LAX02LA257 · Air Tractor AT-301
Air Tractor AT-301 · Accident: airframe, component or system failure en route
From Dos Palos, CA (private airstrip) to Dos Palos, CA (private airstrip)
Event
- NTSB case
- LAX02LA257
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Air Tractor AT-301
- Aircraft type
- Air Tractor AT-301
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N8793S
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Dos Palos, CA (private airstrip)To Dos Palos, CA (private airstrip)
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 137: Agricultural
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Propeller system/accessories, blade › Fatigue
- Propeller system/accessories, blade › Separation
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
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.
Probable cause
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX02LA257
- Event ID
- 20020829X01488
- Case number
- LAX02LA257
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 402bc5d89357052151b875c2e55326234c64daabb99d4524ae8854c73d8864b2; retrieved 2026-09-22T10:26:44.998Z.