What was found
CABIN ALT WARNING IN CRUISE. UNCONTROLLABLE IN AUTO OR STANDBY. WAS CONTROLLABLE IN MANUAL MODE. CR FLT 320 FOR ABOUT 30 MINS. REMOVED AND REPLACED CABIN PRESS OUTFLOW VALVE, OPS CHECK GOOD REF B737-400 AMM 21-31-11
- Difficulty date
- June 22, 2026
- Submitted
- June 25, 2026
- Operation
- Air carrier
- Aircraft
- N409YK
- Make and model
- Boeing 737436
- Aircraft serial
- 25859
- Aircraft time
- 61,843 hours, 43,003 cycles
- System (JASC)
- 2133 · Pressure Regulator/Outflow Valve
- Part
- Outflow Valve
- Part number
- 7110035
- Part serial
- 95110026
- Condition
- Failed
- Location
- Zone 100
- Part time
- 31,523 hours, 23,031 cycles
- Stage of operation
- CR
- How discovered
- O
- Nature of condition
- J
- Precautionary procedure
- A
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.