Service difficulty report · Shaft

Difficulty date
February 11, 2021
Submitted
February 11, 2021
Operation
General aviation
Aircraft
N512LA
Engine
Pwc PT6A67AG
Engine time
1,742 hours, 1,023 cycles
Part
Shaft
Condition
Flaking
Location
Propeller
Part time
1,742 hours, 1,023 cycles
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 RE-INSTALLATION OF POWER SECTION AFTER WIRE STRIKE, WHILE INSTALLING PROPELLER, THE COATING ON THE FRESHLY OVERHAULED PROPELLER SHAFT WAS FLAKING OFF UNDERNEATH THE WASHERS ON THE PROPELLER RETENTION BOLTS. THE TORQUE SETTING WAS INACCURATE. YOU COULD ACTUALLY HEAR THE COATING CRACKING AND CHIPPING. THIS COATING IS PART OF A PRATT AND WHITNEY SERVICE BULLETIN I WAS TOLD. THE COATING IS VERY SHINY LIKE ENAMEL PAINT. THE APPLIED THICKNESS APPEARED TO BE TOO THICK. PULLED POWER SECTION BACK OFF AND RETURNED TO OVERHAUL FACILITY. I FEEL AS IF THIS WE HAD SENT THIS OUT, THE BOLTS WOULD HAVE LOST THEIR TORQUE. THE REST OF OUR FLEET HAVE A COATING I WAS TOLD CALLED ROCKHARD WHICH IS SIMILAR TO HARD ANODIZING OR GUN BLUING. I WOULD REALLY MONITOR THIS COATING DURING BOLT TORQUEING.