# SDR UPS04842378

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 14, 2004
- Submitted: May 17, 2004
- Operation: Air carrier
- Aircraft: [N812UP](https://openairdocs.org/aircraft/N812UP), registered now
- Make and model: Doug DC-8-73F
- Registry model: [Doug DC-8-73F](https://openairdocs.org/model/douglas-dc-8-73f) (OpenAirDocs)
- Aircraft serial: 46112
- System (JASC): [2420 · AC Generation System](https://openairdocs.org/jasc/2420)
- Part: Control Panel
- Condition: Failed
- Location: Nr 4
- Stage of operation: TX
- How discovered: O
- Nature of condition: B
- Precautionary procedure: D
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UPS04842378

## Discrepancy

N/A DURING TAXI OUR AND JUST BEFORE TAKEOFF, WE GOT A BUSS POWER FAIL LIGHT AND NR 4 GEN UNPARRALLED LIGHT ON. SMOKE BEGAN TO ACCUMULATE IN THE COCKPIT. TAXIED BACK TO RAMP. FOUND NR 4 GCP TO HAVE A HARD FAILURE.  SUSPECT NR 4 GCP AS CAUSE OF SMOKE. RAN A/C PNEUMATIC SYSTEM, CHECKS NORMAL. REMOVED AND REPLACED NR 4 GCP IAW MM 24-20-0 6-2.  PERFORMED OPERATIONAL CHECK IAW MM 24-20-00-0, OPS CHECKS GOOD.

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