Service difficulty report · Drive Shaft · Pilats PC1245

Difficulty date
June 6, 2004
Submitted
June 6, 2006
Operation
General aviation
Make and model
Pilats PC1245
Aircraft time
6,703 hours
Engine
Pwa PT6A67B
Propeller
Hartzl HCE4A3D
Part
Drive Shaft
Part number
5243212161
Condition
Sheared
Location
Nr 2 Generator
Part time
4,797 hours
Stage of operation
CR
How discovered
O
Nature of condition
J
Precautionary procedure
A

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

What was found

ON RETURN, PILOT NOTED GEN 2 FAILURE IN CRUISE AND CONT`D ON TO COMPLETE FLT. NR 1 GEN AUTO COVERS FOR NR 2 GEN WHEN A FAILURE OCCURS. INVESTIGATION BY MX REVEALED SHEARED DRIVE SHAFT FOR NR 2 GEN. SHAFT BROKE AT PROPER SHEAR POSITION WITH NO DAMAGE TO ANY OTHER COMPONENT. CAUSE IS UNCLEAR, BUT THERE IS SOME SCORING ON DRIVESHAFT AT FWD BEARING INNER RACE POSITION. BEARING APPEARS IN GOOD COND W/NO BINDING OR ROUGH SPOTS. GEN 2 ALSO APPEARS IN GOOD MECH CONDITION W/NO BEARING DISTRESS OR DRAG ON ALT SHAFT. IT IS SUSPECTED THAT CYCLE LIFE COULD HAVE POSSIBLE AFFECTED SHAFT LIFE AS LOADS ARE CLOSE TO 100 AMPS AFTER STARTUP TO RECHARGE BATTERIES. ALIGNMENT OF SHAFT LOOKS GOOD, NO GREAT AMT OF SPLINE WEAR A