Service difficulty report · Bearing · Amd FALCON50MYST

Difficulty date
April 16, 2002
Submitted
June 3, 2002
Operation
Air carrier
Aircraft
N138M
Make and model
Amd FALCON50MYST
Aircraft serial
274
Engine
Garrtt TFE7312B
Part
Bearing
Part number
410965
Part serial
MC16923
Condition
Stiff
Location
Starter Gen
Part time
252 hours
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

STARTER-GEN WAS TEMPORARILY REMOVED FROM SERVICE FOR A PRECAUTIONARY BEARING INSPECTION. TSO OF STARTER-GEN WAS 252 HOURS. NEW BEARINGS FROM MFG APPROVED DISTRIBUTOR WERE INSTALLED DURING OVERHAUL. INSPECTION OF SUBJECT BEARING FOUND IT STIFF TO ROTATE AND IT FELT VERY ROUGH WHEN ROTATED. SEALS WERE REMOVED AND GREASE (WHITE COLOR) APPEARED NORMAL. BEARING WAS STILL STIFF AND ROUGH TO ROTATE. BEARING HAD NO RADIAL CLEARANCE, AND THE INNER RACE WAS OVERHEATING AS INDICATED BY LOCALIZED DARK PURPLE TO LIGHT BLUE COLOR. THE ARMATURE SHAFT SHOWED NO SIGNS OF THE RACE SPINNING. THE COLOR OF THE BEARING RETAINERS ALSO INDICATED OVERHEATING. A NEW BEARING WAS INSTALLED AND THE PART WAS RETURNED TO SERVICE.