SDR 99ZZZX558

Service difficulty report · Bearing · Boeing 747*

Difficulty date
August 18, 1998
Submitted
March 26, 2000
Operation
General aviation
Make and model
Boeing 747*
Engine
Pwa JT9D7A
Part
Bearing
Part number
754380
Condition
Spalled
Location
Nr 2
Part time
367 hours
Stage of operation
IN
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

THE ENGINE WAS REMOVED FROM SERVICE 367 HOURS/155 CYCLES SINCE HEAVY REPAIR DUE TO METAL BEING PICKED UP ON THE MAGNETIC CHIP DETECTOR (ANGLE GEARBOX). THIS METAL IDENTIFIED AS BEING BEARING CAGE MATERIAL. STRIP OF THE BEARING WAS FOUND WITH HEAVY WEAR IN ALL CAGE POCKETS AND SPALLING/PITTING IN 70 PERCENT OF POCKETS. THIS BEARING IS OF THE TYPE THAT HAVE TEN DIGIT SERIAL NUMBERS THAT WERE INTRODUCED IN SEPT 97.