Air Tractor AT-301 accident near Dos Palos, California, August 22, 2002
On August 22, 2002 at about 2:30 pm local time, a Air Tractor AT-301, registered N8793S, was substantially damaged in an accident near Dos Palos, California (Dos Palos Airport). 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
the failure of the propeller blade due to fatigue. Factors in the accident were the inadequate maintenance-repair of the blade, and, inadequate pilot preflight inspections.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 22, 2002 · about 2:30 pm local time
- Place
- Dos Palos, California · Dos Palos Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor AT-301
- Registration
- N8793S · no longer on the register · serial AT 301-0195
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
During cruise flight the engine started to vibrate and the pilot made a forced landing in a newly plowed field and the airplane nosed over after encountering soft soil. The pilot had been crop dusting for about 7.5 hours when the event occurred. The outboard portion of one of the propeller blades had separated. A review of the airframe records indicated that the propeller was overhauled about 10 months prior to the accident. A metallurgical examination of the failed blade revealed it had failed as a result of fatigue cracking that originated from a nick, located on the flat side of the blade's leading edge. Also observed were groove marks that were relatively uniform and consistent with tool marks left by a file. In accordance with the overhaul manual, a field repair can be done to grind or file out corrosion of the blade, with a dye penetrant inspection to detect any visible damage or cracks (Hamilton Standard 130B Blade Overhaul Manual). The overhaul manual notes that tool and file marks should be polished out as one of the final steps in the process. According to the FAA approved flight manual, during the preflight walk-around inspection, the pilot is to inspect the propeller blades for nicks and cracks.
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: single-engine land
- Flight time: 18,542 hours in all; 16,000 in this make and model; 300 in the last 90 days; 125 in the last 30 days; 18,542 as pilot in command
- Last flight review: November 15, 2001
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: ctr
- Injury: no injuries
The aircraft
- Airframe total time: 13,904 hours
- Last inspection: 100-hour inspection, August 8, 2002
- Maximum gross weight: 7,710 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney R1340 (piston); 0 hours total
The flight
- Departed from: PVT Dos Palos CA at 1:50 pm
- Destination: PVT Dos Palos CA
- Flight plan: none
- Runway 290, 2,600 ft by 60 ft
Weather at the time
- Light: daylight
- Wind: from 310° at 4 knots
- Visibility: 3 statute miles
- Sky: clear
- Temperature: 54°F (12°C), dew point 50°F (10°C)
- Altimeter: 29.95 inHg
- Observation at 1:53 pm from MCE, 19 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 N8793S 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.