# SDR P5CA2026012000013

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 21, 2026
- Submitted: January 22, 2026
- Operation: Air carrier
- Aircraft: [N855GT](https://openairdocs.org/aircraft/N855GT), registered now
- Make and model: Boeing 747-87UF
- Registry model: [Boeing 747-87UF](https://openairdocs.org/model/boeing-747-87uf) (OpenAirDocs)
- Aircraft serial: 37567
- Aircraft time: 53,396 hours, 8,529 cycles
- System (JASC): [3350 · Emergency Lighting](https://openairdocs.org/jasc/3350)
- Part: Battery Pack
- Part number: 20131A
- Part serial: 116682
- Condition: No Test
- Location: Zone 200
- Stage of operation: IN
- How discovered: C
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/P5CA2026012000013

## Discrepancy

FOUND EXTERIOR EMER LT (L6690) INOP.  PERFORM WIRING CONTINUITY CHECK AND SYSTEM TROUBLESHOOTING IAW WDM 33-51-72 REV 35, FOUND M5168 BATTERY FUNCTION FAILED.  PERFORM BATTERY REPLACEMENT AT M5168 IAW AMM 33-51-04-900-803 REV 49. CONDITION CHECK NORMAL AND PERFORM POWER SUPPLY TEST, RESULT WAS SATISFACTORY.

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