Boeing A75N1 accident near Tracy, California, July 29, 1996
On July 29, 1996 at about 1:15 pm local time, a Boeing A75N1, registered N68251, was destroyed in an accident near Tracy, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A loss of engine power due to the disengagement of the crankshaft gear from it's hub due to the overload shear of the eight retaining screws.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 29, 1996 · about 1:15 pm local time
- Place
- Tracy, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing A75N1 A75-N1 · all A75N1s on the register
- Registration
- N68251 · no longer on the register · serial 75-7976
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that the engine quit while he was en route to a job and he landed in an alfalfa field. The aircraft collided with a ditch which was obscured by the crops. A postcrash fire erupted and consumed the aircraft. The aircraft was examined by an FAA airworthiness inspector. He reported that the engine crankshaft would rotate; however, no corresponding valve action was noted on any cylinder. The inspector observed a disassembly of the engine and reported that the eight screws which secure the crankshaft hub to the crankshaft gear had sheared. The crankshaft gear rotates all accessory drive gears, including the magnetos.
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: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 4,700 hours in all; 1,030 in this make and model; 150 in the last 90 days; 85 in the last 30 days; 4,450 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 3,779 hours
- Last inspection: annual inspection, June 26, 1996; 85 hours since
- Maximum gross weight: 3,500 lb
- Seats: 1
- Landing gear: fixed
- Engine: Wright R-975-11 (piston); 0 hours total
- Fire on the ground
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 0°F (-18°C)
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.