# SDR 2026FA0000586

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 11, 2026
- Submitted: July 16, 2026
- Operation: General aviation
- Aircraft: [N924PS](https://openairdocs.org/aircraft/N924PS), registered now
- Make and model: Lear 60LEAR
- Aircraft serial: 60050
- Aircraft time: 15,074 hours, 9,827 cycles
- Engine: Pwa PW305A
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Mixing Valve
- Part number: 1H1069
- Part serial: 6BA14
- Condition: Defective
- Location: Engine
- Stage of operation: CL
- How discovered: O
- Nature of condition: M, J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2026FA0000586

## Discrepancy

AIRCRAFT DEPARTED KTIX EMPTY HEADING TO KOPF. ON TAKEOFF/CLIMB, CAPTAIN NOTICED CABIN AIR SWITCH WAS OFF, CAPTAIN THEN TURNED IT ON. A FEW MOMENTS LATER CREW WERE GETTING HOT AIR & SMOKY RESIDUE IN COCKPIT AREA. THEY ELECTED TO RETURN TO KTIX, DECLARE AN EMERGENCY. LANDED SAFELY BACK AT TIX. MAINT INSPECTED ACFT & DID NOT SEE ANY OBVIOUS ISSUES WITH PRESSURIZATION SYS.  NEXT MORNING MAINT RAN ENGS & ABLE TO DUPLICATE HOT AIR IN CABIN/COCKPIT AREA. COMPLETING  TROUBLESHOOTING PROCEDURES IAW MM, LT ENG BLEED AIR MIXING VALVE WAS FOUND TO BE DEFECTIVE & REPLACED. EMERGENCY PRESSURIZATION VALVES REPLACED FOR PRECAUTIONARY PURPOSES. ENGS WERE RUN UP & FUNCTIONAL CHKS COMPLETED, NO DISCREPANCIES NOTED. A TEST FLT WILL BE COMPLETED BEFORE IT IS RETURNED TO SERVICE.

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