CEN16LA154 · Air Tractor Inc AT 502
Pioneer Flying Service Air Tractor Inc AT 502 · Accident: aircraft structural failure while maneuvering
From PRI · Pioneer, LA to PRI · Pioneer, LA
Event
- NTSB case
- CEN16LA154
- 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
- 1 · 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 Inc AT 502
- Aircraft type
- Air Tractor AT-502
- 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
- N301LA
- Operator
- Pioneer Flying Service
- Onboard fatalities
- Unknown
- Route
- From PRI · Pioneer, LATo PRI · Pioneer, LA
- Aircraft age
- About 27 years (built 1989)
- 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 · low-altitude flying
- Defining eventThe 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
- Aircraft structural failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Aircraft › Aircraft structures
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
**This report was modified on March 23, 2026. Please see the docket for this accident to view the original report.** The commercial pilot was conducting his second spray load application of the day to a field located about 1/4 mile north of the accident site. A farmer stated that the pilot's last passes were to finish spraying a tight area of the field that had trees at the end. A witness near the accident site saw the airplane turn at low altitude and then rapidly descend until ground impact. The airplane was destroyed by impact forces and a postimpact fire. Postaccident examination of the wreckage and ground scars revealed that the airplane impacted terrain in a steep, nose-down attitude. Examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The pilot had hypertension and left ventricular hypertrophy (LVH). However, it is unlikely that the pilot's underlying hypertension and LVH contributed to the accident. In December of 2025, the vertical stabilizer of the airplane was located in a wooded area northeast of the location where the main wreckage came to rest. Metallurgical examination of the vertical stabilizer revealed fractured surfaces on both fitting lobes with extensive post-fracture smearing damage. Thumbnail shaped areas contained macro features consistent with fatigue cracking which emanated from the forward face of the attach plate. A service letter and airworthiness directive required periodic examination of the vertical fin front spar fitting for cracks with the installation of the steel doubler as a “terminating action.” There was no evidence that the steel doubler had been installed. Maintenance records for the accident airplane were not made available, and investigators were unable to determine if the periodic examination for cracks was accomplished. It is most likely that the vertical stabilizer separated during the aerial application flight due to the progressive fatigue cracking within the front spar fitting. This separation resulted in a loss of airplane control and subsequent impact with terrain.
Probable cause
The failure of the operator to comply with the terminating action of the airworthiness directive, which resulted in the subsequent failure and separation of the vertical stabilizer due to fatigue.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN16LA154
- Event ID
- 20160418X51924
- Case number
- CEN16LA154
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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, cause areas. 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: cb0320f64bca0b143ad34aaef95a8caaa5ef668954a70a0323cc3f22b647b00c; retrieved 2026-09-14T21:44:30.968Z.