# SDR 98ZZZM491

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 15, 1998
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N980VJ
- Make and model: Doug DC-9-31
- Registry model: [Doug DC-9-31](https://openairdocs.org/model/douglas-dc-9-31) (OpenAirDocs)
- Aircraft serial: 48156
- System (JASC): [3416 · Altimeter, Barometric/Encoder](https://openairdocs.org/jasc/3416)
- Part: Altimeter
- Part number: A4086910121
- Condition: Malfunctioned
- Location: Lt Cockpit
- Stage of operation: CR
- Nature of condition: O
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/98ZZZM491

## Discrepancy

DCA-SDF - FL 201, THE CAPTAINS ALTIMETER WAS ERRATIC WITH A 500 FT DROP IN CORRECTED MODE.  THE DIFFERENTIAL DECREASED WITH A DECREASE IN ALTITUDE.  THE AIRCRAFT WAS DIVERTED TO PIT AND LANDED WITHOUT INCIDENT.  MAINTENANCE REPLACED THE MACH AIRSPEED INDICATOR AND A LEAKING STATIC LINE AT THE MACH SPEED INDICATOR.  BOTH ALTIMETERS WERE ALSO REPLACED AS A PRECAUTIONARY MEASURE.  (M)

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