# SDR CALA2026051916381

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 15, 2026
- Submitted: May 20, 2026
- Operation: Air carrier
- Aircraft: [N73278](https://openairdocs.org/aircraft/N73278), registered now
- Make and model: Boeing 737824
- Aircraft serial: 31596
- Aircraft time: 65,834 hours, 23,995 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: A/C Pack
- Condition: Faulted
- Location: Right
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026051916381

## Discrepancy

RIGHT PACK HAVING START UP ISSUES REQUESTING MEL 2101B FOR RH PACK IAW MEL 2102B. WILL COMPLY WITH MEL CONDITIONS UPON APPROVAL. DISPATCH DESK.OK TO APPLY MEL 2101B FOR RIGHT PACK INOP COMPLIED WITH MEL REVERSED MEL FOR TROUBLESHOOTING. BITE TEST OF BOTH BOXES SHOWED NO FAULTS. COULD NOT GET PACK TO START. DISCRETES SHOWED SWITCH POSITION CHANGE NORMALLY BUT PACK NEVER CAME ON, DUCT PRESSURE INCREASED TO 50PSI WHEN SWITCH WAS COMMANDED. DUE TO ACM REQUIRING REMOVAL COULD NOT REPLACE FLOW CONTROL VALVE WITH REMAINING GROUND TIME. ALSO COULD NOT VERIFY PACK OPERATION STATUS AT THIS TIME. RESTORED AIRCRAFT TO MEL CONFIGURATION PREFORMED PACK TEMPERATURE CONTROL - BITE PROCEDURE REF FIM 21-62 TASK 801. FOUND NO FAULTS. REACTIVATED RIGHT PACK FOR TROUBLESHOOTING PURPOSES AND OPS CHECKED IT FOUND THAT RIGHT PACK DOES NOT TURN ON RIGHT AWAY, OTHER INSTANCES IT DOES NOT TURN ON AT ALL. SUSPECT THE FLOW CONTROL VALVE INTERMITTENTLY FAULTING. IN THE INSTANCE WHEN THE RIGHT PACK WORKED NO ODOR WAS NOTICED IN THE CABIN. NOT ENOUGH GROUND TIME TO CHANGE THE PART. REF AMM TASK 21-51-01-000-805-002 FOR REPLACEMENT PROCEDURE. REAPPLIED MEL CONFIGURATIONS TO THE RIGHT PACK.

---
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.