# SDR CALA2026052016411

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 19, 2026
- Submitted: May 20, 2026
- Operation: Air carrier
- Aircraft: [N24973](https://openairdocs.org/aircraft/N24973), registered now
- Make and model: Boeing 787-9
- Registry model: [Boeing 787-9](https://openairdocs.org/model/boeing-787-9) (OpenAirDocs)
- Aircraft serial: 40941
- Aircraft time: 39,797 hours, 3,761 cycles
- System (JASC): [3350 · Emergency Lighting](https://openairdocs.org/jasc/3350)
- Part: Control Unit
- Part number: 100260103
- Condition: Failed
- 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/CALA2026052016411

## Discrepancy

EMERGENCY LIGHTS AT DOOR 4R DOES NOT LIGHT UP DURING OPS CHECK. MAINT MSG:33-11208 & 33-11408 REPLACEMENT OF WCU & WBU CLASS 8 AT DOOR 4R C/OUT IAW AMM 33-51-07-01A-520/720A-A & 33-51-07-02B/720A-A. TEST SATIS.   REPLACEMENT OF WCU & WBU CLASS B AT DOOR 4R C/OUT IAW AMM 33-51-07-01A-520/720A-A & 33-51-07-02B-520/720A-A. TEST SATISFACTORY.  REPLACEMENT OF WCU & WBU CLASS 8 AT DOOR  4R  C/OUT IAW AMMM 33-51-07-01A-520/720A-A & 33-51-07-02B/720A-A. TEST SATISFACTORY.

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