# SDR 9806976718

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 19, 1998
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N618US](https://openairdocs.org/aircraft/N618US), registered now
- Make and model: Boeing 747251F
- Aircraft serial: 21122
- Engine: Pwa JT9D7F
- System (JASC): [7714 · Engine RPM Indicating System](https://openairdocs.org/jasc/7714)
- Part: Tachometer
- Condition: Malfunctioned
- Location: Nr 4 Engine
- Stage of operation: TO
- Nature of condition: O
- Precautionary procedure: C, D
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/9806976718

## Discrepancy

DURING TAKEOFF ROLL AT APPROXIMATELY 115 KTS, THE NR 4 ENGINE N1 RPM INDICATION MALFUNCTIONED.  THE TAKEOFF WAS ABORTED.  MAINTENANCE PLACED THE NR 4 ENGINE N1 INDICATION SYSTEM ON MEL AND THE AIRCRAFT RETURNED TO SERVICE.

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