SDR 95ZZZX5654

Service difficulty report · Turbine Disk

Difficulty date
September 22, 1995
Submitted
March 26, 2000
Operation
General aviation
Engine
Pwa JT8D17R
Part
Turbine Disk
Part number
786822A
Condition
Fir Tree Failure
Location
2nd Stage
Part time
18,729 hours
Stage of operation
IN
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DURING DEBLADING OF THE SECOND STAGE TURBINE DISK, 3 FIR TREES FELL OFF WHEN THE BLADES WERE REMOVED. OVERHAUL MANUAL PROCEDURES WERE FOLLOWED AND WERE NOT A CONTRIBUTING CAUSE TO THE DAMAGE. THE CRACKS ON THE FIR TREES APPEAR TO BE OLD DUE TO SOOT DEPOSITS. THE OEM (PRATT & WHITNEY) NOTIFIED ON 9-21-95. GAS TURBINE COMPANY CONTROL ORDER IS 11730E.