ASN Wikibase Occurrence # 354675
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Tuesday 24 March 1998 |
| Time: | 19:45 LT |
| Type: |  Ayres S-2R-T34 Turbo Thrush |
| Owner/operator: | Pierce Aviation |
| Registration: | N4010X |
| MSN: | 6024 |
| Year of manufacture: | 1979 |
| Total airframe hrs: | 9708 hours |
| Engine model: | P&W PT6A-34 |
| Fatalities: | Fatalities: 0 / Occupants: 1 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | Buckeye, AZ -
 United States of America
|
| Phase: | En route |
| Nature: | Ferry/positioning |
| Departure airport: | Buckeye, AZ (KBXK) |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
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.
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 repair station. A factor in the accident was the inadequate quality control procedures by both the shipper of the CT blades and the maintenance facility which installed the blades.
Accident investigation:
 |
|
Sources:
NTSB LAX98LA129
History of this aircraft
Other occurrences involving this aircraft
| 2 August 2022 | N4010X | Crop Dusters LLC | 0 | Le Mars, IA | |
unk |
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 11-Mar-2024 17:06 | ASN Update Bot | Added |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2024 Flight Safety Foundation