss of engine power due to the failure of the #3 cylinder piston and connecting rod for undetermined reasons.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 21, 2004 · about 8:43 pm local time
- Place
- San Luis Obispo, California · San Luis County Regional Airpo · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built Glasair SH-2
- Registration
- N309TS · registry record · serial 309
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane experienced a loss of engine power and impacted a ditch during the pilot's forced landing in a field. While approaching the proximity of the destination airport, the pilot observed the engine gauges indicating rising oil temperature. About 5 miles from the airport, the engine emitted a loud noise and he declared an emergency due to an engine failure. Realizing that he would be unable to make it to the runway, the pilot executed a forced landing in a field; during the landing roll, the airplane impacted a ditch and tumbled. Post-accident external visual examination by a Federal Aviation Administration (FAA) inspector revealed that the engine sustained a catastrophic failure, with a hole knocked in the upper case spine above the rear cylinders. Looking through the hole, the inspector observed that the right rear piston had seized in the No. 3 cylinder and its respective connecting rod was broken just above crankshaft rod end flare. The inspector could not identify the rod end cap or the bearing shells. The No. 3 piston skirt was visibly scorched in the direction of piston travel. A visual examination of the engine, disclosed that all of the cylinders were worn and scored. After the accident, the owner took the engine to a maintenance facility that examined the engine and reported that rod bearing in the No. 3 cylinder failed. The facility declined to provide detailed observations on the internal condition of the engine, the rod fracture, and condition of the bearing. The FAA inspector said the pilot told him that prior to the accident, the engine was experiencing excessive oil consumption. In response, the pilot removed the No. 3 cylinder from the engine and employed an engine shop to change the piston in an effort to alleviate the excessive oil consumption problems. After the maintenance was preformed, the pilot reinstalled the cylinder. The inspector added that sometime prior to the accident the pilot had also modified the engine by installing larger pistons.
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, flight instructor, commercial pilot, flight engineer
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 37,000 hours in all; 1,692 in this make and model; 310 in the last 90 days; 100 in the last 30 days; 36,000 as pilot in command
- Last flight review: February 26, 2004
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 1,691 hours
- Last inspection: 100-hour inspection, January 25, 2004; 26 hours since
- Maximum gross weight: 2,200 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming IO-360-A1B (piston); 0 hours total
The flight
- Departed from: CRO Corcoran CA at 8:15 pm
- Destination: SBP San Luis Obispo CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 290° at 9 knots
- Visibility: 9 statute miles
- Sky: scat at 1,200 ft
- Temperature: 63°F (17°C), dew point 55°F (13°C)
- Altimeter: 30.06 inHg
- Observation at 8:46 pm from SBP, 1 miles away
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.