# SDR CALA2025120211691

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 28, 2025
- Submitted: December 2, 2025
- Operation: Air carrier
- Aircraft: [N69020](https://openairdocs.org/aircraft/N69020), registered now
- Make and model: Boeing 777224
- Aircraft serial: 31687
- Aircraft time: 84,368 hours, 8,282 cycles
- System (JASC): [2421 · AC Generator-Alternator](https://openairdocs.org/jasc/2421)
- Part: Idg
- Part number: 756603C
- Part serial: 0075
- Condition: Faulted
- Location: Zone 100
- Part time: 29,953 hours, 3,925 cycles
- Stage of operation: CR
- 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/CALA2025120211691

## Discrepancy

ELEC GEN OFF RT EICAS ADVISORY RT GENERATOR CONTROL BREAKER (GCB) OPEN OR GENERATOR CONTROL SWITCH OFF, & ENG NOT SHUTDOWN.   RT GCU REPLACED ON 11/26 & RT IDG REPLACED ON 11/27 IAW PILOTS ENG 2 IDG TRIPPED AT GATE IN IAD. RESET IAW MANUAL & CONTINUED UNTIL RT IDG TRIPPED & AC DIVERTED. AC HAS KNOWN HISTORY.  IDG OILS READING NORMAL ON INBOUND.  DUE TO RECENT REPETITIVE HISTORY OF ELEC GEN OFF RT BEING REPORTED WITH ONLY MMSG 24-31762 BEING REPORTED ON DIVERSION INTO SFO.   REPLACED RT GENERATOR CONTROL UNIT IAW AMM 24-22-02-400-801 A-E. SOFTWARE CHECK AND TEST NOT ACCOMPLISHED. REPLACED RT GCB.  ACCOMPLISHED ENG RUN FOR NR 2 ENG GCU & CONTACTOR REPLACEMENT. GCU REPLACEMENT IAW 24-22-02-400-801.  RAN ENGINE FOR 10 MIN WITH A LOAD BETWEEN 70-80% AND CYCLED BETWEEN GEN POWER WITH NO ISSUES.

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