Service difficulty report · Governor · Amtr TAILWINDW8

Difficulty date
May 25, 2011
Submitted
June 20, 2011
Operation
General aviation
Aircraft
N104D
Make and model
Amtr TAILWINDW8
Aircraft serial
A101
Part
Governor
Part number
3482801
Part serial
4148B
Condition
Failed
Location
Engine
Part time
400 hours
Stage of operation
CL
How discovered
O
Nature of condition
O
Precautionary procedure
A

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

What was found

UPON REMOVAL OF THE GOVERNOR HEAD IT WAS DISCOVERED THAT THE PILOT VALVE ASSEMBLY EXPERIENCED A CATASTROPHIC FAILURE. THE PILOT VALVE IS ASSEMBLED OF THREE COMPONENTS; THE VALVE TUBE AND THE END FITTING WHICH ARE PRESS FITTED TOGETHER AND A SET SCREW WHICH ADDITIONALLY SECURES THE TWO TOGETHER. THE SET SCREW WAS FOUND TO BE MISSING WHICH AIDED IN ALLOWING THE END FITTING TO SEPARATE FROM THE VALVE TUBE. THIS FAILURE ALLOWED THE ROLLER BEARING ASSEMBLY AND THRUST BEARING TO BECOME SEPARATED FROM THE PILOT VALVE ASSEMBLY AND MOVE FREELY ABOUT THE FLYWEIGHT CHAMBER. THIS CAUSED EXTENSIVE DAMAGE TO THE ROLLER BEARING. THE ROLLERS SEPARATED FROM THE BEARING AND WERE FOUND TO BE MISSING. THE FLYWEIGHT CHAMBER SUSTAINED DAMAGE DUE TO THESE PARTS BEING BATTERED ABOUT BY THE SPINNING FLYWEIGHT ASSEMBLY."