Service difficulty report · Window · Boeing 777222

Difficulty date
October 30, 2002
Submitted
November 20, 2002
Operation
Air carrier
Aircraft
N772UA
Make and model
Boeing 777222
Aircraft serial
26930
Aircraft time
29,530 hours, 5,884 cycles
Engine
Pwa PW4077
Part
Window
Part number
141W74002
Part serial
98273H8377
Condition
Cracked
Location
Cockpit
Part time
15,047 hours, 5,884 cycles
Stage of operation
CR
How discovered
V
Nature of condition
O
Precautionary procedure
B

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

What was found

1ST OFFICER'S FWD OUTER WINDSHIELD FAILED. PRESSURIZATION MAINTAINED AT ALL TIMES. THE OUTER LAYER OF GLASS SHATTERED DUE TO ARCING AT THE UPPER BUS BAR FOR THE WINDOW HEAT SYSTEM. THE CAUSE OF THE ARCING WAS DUE TO MOISTURE INGRESS INTO THE ELECTRICAL HEAT SYSTEM BUS BAR AT THE AREA WHERE THE HEAT FILM ATTACHES TO THE BUS BAR. CONTRIBUTING FACTORS OF POOR ADHESION OF THE MOISTURE SEAL AND DELAMINATION IN AND AROUND THE UPPER BUS BAR AREA ALLOWED THE WATER TO PENETRATE INTO THE AREA. REMOVED AND REPLACED THE WINDOW ASSY PER AMM 56-11-01-401.