Liberty Aviation Charter LLC.

Sanction: $21,000 · case closed 2025-08-15

Part: THROTTLE — DIRTY (COCKPIT) · airframe 6,479 hrs · 5,502 cycles

DURING CRUISE FLIGHT LEFT ENGINE THROTTLE STUCK AT 95% N2 WITH NO ABILITY TO ADJUST. LEFT ENGINE THROTTLE CUTOFF ALSO LOCKED IN ON POSITION. PILOTS WERE ABLE TO FREE THE ENGINE CONTROL AND MANIPULATE POWER AS REQUIRED. UPON INSPECTION OF THE AIRCRAFT AT KMDT IT WAS NOTED THAT THE LEFT ENGINE THROTTLE CONTROL WAS NOTCHY/STIFF. WE WERE ABLE TO CLEAN THE FRICTION CONTROL SUBASSEMBLY AND THE LEFT THROTTLE RETURNED TO SMOOTH OPERATION.

Part: FLOW VALVE — LEAKING (RIGHT)

WHILE IN CRUISE FLIGHT AT 33,000, THE CABIN ALTITUDE ABOVE 10,000 FEET WARNING LIGHT ILLUMINATED WITH ASSOCIATED MASTER WARNING LIGHT ILLUMINATION. PRESSURIZATION CONTROLLER GAUGE WAS RISING ABOVE 14000 FEET AND PEAKED AT 15,000 FEET. (INITIAL CRUISE ALTITUDE WAS PREVIOUSLY 41000 FEET). NO RAPID DEPRESSURIZATION OCCURRED. COMPLETED THE ABNORMAL CHECKLIST. THE CABIN MASK DROPPED, AND PILOTS AND PASSENGERS DONNED THEIR MASK. DESCENDED AIRCRAFT TO 10,000 FEET. CABIN CONTROLLER DESCENDED THE CABIN TO APPROXIMATELY 7000 FEET INITIALLY WITH AIRCRAFT AT 10000 FEET. FURTHER NORMAL ATC DESCENTS WERE COMPLETED ENROUTE. AIRCRAFT WAS DEPRESSURIZED NORMALLY AND CABIN DOOR OPENED NORMALLY WITHOUT ANY RESIDUAL PRESSURIZATION. FOLLOWING MAINTENANCE TROUBLESHOOTING, THE FLOW CONTROL VALVE WAS DEFERRED IN ACCORDANCE WITH MEL 21-1 AS THE PRESSURIZATION PREFLIGHT SHOWED NO CHANGE IN THE CABIN DIFFERENTIAL PRESSURE GAUGE. THE AIRCRAFT WAS REPOSITIONED TO MAINTENANCE BASE UNPRESSURIZED FOR REPAIRS.

Part: UNKNOWN — UNKNOWN (UNKNOWN) · airframe 7,679 hrs · 5,557 cycles

LEFT AND RIGHT BLEED OVERHEAT LIGHT ILLUMINATED DURING CRUISE. TROUBLESHOT LIGHTS AND FOUND EMERGENCY BLEED VALVE CLAMPS LEAKING. REMOVED CLAMPS, INSPECTED AND REINSTALLED CLAMPS. LEAK CHECK GOOD.

Part: REGULATOR VALVE — FAILED (CABIN PRESSURE) · airframe 7,244 hrs · 5,193 cycles

THE AIRPLANE TOOK OFF FROM KACG AND THE CABIN HEAT WAS NOT ABLE TO BE REGULATED. THE CABIN TEMPERATURE CONTINUED CLIMBED SO THEY HAD TO GO BACK TO KACG. THERE WASN'T PRESSURIZATION PROBLEMS. THE PILOTS HAD TO BURN OFF FUEL AND FLEW FOR APPROXIMATELY 45 MINUTES. THEY WERE ABLE TO GET THE TEMPERATURE DECREASE WHEN THE LEFT BLEED AIR WAS TURNED OFF. AFTER TROUBLESHOOTING WE FOUND THAT THE EMERGENCY PRESSURIZATION VALVE WAS STUCK IN EMERGENCY. THIS MADE THE BLEED AIR TEMPERATURE TO BE UNREGULATED COMING INTO THE CABIN.

Part: CONNECTING ROD — FAILED (NR 5 CYLINDER)

AIRCRAFT WAS CLIMBING AFTER TAKEOFF, LOUD NOISE HEARD BY PILOT, OIL PRESSURE STARTED TO DROP, ENGINE FEATHERED. AIRCRAFT LANDED WITHOUT INCIDENT. FOUND NR 5 CYLINDER CONNECTING ROD FAILED, KNOCKED HOLE IN UPPER CRANKCASE. ENGINE TOTAL TIME 2,768.7 HOURS, 1,215.7 HOURS SMOH. (X)