Service difficulty report · Scavenge Pump · Boeing 747422

Difficulty date
January 15, 2011
Submitted
February 11, 2011
Operation
Air carrier
Aircraft
N171UA
Make and model
Boeing 747422
Aircraft serial
24322
Aircraft time
80,303 hours, 9,593 cycles
Engine
Pwa PW4056
Part
Scavenge Pump
Part number
RR24680A
Part serial
816
Condition
Faulty
Location
Center Tank
Stage of operation
NR
How discovered
O
Nature of condition
J
Precautionary procedure
O

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

What was found

CTR TANK DID NOT SCAVANGE COMPLETELY, .8 USEABLE FUEL AFTER PUMP OFF. AIR MODE SCAVENGE SYST TEST FAILED. SCAVANGE PUMP WAS REPLACED AND LEAKED CHECKED. SCAV PUMP CB PULLED & COLLARED IN P414 PANEL. THIS SCAVG TEST WILL TAKE APPPOX 3-4 HRS. ADJUSTED TO REFLECT TIME REMAINING ON DF155 ORIGINALLY. DEFERRED ON 04JAN11. REPLACED SINGLE POINT SENSOR CONTROL CARD A2. OPS CHECKED GOOD. DID CTR WING TANK SCAVENGE SYS TEST. RANG OUT WIRES FROM P.180 TO RELAY R296. ALSO FROM RELAY R296 TO DM810 PUMP CONNECTOR REF WD, ALL CHECKED NORMAL. RAN CTR WING TANK SCAVENGE SYS TEST IN AIR MODE. TEST PASSED.