Service difficulty report · Gear · Casa C212CC

Difficulty date
February 12, 2008
Submitted
March 19, 2008
Operation
General aviation
Aircraft
N961BW
Make and model
Casa C212CC
Aircraft serial
248
Engine
Garrtt TPE33110R
Part
Gear
Part number
8937396
Part serial
05P17337
Condition
Broken
Location
Gear Box
Part time
2,170 hours
Component
Gear Box
Component part number
310180729C
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

ENGINE RECEIVED WITH BROKEN FEATHER VALVE, NOSE CONE NUTS LOOSE, ROTATION OF ENGINE ROTATING COMPONENTS FOUND CLUNKY AND SEIZED. MAGNETIC PLUG CONTAMINATED WITH FINE METAL PARTICLES. NOSE CONE AND DIAPHRAGM REMOVED TO INVESTIGATE CAUSE OF FAILURE. WHEN DIAPHRAGM ASSY WAS REMOVED BIG CHUNKS OF METAL NOTICED AT THE GEARBOX CAVITY IDENTIFIED AS BULL GEAR PIECES. HIGH SPEED PINION GEAR HELICAL TEETH BROKEN OFF AND CRUNCHED. SEVERAL BULL GEAR TEETH BROKEN OFF. BIG PIECE (2-3 INCH) OF GEAR RIM MISSING AND FOUND TRAPPED BETWEEN DIAPHRAGM HOUSING AND SCAVENGE PUMP CAUSING A RUPTURE OF THE PUMP HOUSING. THE PRELIMINARY REASON FOR THE GEAR BOX FAILURE IS BELIEVED TO BE CAUSE BY BULL GEAR FAILURE. THE SEPARATION OF THE BULL GEAR RIM HAS CAUSED A SUDDEN STOPPAGE OF THE GEAR TRAIN TO THE PROPELLER RESULTING IN THE DAMAGE OF THE HSP HELICAL GEAR. MFG HAS BEEN CONTACTED AND FURTHER INVESTIGATION WILL BE REQUIRED TO CONFIRM PRELIMINARY CONCLUSION. (K)