Service difficulty report · Solenoid · Boeing 747422

Difficulty date
September 21, 2005
Submitted
September 27, 2005
Operation
Air carrier
Aircraft
N128UA
Make and model
Boeing 747422
Aircraft serial
30023
Aircraft time
21,134 hours, 2,711 cycles
Engine
Pwa PW4056
Part
Solenoid
Condition
Burned
Location
Cabin
Stage of operation
NR
How discovered
O
Nature of condition
B
Precautionary procedure
A

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

What was found

RUBBER BURNING SMELL IN CABIN/FLIGHT DECK. SMOKE IN FLIGHT DECK RESULT OF STRIKE SOLENOID OVERHEATING. DOOR MAY HAVE BEEN SLIGHTLY SPRUNG OR "PRELOADED" IN THE FULLY CLOSED POSITION WHICH CAUSED THE STRIKE SOLENOID TO BIND AND PREVENT FULL EXTENSION OF THE LOCK PIN. THIS IN TURN CAUSED IN THE SOLENOID TO CONTINUALLY DRIVE AND OVERHEAT. THIS SOLENOID HAS BEEN REVISED BY THE MANUFACTURER TO INCORPORATE THERMAL PROTECTION. NEW SOLENOIDS ARE REQUIRED TO BE INSTALLED EVERY 4 YEARS PER EC 82-5251-002AD-A. NEW STRIKE SOLENOIDS WILL SUPERSEDE OLD STRIKE SOLENOIDS IN THE UAL SYSTEM VIA SCR.