# Accident 19980324010439A: Ayres S2RT34RESTD, Buckeye, AZ, March 24, 1998

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: March 24, 1998, 18:45 local time
- Place: Buckeye, AZ
- Damage: Substantial damage
- Phase of flight: Fcd/Prec Ldg From Cruise
- Operating rules: Agricultural (Part 137)
- Operator: ZFEG
- Location: 33.3805° N, 112.5493° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=33.3805&lon=-112.5493&mi=10
- Aircraft: N4010X, registered now (https://openairdocs.org/aircraft/N4010X) (OpenAirDocs)
- Registry model: Ayres S2R-T34 (registry code 0970106, https://openairdocs.org/model/ayres-s2r-t34) (OpenAirDocs)
- Registry engine: Pratt & Whitney Canada PT6A-60A (registry code 52043, https://openairdocs.org/engine/pratt-whitney-canada-pt6a-60a) (OpenAirDocs)
- Reported make and model: AYRES S2RT34RESTD
- Reported engine: PWA PT6A34
- People aboard: 1
- Fatal injuries: 0
- Pilot flight hours: 5,600 total, 2,800 in this make and model, 80 in the last 90 days
- NTSB investigation: [NTSB LAX98LA129](https://openairdocs.org/ntsb/LAX98LA129) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19980324010439A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

LOST POWER DURING A SPRAY RUN. COLLIDED WITH GROUND. (FROM .4) AN AYRES S2R AIRPLANE LOST POWER AND CRASHED FOLLOWING A LANDING ATTEMPT TO A FIELD.  THE SUBSEQUENT DISASSEMBLY OF THE ENGINE REVEALED THAT THE COMPRESSOR TURBINE DISK WAS INTACT, BUT THAT ALL OF THE CT BLADES WERE FRACTURED ACROSS THE AIRFOILS ADJACENT TO THE BLADE ROOT PLATFORM.  THE CANADIAN TRANSPORTATION SAFETY BOARD'S ENGINEERING BRANCH FOUND THAT THERE WERE 55 BLADES OF ONE PART NUMBER AND 3 BLADES OF ANOTHER PART NUMBER WHICH WERE NOT AUTHORIZED FOR USE IN A PT6A-34AG ENGINE.  THE THREE UNAPPROVED BLADES HAD A DIFFERENT HEAT CODE THAN WAS APPROVED FOR THIS ENGINE.  ONE OF THE UNAPPROVED BLADES REVEALED A FATIGUE FRACTURE ON THE SURFACE AS SEEN BY THE SCANNING ELECTRON MICROSCOPE.  THE BLADES WERE MANUFACTURED BY DONCASTER, UNDER A FAA PARTS MANUFACTURING APPROVAL AS AN ALTERNATE PART FOR PWC CT BLADES.  THEY WERE THEN PACKAGED AND SHIPPED TO SUPERIOR AIR PARTS.  SUPERIOR AIR PARTS WOULD REPACKAGE THE BLADES IN SUPERIOR AIR PARTS PACKAGING PRIOR TO RESHIPPING THE BLADES.  DONCASTER'S STATED THAT SUPERIOR WAS THE SOLE DISTRIBUTOR OF THE DONCASTER BLADES.  BOTH THE QUALITY CONTROL STANDARDS AT SUPERIOR AIR PARTS  AND AIR FORCE TURBINE SERVICES DID NOT NOTICE THE THREE INCORRECT CT BLADES, WHICH WERE SHIPPED FROM SUPERIOR AIR PARTS AND SUBSEQUENTLY, INSTALLED ON THE ENGINE. ADDITIONALLY, WHEN THE ENGINE UNDERWENT REPAIR WORK AND THESE BLADES WERE INSTALLED, THE NEW CT BLADES WERE INSTALLED AND THE RADIAL TIP CLEARANCE BETWEEN THE BLADES AND SEGMENTS WAS 0.0025 INCHES LESS THAN THE MINIMUM REQUIRED BY THE PT6 ENGINE MANUAL.                                 (-23) ON PART 137 FLIGHT COMPRESSION TURBINE BLADE FAILED, POWER TURBINE WAS SEVERLY DAMAGED. AIRCRAFT LOST POWER AND LANDED IN A FIELD

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB LAX98LA129](https://openairdocs.org/ntsb/LAX98LA129), Mar 25, 1998: Ayres S2RT-34RE (N4010X), Buckeye, AZ, substantial damage. Probable cause: The incorrect turbine blades installed on the engine, the fractured compressor turbine blades and separation of the blade, and the improper maintenance installation of the incorrect CT blades by the…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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