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NYC03TA138 · Air Tractor 402A

26 Jun 2003 · Pearisburg, VA, United States

USDA Forest Service Air Tractor 402A · Accident: total loss of engine power (mechanical failure) while maneuvering

From New River Valley Airport (PSK) to New River Valley Airport (PSK)

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Narrative check · The NTSB narrative appears to contradict this record's operator. Values are shown as recorded, not corrected; compare with the narrative.

Event

NTSB case
NYC03TA138
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
Government
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 402A

Aircraft type
Air Tractor 402
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
N4506L
Operator
USDA/Forest Service Possible conflict
Onboard fatalities
Unknown
Route
From New River Valley Airport (PSK), Dublin, VATo New River Valley Airport (PSK), Dublin, VA
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
Public Aircraft
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 · turn to reverse direction
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

  • Turbine assembly, turbine blade › Fractured

Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.

NTSB narrative

The Air Tractor was spreading chemical when the pilot observed orange flames and black smoke emitting from the engine exhausts. The engine lost power, he feathered the propeller, and set up for a forced landing in a nearby open field. The airplane touched down, rolled a short distance, and struck embedded rock. The landing gear collapsed, the fuselage was wrinkled, and the propeller separated from the engine. Examination of the PWC PT6A-20 engine revealed several compressor turbine blades had fractured and been released into the engine gas path. The blades also impacted adjacent and downstream components. The compressor turbine blades used in the engine were not approved by PWC; however, they were PMA manufactured with FAA approval. Since engine overhaul, the engine had accumulated 10,978.8 hours and 15,059 cycles. According to the FAA, the PWC recommended overhaul time of 3,600 hours. The airplane was being operated on a USDA Forest Service contact that required the engine to have been overhauled within the manufacturer's specifications. The engine's time since overhaul was not discovered by the Forest Service when they accepted the airplane for use on their contract.

Probable cause

A compressor turbine blade fracture which resulted in a power loss, and forced landing. Factor were the rocks in the landing area, and the operator's decision to operate the engine beyond the engine manufacturer's recommendations for overhaul.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record NYC03TA138
Event ID
20030707X01025
Case number
NYC03TA138
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: d19fe9e3731494031c248e3bece121579ef83f8c066ceeda28fb28f75c97db99; retrieved 2026-09-18T21:17:36.857Z.