# SDR CALA2026030514365

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 2, 2026
- Submitted: March 5, 2026
- Operation: Air carrier
- Aircraft: [N24706](https://openairdocs.org/aircraft/N24706), registered now
- Make and model: Boeing 737724
- Aircraft serial: 28767
- Aircraft time: 85,118 hours, 31,379 cycles
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Valve
- Part number: 40631997201AB
- Part serial: 9719704
- Condition: Faulted
- Location: Cabin Pressure
- Part time: 18,328 hours, 7,714 cycles
- Stage of operation: CR
- 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/CALA2026030514365

## Discrepancy

CABIN DIFFERENTIAL PRESSURE EXCEEDED.   RECOMMENDED VALUES FOR ALTITUDES PER FM1.30.3,  FELT ABNORMAL PRESSURE IN CLIMB & DECENT, BOTH PRESSURIZATION CONTROLLERS BITE TEST PASSED IAW AMM 21-31-00.  NO FAULTS LATCHED.  CREW VERBAL, PRESSURE CHANGE WAS NOTICEABLE. FLIGHT ORIGINALLY PLANNED FO FL 40000 BUT STOPPED CLIMB AT FL 30000 DUE TO DELTA P AT 8.4 PSI.  PACK PRESSURE SPLIT WAS NEGLIGABLE. OUTFLOW VALVE WAS CLEAR. CREW DID NOT SELECT ALTERNATE OR MANUAL. CABIN RATE OF CLIMB WAS NORMAL. REF FIM 21-31 TASK 815 FAULT 30 WAS NOT FOUND ON EITHER DCPC 1 OR 2 SO DUE TO THIS ENGINE BLEED AIR SYS HEALTH CHECK MUST BE PERFORMED AND AIR CONDITIONING PACK AIR FLOW AND THE FUSELAGE LEAKAGE RATE AIRPLANE PACK OPERATION - CONFIDENCE CHECK CONTINUED WITH FIM 21-31 TASK 815 AT STEP F.2.A.  PERFORMED ENGINE BLEED AIR SYSTEM HEALTH CHECKS FOR ENGINE 1 AND 2 REF AMM 36-11-00-700-801. FOUND NO ISSUES, LEAKS, OR ABNORMALITIES WITH EITHER ENGINE.  CONTINUE WITH FIM 21-31 TASK 815 AT STEP F.2.B.-PERFORM THE FUSELAGE LEAKAGE RATE CHECK/ AIRPLANE PACK OPERATION CONFIDENCE CHECK, REF AMM 21-00-05-780-801 COMPLETED FIM TASK 21-31 TASK 815 STEP F (2) B & C. ALL CHECKS GOOD, NO DEFECTS NOTED. ADD EMP:U094459 REF LOG PG. 8095713. OUTFLOW VALVE REPLACED.

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