Service difficulty report · Battery Pack · Boeing 74744AF

Difficulty date
October 10, 2026
Submitted
October 12, 2026
Operation
Air carrier
Aircraft
N573UP
Make and model
Boeing 74744AF
Aircraft serial
35662
Aircraft time
65,817 hours, 10,453 cycles
Part
Battery Pack
Part number
20131A
Part serial
56169
Condition
Inoperative
Location
Zone 200
Stage of operation
IN
How discovered
C
Nature of condition
L
Precautionary procedure
K

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

What was found

FOUND UPPER DECK EMERGENCY LIGHT M4915, L1533, L5733,5767 INOPERATIVE. IAW AMM 33-51-04-002-009-001, 33-51-04-402-012-001, AND 33-51-04-902-001-001 REV.117 AND SSM 33-51-01 REV.48 REPLACED THE EMERGENCY LIGHT POWER SUPPLY M5169 AND THE BATTERY ASSEMBLY, AND PERFORMED THE POWER SUPPLY TEST, RESULT WAS SATISFACTORY.

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