Service difficulty report · Planetary Gear

Difficulty date
January 28, 2005
Submitted
March 3, 2005
Operation
General aviation
Engine
Pwa PT6A50
Part
Planetary Gear
Condition
Failed
Location
Engine Rgb
Part time
21,873 hours, 20,838 cycles
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) SOURCE OF METAL CONTAMINATION WAS FAILURE OF 1ST STAGE GEARS. GEARS WERE SENT TO METALLURGICAL LABORATORY FOR FURTHER INVESTIGATION THAT REVEALED THE EXISTENCE OF AN OLDER FATIGUE CRACK SURFACE ON PARTS OF A FRACTURED TOOTH ON THE 1ST STAGE SUN GEAR, SUN GEAR. PARTS OF THIS GEAR BROKE OFF IT IS BELIEVED THEY BECAME WEDGED BETWEEN THE SUN GEARE & THE 1ST STAGE PLANETARY GEAR CAUSING THE PLANET GEAR TOOTH TO SHATTER. SINCE DAMAGE TO RGB GEARING SIGNIFICANT, DECIDED TO PERFORM FULL OVERHAUL LEVEL INSPECTIONS ON ALL RGB COMPONENTS, CLEAN & FLUSH & VISUALLY INSPECT REMAINING POWER SECTION COMPONENTS & TO CLEAN FLUSH & VISUALLY INSPECT OIL WETTED COMPONENTS UPSTREAM OF MAIN PRESSURE FILTER.