Service difficulty report · Sensor · Boeing 777222

Difficulty date
September 10, 2005
Submitted
December 6, 2005
Operation
Air carrier
Aircraft
N796UA
Make and model
Boeing 777222
Aircraft serial
26931
Aircraft time
33,746 hours, 5,098 cycles
Engine
Pwa PW4090
Engine time
14,316 hours, 9,152 cycles
Part
Sensor
Condition
Unknown
Location
Apu
Stage of operation
CR
How discovered
O
Nature of condition
H
Precautionary procedure
J, A

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

What was found

FLIGHT LOST APU. *S/D* LT IDG WAS INOPED 09SEP05. THE RT IDG WAS INOPED, REPLACED. ON 10SEP05 THE APUC GAVE THE MSG COMPLETE LOSS OF APUC BUS ACTIVITY (BOTH LT AND RT 629) FOR 3 SECONDS AFTER THE APU MASTER CONTROL SWITCH HAS BEEN IN THE ON POSITION FOR TEN SECONDS. STATUS MSG-4911110 INACTV ER MODE IAW FIM 49-53 TASK 804 THE APUC CB WAS RESET THE DELTA-P SENSOR WAS CHECKED AND THE APU OPS CHECKED OK.