# SDR CALA2026061117038

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 9, 2026
- Submitted: June 11, 2026
- Operation: Air carrier
- Aircraft: [N27421](https://openairdocs.org/aircraft/N27421), registered now
- Make and model: Boeing 737924ER
- Aircraft serial: 37094
- Aircraft time: 56,320 hours, 20,052 cycles
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Check Valve
- Part number: 69291424
- Condition: Damaged
- Location: Zone 100
- Stage of operation: CL
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026061117038

## Discrepancy

ON CLB A/C WOULDNT PRESS  TRIED TO RESET TO MAN  AND ALT NO FIX DID NOTEOUTFLOW WAS SHOWING CL GROUND AIR CONNECTION CHECK VALVE BROKEN.  REMOVED GROUND CONDITIONED AIR CHECK VALVE IAW AMM 21-21-01. INSTALLED GROUND CONDITIONED AIR CHECK VALVE IAW AMM 21-21-01. OPS CHECK AND LEAK CHECK GOOD, PERFORMED CABIN PRESSURE LEAK TEST IAW AMM 05-51-91-790-801. PLANE HOLD PRESSURE GOOD AT THIS TIME.

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