Service difficulty report · Smoke Detector · Boeing 747422

Difficulty date
February 27, 2010
Submitted
March 5, 2010
Operation
Air carrier
Aircraft
N128UA
Make and model
Boeing 747422
Aircraft serial
30023
Aircraft time
39,994 hours, 4,804 cycles
Engine
Pwa PW4056
Part
Smoke Detector
Part number
2156756A
Condition
Shorted
Location
Cabin
Stage of operation
IN
How discovered
V
Nature of condition
O
Precautionary procedure
K

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

What was found

SHORTLY AFTER T-O, CAUTION MSG SMOKE DOOR 5 REST. CREW REST AREA, SMOKE DETECTOR HORN SOUNDED. FLT CREW SILENCE HORN AND RESET FAN ON TEMP CONTROL MODULE BY STAIRWAY, NO HELP. FOUND CREW REST AREA NOTIFICATION SIGNS SLIGHTLY DISCOLORED FROM BULBS, REMOVED BULBS PRECAUTIONARY. PULLED CB AT P6 PANEL, G34 FOR COMPARTMENT TEMP SENSOR. LAV-GALLEY VENT FANS TRIPPED CAUSING ALL CHILLERS TO GO INOP. FOUND ZONE 2 DETECTOR NR 1 SHORTED. REPLACED AND OPS CHECKED ALL RECIRCULATION FANS AND DETECTORS. NO FAULTS FOUND.