# SDR FDEA202512250013

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 25, 2025
- Submitted: January 9, 2026
- Operation: Air carrier
- Aircraft: [N883FD](https://openairdocs.org/aircraft/N883FD), registered now
- Make and model: Boeing 777FHT
- Registry model: [Boeing 777FHT](https://openairdocs.org/model/boeing-777fht) (OpenAirDocs)
- Aircraft serial: 39285
- Aircraft time: 58,520 hours, 9,383 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Modulating Valve
- Part number: 329074411
- Part serial: 2390
- Condition: Inoperative
- Location: Left Engine
- Part time: 54,028 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/FDEA202512250013

## Discrepancy

AT FL390 WITH OAT -58C, BEGAN TO RECEIVE  INTERMITTENT PACK L EICAS MESSAGE WITH  CORRESPONDING CABIN TEMPERATURE DROP.  COCKPIT  TEMPERATURE WAS SET TO 26C AS COCKPIT TEMPERATURE  DROPPED TO 10C.  DECENDED TO FL350 AND RAN CABIN  TEMP COLD QRH CHECKLIST THAT DROVE US TO L-PACK OFF  IN ORDER TO SUCCESSFULLY HEAT THE COCKPIT.  FIM 21-61-00-2-0  FAULT FOUND TO BE INTERMITTENT. SWITCH CYCLED FOR  PRECAUTIONARY REF FIM 21-61-00-2-0.  AMM: 36-11-16-4-4, AMM: 36-10-00-5, INSTALLED LT ENG FAMV IAW MM 36-11-16-4-4.  OPS CHECKED NORMAL IAW MM 36-10-00-5. ACP ENG SIM RUN STEP 4. ACFT OK FOR SERVICE.

---
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.