SDR 0720064020

Service difficulty report · Pulley · Urocop EC130B4

Difficulty date
July 21, 2006
Submitted
August 22, 2006
Operation
Air carrier
Aircraft
N814MH
Make and model
Urocop EC130B4
Aircraft serial
4020
Engine
Tmeca ARRIEL2B
Part
Pulley
Part number
350A35109220
Condition
Worn
Location
Hyd Pump
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

ON INSP, QUITE A BIT OF DARK DUST HAD ACCUMULATED UNDER HYD PUMP DRV ASSY MOUNTING, THOUGHT TO BE ROTOR BRAKE DUST ACCUMULATION. DRV PULLEY APPEARED TO BE CORRECTLY ALIGNED, UPON LOOSENING, PULLEY WAS FOUND TO WOBBLE LIKE A U-JOINT. UPON TEARDOWN, FOUND CTR SHAFT ON PULLEY WHERE INNER RACE OF BRG IS PRESSED WAS SEVERELY WORN, BRG ALIGNMENT THAT DID EXIST WAS DUE TO SNAP RING, PN S-40 COUPLING. DRIVING HYD PUMP, GUIDING BRG INNER RACE. SUSPECT THAT AN INADEQUATE OUTSIDE DIMENSION ON PULLEY CTR SHAFT MAY HAVE CAUSED INITIAL SLIPPAGE OF BRG INNER RACE DUE TO HEAT EXPANSION OF BRG, SUBSEQUENT LOSS OF PRESS FIT. BRG INNER RACE THEN SLIPPED AND SKIDDED AND CHATTERED CAUSING WEAR WHICH EXCEEDED . 150 INCH. (K)

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