# SDR 9WGA2026052134401

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 21, 2026
- Submitted: May 21, 2026
- Operation: Air carrier
- Aircraft: [N344KD](https://openairdocs.org/aircraft/N344KD), registered now
- Make and model: Boeing 747446
- Aircraft serial: 26344
- Aircraft time: 98,376 hours, 18,668 cycles
- System (JASC): [2450 · AC Power Distribution System](https://openairdocs.org/jasc/2450)
- Part: Buss Protection
- Part number: 746013J
- Part serial: 0536
- Condition: Faulty
- Location: Zone 100
- Stage of operation: CL
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/9WGA2026052134401

## Discrepancy

AFTER TAKE-OFF FROM NRT,  INDICATION, AC BUS 1 FAIL, RETURNED TO NRT, MAINTENANCE PERFORMED PER FIM 24-23 TASK 812, REMOVED AND REPLACED BCU, TESTED EPGS (GCU1) AND EPGS 2 (GCU2) GROUND TEST COMPLIED WITH, TEST PASSED.

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