# SDR ASAA2018110526719

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 5, 2018
- Submitted: November 6, 2018
- Operation: Air carrier
- Aircraft: [N440AS](https://openairdocs.org/aircraft/N440AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41705
- Aircraft time: 20,223 hours, 6,699 cycles
- System (JASC): [4990 · APU Oil System](https://openairdocs.org/jasc/4990)
- Part: Indicator
- Part number: 38810521
- Condition: Missing
- Location: Pressure Switch
- Stage of operation: IN
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2018110526719

## Discrepancy

APU HAS A HISTORY OF OIL SERVICING CURRENT OIL CONSUMPTION IS HIGHER THAN EXPECTED. GROUNDED - YES. UPON OPENING OF APU COWLING FOUND OIL LEAKING FROM THE DIFFERENTIAL PRESSURE INDICATOR, DELTA P INDICATOR WAS MISSING, WHICH CAUSE THE HIGH APU OIL CONSUMPTION. REMOVED AND REPLACED DIFFERENTIAL PRESSURE INDICATOR REF B737-900 AMM 49-91-13.

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