FTW97LA169 · Air Tractor AT-400
Air Tractor AT-400 · Accident: total loss of engine power (mechanical failure) while maneuvering
From Lamesa, TX (no airport) to an unrecorded destination
Event
- NTSB case
- FTW97LA169
- 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
- 0
- 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-400
- Aircraft type
- Air Tractor AT-400
- 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
- N73127
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Lamesa, TX (no airport)To not recorded
- 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
- Maneuvering · aerial application
- 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
- Total loss of engine power (mechanical 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
- Reduction gear assembly › Failure, total
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was performing a swath run when he felt a vibration, and then the engine lost power. A forced landing was initiated to a plowed field. During the landing sequence, the left main landing gear separated from the fuselage, and the right wing spar was bent upward. A teardown inspection of the airplane's engine revealed that the reduction gear box failed and sheared the drive shaft. According to the FAA inspector, 'This failure allowed a turbine over speed to the point that the turbine blades separated from the wheel causing a contained catastrophic failure.'
Probable cause
The loss of engine power due to the failure of the reduction gear box. A factor was the lack of suitable terrain for the forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW97LA169
- Event ID
- 20001208X07715
- Case number
- FTW97LA169
- 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. 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: e19e0b31d54cda24da0d18c088d2143a46169ed7577593a529e4187648829edb; retrieved 2026-09-22T19:55:42.421Z.