Service difficulty report · Coupling

Difficulty date
September 2, 2003
Submitted
February 6, 2004
Operation
General aviation
Engine
Allsn 250C20B
Part
Coupling
Part number
23039791C
Condition
Cracked
Location
Compressor
Stage of operation
NR
How discovered
V
Nature of condition
O
Precautionary procedure
O

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

What was found

DETECTED CRACK VIA VISUAL AND MPI INSPECTIONS DURING ROUTINE INSPECTION OF COMPRESSOR MODULE, COMPRESSOR ROTOR ASSEMBLY. DISASSEMBLED FOR INSPECTION OF FUTURE INSTALLATION. NOTED HEAVY FRETTING WEAR ON COUPLING ADAPTER OD TO IMPELLER ID FIT DIMENSION. THE CRACK EXTENDS APPROX 60 PERCENT OF THE OUTSIDE DIAMETER OF THE PART. THE CRACKING IS POSSIBLY DUE TO THE FRETTING WEAR ON THE ADAPTER OD.