# SDR TAMF20250523051

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 20, 2025
- Submitted: May 23, 2025
- Operation: Air carrier
- Aircraft: [N336QT](https://openairdocs.org/aircraft/N336QT), registered now
- Make and model: Airbus A330-243F
- Registry model: [Airbus A330-243F](https://openairdocs.org/model/airbus-a330-243f) (OpenAirDocs)
- Aircraft serial: 1506
- Aircraft time: 38,038 hours, 10,975 cycles
- Engine: Rroyce RB211TRENT77
- Engine time: 3,650 hours, 11,064 cycles
- System (JASC): [2611 · Smoke Detection](https://openairdocs.org/jasc/2611)
- Part: Smoke Detector
- Part number: PMC310101
- Part serial: 50636
- Condition: Faulted
- Location: Zone 200
- Part time: 43,672 hours
- 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/TAMF20250523051

## Discrepancy

DURING THE CRUISE PHASE, AIRCRAFT N336QT DISPLAYED THE WARNING MESSAGE "CAB PR EXCESS CAB ALT," ACCOMPANIED BY A LOSS OF CABIN PRESSURIZATION. IN RESPONSE TO THIS SITUATION, THE CREW DECIDED TO RETURN TO THE DEPARTURE STATION, MIA. DURING THE FAULT ISOLATION PROCEDURE, THE AIRCRAFT’S SELF-DIAGNOSTIC SYSTEMS WERE INTERROGATED, AND IT WAS DETERMINED THAT THE PACKS HAD BEEN TURNED OFF DUE TO A FAULT CAUSED BY THE SMOKE DETECTOR (120WU), WHICH WAS SUBSEQUENTLY REPLACED.  SMOKE DETECTOR ON/OFF

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.