Service difficulty report · Drive Gear · Boeing 767322

Difficulty date
November 6, 2002
Submitted
December 16, 2002
Operation
Air carrier
Aircraft
N658UA
Make and model
Boeing 767322
Aircraft serial
27113
Aircraft time
43,695 hours, 7,186 cycles
Engine
Pwa PW4060
Engine time
47,567 hours, 7,501 cycles
Part
Drive Gear
Part number
70R555
Part serial
66
Condition
Sheared
Location
Oil Pump
Stage of operation
CR
How discovered
O
Nature of condition
K, M
Precautionary procedure
E, A

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

NR 1 ENGINE SHUTDOWN DUE TO LOSS OF OIL PRESSURE AND HIGH TEMP. OIL PUMP DRIVE GEAR FAILURE. OIL PUMP DRIVE BEARING AND GEAR ASSY WERE FOUND LOOSE AND COCKED IN THE GEARBOX BEARING BORE. BEARING RETAINING SCREWS (ITEM 10 ) WERE BACKED OUT OF THE GEARBOX HOUSING AND LAYING IN THE BOTTOM OF THE GEARBOX. THIS RESULTED IN FRACTURE OF THE OIL PUMP DRIVE MODULE GEAR SHAFT IN THE WEB OF THE GEAR. THE FINAL ROOT CAUSE IS STILL BE INVESTIGATED. ENGINE WILL REQUIRE OVERHAUL OF ALL BEARINGS DUE TO LOSS OF OIL PRESSURE. MAIN GEARBOX WILL BE OVERHAULED.