Service difficulty report · Smoke Detector · Boeing 777222

Difficulty date
March 8, 2026
Submitted
March 10, 2026
Operation
Air carrier
Aircraft
N229UA
Make and model
Boeing 777222
Aircraft serial
30557
Aircraft time
94,758 hours, 11,079 cycles
Part
Smoke Detector
Part number
PU90471WR1
Condition
False Activation
Location
Zone 900
Stage of operation
CR
How discovered
O
Nature of condition
N
Precautionary procedure
A

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

What was found

THE TOMC CONTROLLER AND SENIOR MANAGER CONCUR THAT THE AIRCRAFT CAN BE RELEASED BACK TO SERVICE AFTER EXPERIENCING A DIVERSION OR AIR TURN BACK DUE TO A MECHANICAL REASON LOCKED BY SYSTEM. UNLOCKING TOMC GG AND SR MGR BK CONCUR ON FIX REF LP 8141323 REPLACED SMOKE DETECTOR AT LAV 4L ACCOMPLISHED GROUND TEST OPS CK GOOD NO FAULT FOUND.LAV DOOR 4L SMOKE DET SOUNDS INTERMITTLY PER DEBRIEF WITH FLIGHT CREW, 40 MINUTES INTO FLIGHT SMOKE DETECTOR WAS INTERMITTENT DURING FLIGHT. THEY STATED THAT IT TURNED OFF ON THE RETURN. UPON MAINTENANCE ARRIVAL TO AIRCRAFT, FOUND DECTECTOR INSTALLED TO BE FAULTY. REPLACED SMOKED DETECTOR ADD EMP:U123554 AT LAV 4L REF AMM TASKS 26-13-01-000-803 AND 26-13-01-400-802. PERFORMED ALL TEST ON CSCP REF TASK 26-13-00-710-801, NO FAULTS NOTED FOR LAV SMOKE DETECTOR. OKAY TO CONTINUE.