# SDR 99ZZZM774

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 21, 1999
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N623FF
- Make and model: Boeing 747-2F6B
- Registry model: [Boeing 747-2F6B](https://openairdocs.org/model/boeing-747-2f6b) (OpenAirDocs)
- Aircraft serial: 22382
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: Relief Vlv
- Part number: A111857
- Condition: Inoperative
- Location: Nr 4 Engine
- Stage of operation: TO
- Nature of condition: M, J
- Precautionary procedure: C, D
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99ZZZM774

## Discrepancy

DURING TAKEOFF AT 142 KNOTS AND PRIOR TO V1 NR 4 ENGNE FIRE WARNING LIGHT AND BELL CAME ON CAPTAIN ABORTED TAKEOFF AND BOTH BELL AND LIGHT WENT OUT AS CAPTAIN INDICATED THE ABORT.  REMOVED AND REPLACED NR 4 OVER PRESSURE VALVE AND NR 4 ENGINE BLEED REGULATOR VALVE.  PERFORMED R/U PER MM 71-00-00, TEST 4 ALL,  LEAKS CHECKED OK.  (M)

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