Service difficulty report · Freq Adapter · Urocop EC130B4

Difficulty date
February 4, 2008
Submitted
April 7, 2008
Operation
Air carrier
Aircraft
N817MH
Make and model
Urocop EC130B4
Aircraft serial
4125
Engine
Tmeca ARRIEL2B
Part
Freq Adapter
Part number
350A31182703
Part serial
10173
Condition
Cracked
Location
Main Rotor Head
Part time
1,199 hours
Component
Main Rotor Head
Component part number
355A31000201
Stage of operation
IN
How discovered
V
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 ROUTINE 100 HOUR INSPECTION, A CRACK IN THE BLUE BLADE ELASTOMER WAS FOUND ON THE T/E LWR IB SURFACE RADIATING FROM THE INSPECTION BORE. THIS CRACK HAD REACHED THE MM LIMITATION OF 10MM IN TOTAL LENGTH. THIS IS A VERY COMMON FAILURE FOR A PART WITH A NEWLY PUBLISHED 20000 HOUR LIVE LIMIT. THE ORIGINAL LIFE LIMIT WAS 3000 HOURS WHICH NONE OF THESE PARTS HAVE EVER LASTED. MFG EXPLANATION WAS THAT THE LIMIT WAS FOR THE METAL COMPONENTS OF THE PART. THE ELASTOMER FORMULATION OF THE ORIGINAL PN WHICH HAD BEEN REPLACED BY THE CURRENT PN ALMOST NEVER FAILED. MFG HAS BEEN NOTIFIED OF BOTH THESE DETAILS WITH NO ACTION TAKEN. (K)

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