Service difficulty report · Housing · Boeing 777222

Difficulty date
September 18, 2004
Submitted
September 28, 2004
Operation
Air carrier
Aircraft
N791UA
Make and model
Boeing 777222
Aircraft serial
26933
Aircraft time
31,238 hours, 4,872 cycles
Engine
Pwa PW4090
Part
Housing
Condition
Leaking
Location
Nr 2 Gearbox
Stage of operation
NR
How discovered
9
Nature of condition
K, J
Precautionary procedure
O

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

What was found

NR 2 ENGINE LOSS OF OIL PRESS/QUANTITY, TEMP INCRG/PRESS DCRSG. AMBER ALERT DECLARED FOR EMERGENCY EQUIPMENT, AFCT LANDED NORMALLY. FOUND MEATL ON THE MAIN & ANGLE GEARBOX (AGB) CHIP DETECTOR. THE ENGINE WAS REPLACED IN SEA. (NOTE: THE MASTER MCD HAD CHECKED CLEAN AT ORD, IMMEDIATELY PRIOR TO THIS FLIGHT.) AT TEARDOWN, THE AGB HOUSING WAS FOUND LEAKING FROM A CRACK. ADDITIONALLY, THE AGB SHOWED HEAVY SIGNS OF COKING AND HEAT DISTRESS. THE AGB HAD ONLY BEEN INSTALLED FOR 214 HOURS (32 CYCLES). THE PRIOR AGB ON THIS ENGINE HAD SUFFERED SIMILAR COKING AND HEAT DISTRESS. IN SPITE OF ALL ENGINE MODULES HAVING BEEN DISASSEMBLED, NO ROOT CAUSE WAS FOUND.