Service difficulty report · Thrust Bearing

Difficulty date
August 12, 2015
Submitted
April 22, 2016
Operation
General aviation
Engine
Garrtt TPE331*
Part
Thrust Bearing
Part number
1415336
Condition
Damaged
Location
Csd
Stage of operation
NR
How discovered
9
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

(CAN) DURING PRODUCTION ACCEPTANCE TESTING, THE THRUST BEARING, 1415-336 WAS FOUND TO EXHIBIT EXCESSIVE WEAR AFTER 1.5 HR TEST PERIOD. THIS BEARING IS USED IN CONTROLLING THE SPEED IN THE OPERATION OF THE CSSA GOVERNOR, CONSTANT SPEED SINGLE ACTING, CSSA, PROPELLER GOVERNORS. MFG PN 3105716-5, 897410-16, 897410-4. INSPECTION INDICATES THE RACEWAY OF THE BEARING ON A SPECIFIC LOT WAS MACHINED INCORRECTLY. THIS CONDITION CAUSED THE BALL RETAINER FOR THE BEARING TO WEAR. GOV MFG HAS ISOLATED THE LOT AND IS INVESTIGATING THE CAUSE OF THE MFG ERROR THERE HAS BEEN NO IN-FLIGHT OPS INCIDENTS REPORTED WHERE THIS NON CONFORMANCE HAS BEEN INVOLVED. GOV MFG IS REQUESTING REPAIR STATIONS AND OPERATORS TO CONTAIN INVENTORY OF THE HARDWARE UNTIL A RECOMMENDATION CAN BE MADE REGARDING DISPOSITION OF THIS HARDWARE. MFG HAS INITIATED LIFE TEST AND FAILURE MODES AND EFFECTS OF THIS CONDITION ON OPERATION IN ORDER TO PROVIDE A FIELD RECOMMENDATION.