Service difficulty report · Sun Gear

Difficulty date
June 9, 2011
Submitted
September 9, 2011
Operation
General aviation
Engine
Pwa PT6A41
Part
Sun Gear
Part number
3028456
Part serial
31B335
Condition
Chipped
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

OPERATOR REPORTED METAL CONTAMINATION IN THE ENGINE OIL SYS. ACCESS OF THE FIRST STAGE GEAR TRAIN REVEALED THAT THE MAJORITY OF ONE GEAR TOOTH WAS MISSING FROM THE FIRST STAGE SUN GEAR. SEVERAL OTHER FIRST STAGE SUN GEAR TEETH HAD SIGNIFICANT GEAR TOOTH DAMAGE. VISUAL INSPECTION OF THE FIRST STAGE PLANET GEARS REVEALED SOME SECONDARY IMPACT DAMAGE AND DENTING. 1 OF THE 3 GEARS, HAD A PIECE OF EMBEDDED MATERIAL ON ONE GEAR TOOTH THAT APPEARED TO BE A SMALL PIECE OF THE FIRST STAGE SUN GEAR. THE FIRST STAGE RING GEAR HAD ONE GEAR TOOTH THAT WAS CHIPPED AND MISSING MATERIAL.