# SDR CALA2026031814658

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 16, 2026
- Submitted: March 18, 2026
- Operation: Air carrier
- Aircraft: [N77867](https://openairdocs.org/aircraft/N77867), registered now
- Make and model: Boeing 757-33N
- Registry model: [Boeing 757-33N](https://openairdocs.org/model/boeing-757-33n) (OpenAirDocs)
- Aircraft serial: 32592
- Aircraft time: 71,548 hours, 21,250 cycles
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Clamp
- Condition: Missing
- Location: Check Valve
- Stage of operation: CR
- How discovered: O
- Nature of condition: W
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026031814658

## Discrepancy

LEFT PACK UNABLE TO MAINTAIN CABIN ALTITUDE BELOW 10000FT AT FL330 LOCKED DUE TO CREW DECLARED EMERGENCY.  DURING PRESSURIZATION CHECKS NOTICED THAT THE CABIN AIR SUPPLY CHECK VALVE AFT BOOT HAD MISSING BAND CLAMP. INSTALLED NEW BAND CLAMP AND PERFORMED LEAK CHECKS. NO LEAKS FOUND. REF AMM 21-51-15-404-011. PERFORMED EXCESSIVE CABIN PRESSURE LEAKAGE TEST WITH LH PACK REFERENCING AMM 05-51-24-702-001. ABLE TO MAINTAIN CABIN PRESSURE FOR SEVERAL MINUTES.

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