Service difficulty report · Controller

Difficulty date
April 27, 2012
Submitted
September 14, 2015
Operation
General aviation
Engine
Pwc PT6C67C
Part
Controller
Condition
Malfunctioned
Location
Engine
Stage of operation
NR
How discovered
9
Nature of condition
O
Precautionary procedure
O

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

What was found

(CAN) EXPERIENCED AN IFSD, NP PROP DROPPED TO 500 RPM, DURING PRODUCTION TESTING OF THE PC-12 WITH ENGINE RY0363 INSTALLED. DURING TODAY`S TROUBLESHOOTING THE ROOT CAUSE OF THE PROBLEM WAS CONFIRMED TO BE AN INCORRECT REVERSE PUSH/PULL CABLE ASSY IN PRODUCTION. IT LOOKS LIKE THE ITEM 20, SKETCH BELOW WAS INCORRECTLY ASSEMBLED WITH ITEM 21, CROSSTHREADED. SUCH INSTALLATION WOULD ALLOW THE FOOTBALL, ITEM 5, NOT SEATING CORRECTLY INSIDE ITEM 20. BY SUCH INSTALLATION THE BETA VALVE WAS PUSHED FORWARD, TOWARDS FEATHER. IT IS SUSPECTED THAT AFTER MULTIPLE REVERSE POWER UTILIZATION THE BETA VALVE MOVED FORWARD SUFFICIENT TO FEATHER THE PROP. MFG DEMONSTRATED IT ON GROUND WHEN AS SOON AS THE PLA IS MOVED FORWARD FROM IDLE THE PROP WOULD FEATHER. THE THREAD DAMAGE AND BETA VALVE NOT IN FLASH POSITION.