Service difficulty report · Seal · Robsin R44RAVENII

Difficulty date
March 10, 2011
Submitted
September 14, 2015
Operation
General aviation
Make and model
Robsin R44RAVENII
Aircraft time
969 hours
Engine
Lyc IO540AE1A5
Part
Seal
Part number
C9665
Condition
Failed
Location
Sprag Clutch
Stage of operation
IN
How discovered
9
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

(CAN) WHILE PREFORMING SB-79 AND INSTALLING THE NEW RETAINERS, PN C168-5 ON THE CLUTCH HOUSING. HAD THREE SEALS THAT WERE UNDERSIZED BY 0.010"-0.015" CAUSING THEM NOT TO SEAL AGAINST THE RETAINER. THE PROPER SIZED SEALS ARE AN INTERFERENCE FIT NEEDING TO BE PRESSED INTO THE RETAINERS. THE PROBLEM SEALS CAN BE INSTALLED BY HAND AND REMOVED BY HAND. THE UNDERSIZED SEALS HAVE BEEN REMOVED FROM INVENTORY.