Service difficulty report · Spline Adapter · Aerosp AS355*

Difficulty date
July 2, 2002
Submitted
July 2, 2002
Operation
Air carrier
Make and model
Aerosp AS355*
Aircraft serial
5495
Engine
Allsn 250C20F
Engine time
4,662 hours, 11,109 cycles
Part
Spline Adapter
Part number
EH230397911
Part serial
UM3053
Condition
Fretted
Location
Compressor
Part time
2 hours, 6 cycles
Component
Compressor · Allsn · 250C20F
Component part number
6890550
Stage of operation
UK
How discovered
O
Nature of condition
J
Precautionary procedure
A

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

What was found

NEW COMPRESSOR SPLINE ADAPTER WAS PURCHASED FROM MANUFACTURER. SERVICE BULLETIN T-069 WAS PACKAGED WITH THE SPLINE ADAPTER, PROVIDING INSTRUCTIONS TO MODIFY THE IMPELLER THAT THE ADAPTER WAS GOING TO BE INSTALLED IN. BULLETIN WAS LATER RECALLED BY MANUFACTURER, CAUSING ENGINE TO BE REMOVED TO REPLACE THE IMPELLER THAT WAS MODIFIED. REMOVAL OF SPLINE ADAPTER AND IMPELLER REVEALED EXCESSIVE WEAR ON OD OF ADAPTER WITH ONLY 3 HOURS OF OPERATION ON IT. ADAPTER AND IMPELLER HAVE BEEN REMOVED AND SENT TO MANUFACTURER FOR INVESTIGATION. THIS EXCESSIVE WEAR HAS BEEN OBSERVED ON SEVERAL OF THE SAME P/N ADAPTERS AFTER REMOVAL FROM ENGINES.