# SDR ASAA2017081021612

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 10, 2017
- Submitted: August 14, 2017
- Operation: Air carrier
- Aircraft: [N453AS](https://openairdocs.org/aircraft/N453AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 36354
- Aircraft time: 14,178 hours, 4,664 cycles
- System (JASC): [2612 · Fire Detection](https://openairdocs.org/jasc/2612)
- Part: Fire Detector
- Part number: 90202001
- Condition: Failed
- Location: Apu Bay
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2017081021612

## Discrepancy

APU DETECTOR INOPERATIVE, ILLUMINATED IN CRUISE AT 3500' WITH THE APU NOT RUNNING SAT -48 DEG. CEL.  ACFT GROUNDED.  IAW WDM 26-11-31,  AMM 26-15-01-000-802. ACCOMPLISHED ALT DEACTIVATION REF CH 5 TABLE 3 ITEM 1. ACCOMPLISHED RESISTANCE CHECKS OF APU FIRE DETECTORS. DETECTORS M1755, M1756 ARE WITHIN LIMITS. DETECTOR M1925 IS OUT OF LIMITS. REMOVED AND REPLACED M1925 DETECTOR.

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