Service difficulty report · Pump · Boeing 777222

Difficulty date
June 12, 2008
Submitted
July 1, 2008
Operation
Air carrier
Aircraft
N775UA
Make and model
Boeing 777222
Aircraft serial
26947
Aircraft time
51,344 hours, 9,609 cycles
Engine
Pwa PW4077
Part
Pump
Part number
0092
Condition
Faulty
Location
Fuel Boost
Stage of operation
IN
How discovered
O
Nature of condition
W, J
Precautionary procedure
O

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

What was found

THE 'FUEL PUMP LT AFT' EICAS MSG DISPLAYED AND LOW PRESS LIGHT ON THE SW. FOUND NO POWER AT PUMP CONNECTOR ON PIN 4 (PHASE B1) SUSPECT RELAY K28123 INOP. REPLACED RELAY K28123 NO HELP. FOUND C PHASE SHORTED TO GROUND, SUSPECT WIRING OR PUMP. T-S BY REMOVING K28123 & CK DK28123 PIN B1 TO PUMP(DM28102) PIN 4 FOR OPEN OR SHORT. POSS BAD CONN DM28102. CHECKED FOR 115 VAC AT DM2 8102 PINS 2,4,6. FOUND NO DISCREPANCIES, SUSPECT L AFT FUEL BOOST PUMP. REPLACED LT MAIN TANK FUEL BOOST PUMP HOUSING. AFTER LEAK AND OPERATIONAL CHECK, NO LEAKS NOTED, OPS GOOD, NO EICAS MESSAGE.