Amateur-built GLASSAIR III accident near Guistine, California, November 19, 2000
On November 19, 2000 at about 8:00 pm local time, a amateur-built GLASSAIR III, registered N540AK, was substantially damaged in an accident near Guistine, California. It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Maintenance personnel misrouted the crankcase breather hose so that it was pinched when the cowling was installed. This pressurized the crankcase displacing the oil seal and forcing oil out of the engine. A factor was the unsuitable terrain encountered during the forced landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 19, 2000 · about 8:00 pm local time
- Place
- Guistine, California · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built GLASSAIR III GLASSAIR I
- Registration
- N540AK · no longer on the register · serial 3077
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane nosed over during a forced landing after the pilot encountered smoke in the cockpit. Oil was spewing onto the windshield, the engine was losing oil pressure, and smoke was filling the cockpit. The pilot made an emergency landing on an abandoned dirt strip that was about 1,400 feet long. However, the airplane overran the runway into a ravine and overturned. Maintenance that had been completed the day before the accident included an oil change and replacement of the crankshaft nose seal; a run-up had revealed no oil leaks. The engine sustained no visible damage resulting from the forced landing, and visual examination revealed no evidence of catastrophic mechanical malfunction or fire. A significant amount of engine oil emanated from the nose cowling where the engine and propeller flange protruded. The oil film proceeded aft onto the windscreen as well as the horizontal and vertical stabilizers. The spark plugs, cylinder walls, valves, and pistons exhibited no mechanical damage. Oil lines within the engine compartment were secure on their fittings. The propeller governor was secure and not leaking. The oil filter and oil filter converter plate were properly installed and secure. There were no visible contaminates in the oil filter or suction screen. The propeller was removed, but there was no evidence of oil leakage at the propeller seal. The crankshaft oil seal was out of its bore and resting on the crankshaft. One oil ring was cracked, but no compression rings were broken. There was evidence of overheating from running lean. The breather hose had been mounted over the motor mount rather than under it. In this location the hose was pinched when the cowling was installed. This plugged the breather hose and pressurized the case, forcing oil out through the front seal.
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: multi-engine land; single-engine land; instrument: airplane
- Flight time: 2,300 hours in all; 700 in this make and model; 30 in the last 90 days; 10 in the last 30 days; 2,300 as pilot in command
- Last flight review: June 18, 2000
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: left
- Injury: serious injuries
The aircraft
- Airframe total time: 700 hours
- Last inspection: 100-hour inspection, November 18, 2000; 2 hours since
- Maximum gross weight: 2,500 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming IO540-K1G5D (piston); 0 hours total
The flight
- Departed from: 3O1 Guistine CA at 7:35 pm
- Destination: RHV San Jose CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 320° at 5 knots
- Visibility: 10 statute miles
- Sky: scat at 25,000 ft
- Temperature: 55°F (13°C), dew point 39°F (4°C)
- Altimeter: 30.00 inHg
- Observation at 7:50 pm from RHV, 22 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.
Other NTSB records under N540AK the same tail number, which may have belonged to a different aircraft at the time
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.