# SDR DXTA2025050203291

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 30, 2025
- Submitted: May 2, 2025
- Operation: Air carrier
- Aircraft: [N945QS](https://openairdocs.org/aircraft/N945QS), registered now
- Make and model: Cessna 680A
- Registry model: [Cessna 680A](https://openairdocs.org/model/cessna-680a) (OpenAirDocs)
- Aircraft serial: 680A0378
- Aircraft time: 1,504 hours, 1,038 cycles
- System (JASC): [2612 · Fire Detection](https://openairdocs.org/jasc/2612)
- Part: Fire Detector
- Condition: Faulted
- Location: Zone 400
- Stage of operation: CR
- How discovered: O
- Nature of condition: N
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/DXTA2025050203291

## Discrepancy

ON CLIMB OUT BETWEEN 4000 & 15000 FT, MCT THRUST SET & LIGHT TURBULANCE, FIRE DETECT FAIL L AMBER CAS DISPLAYED 5 TIMES. TWO RING TERMINALS ON FIRE DETECT SENSOR AT 6 O'CLOCK POSITION TIGHT WITH NO SIGNS OF WEAR OR MOVEMENT. VISUAL OF THE HARNESS WITH BORESCOPE, NO OBVIOUS DEFECTS. IAW CMM 26-10-01.  REMOVED LT ENG FIRE SENSOR WIRING HARNESS IAW MM 26-10-01. VERIFIED 4 EVENTS OF THIS CAS MESSAGE ON ARES VIEW. MEASURED RESISTANCE OF INTERNAL FIRE LOOP PD031 PINS A & C, MEASURED AT 2.987K OHMS. VERIFIED ANOTHER D1 ENG READING THE SAME RESISTANCE VALUE FOR THE INTERNAL FIRE LOOP.  CONTINUITY CHK FROM PD023 PINS M & N TO PD031 PINS A & C. CHKD GOOD. DONE IAW FAULT ISOLATION 3, FIGURE 114 72-00-02 & MM 26-00-00.

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