# SDR CALA2026043015903

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 30, 2026
- Submitted: April 30, 2026
- Operation: Air carrier
- Aircraft: [N65832](https://openairdocs.org/aircraft/N65832), registered now
- Make and model: Boeing 737924ER
- Aircraft serial: 44563
- Aircraft time: 37,425 hours, 13,762 cycles
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Indicator
- Part number: 171370000
- Part serial: 5689
- Condition: Faulty
- Location: Cabin Pressure
- Part time: 37,425 hours, 13,762 cycles
- Stage of operation: CL
- How discovered: O
- Nature of condition: S
- Precautionary procedure: B, A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026043015903

## Discrepancy

AUTO FAIL PRESSURIZATION UNCONTROLABLE ABOVE FL250TOMC REQUEST.  PERFORMED FIM 21-31 TASK 801, NO FINDINGS. ALL CHECKS GOOD. STATUS INDICATIONS ARE AS EXPECTED. AUTOFAIL LIGHT IS OFF. PERFORMED 1 AND 2 PRESSURE CONTROLLERS GROUND TEST, REF AMM TASK 21-31-00-700-802, BITE TESTS CHECK GOOD. PERFORMED MASTER CAUTION TEST, REF AMM TASK 21-31-00-700-801, OPS CHECKS GOOD. PERFORMED FLT ALT AND LAND ALT DISPLAY TEST, IAW AMM 21-31-00-700-803, LAND ALT DISPLAY WINDOW - ONE DIGIT NOT DISPLAYED CLEARLY (SEE PICTURE). REPLACING CABIN PRESSURRE CONTROL MODULE RECOMMENDED. PERFORMED CABIN PRESSURIZATION LEAK TEST, IAW AMM 05-51-91-790-801. LEAK DECAY CHECK WITHIN LIMITS, ELAPSED TIME FROM 4.0PSID - 2.5PSID WAS 156 SECONDS. NOTED DUAL ALTIMETER AND DIFFERENTIAL PRESSURE INDICATOR ASSY SHOWING INACCURATE INDICATION ON THE CABIN ALTITUDE NEEDLE (TURNING COUNTERCLOCKWISE). REPLACING THE INDICATOR ASSY IS RECOMMENDED.  CABIN ALTITUDE AND DIFFERENTIAL PRESSURE INDICATOR REPLACED AND OPS CKD OK. SELECTED SDR REF LP 8726909 FOR CABIN PRESSURE CONTROL PANEL WORK PERFORMED AND REPLACEMENT REF LP 8726909 FOR CABIN PRESSURE CONTROL PANEL. ALL WORK COMPLETED AND COMPLIED WITH.

---
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.