SPEEDJETS, LLC

ACFT DEPARTED. NO ISSUES DURING CLIMB. WHILE PASSING THRU FL 240, IT WAS OBSERVED THE ACFT HAD EXCESSIVE NOSE UP TRIM. AUTOPILOT ENGAGED AT THE TIME. THE ACFT, ASIDE FROM TRIM, FLEW NORMALLY. LEVELED OFF AT FL 410. AT CRUISE, AUTOPILOT HELD ACFT LEVEL, BUT TRIM WAS STILL FULL NOSE UP. DURING DESCENT, THE AUTOPILOT DESCENDED THE ACFT, BUT TRIM WENT FULL NOSE DOWN. THE PILOT PULLED BACK ON YOKE SO THE ACFT WOULDN'T NOSE OVER. THE PILOT STATED AT THIS TIME THE FGC COMPUTERS FAILED. CREW WENT TO MANUAL & HAD DIFFICULTY FLYING THE AIRCRAFT WITH FULL AFT TRIM. FULLY CONFIGURED THE TRIM WAS FULL NOSE UP. THE PILOT STATES HAD TO PUT AN EXTREME AMOUNT OF FORCE TO PREVENT THE AIRCRAFT FROM NOSING OVER. MX WAS NOTIFIED AND FOUND THAT FASTENERS SHEARED ON THE LOWER PORTION OF THE TRIM DRIVE SHAFT ASSEMBLY TORQUE TUBE PART NUMBER 43083-818 LOCATED IN THE COCKPIT PEDESTAL.

LEFT FUEL LOW PRESSURE LIGHT CAME ON. CREW CARRIED OUT CHECKLIST, RT LOW FUEL PRESSURE LIGHT LIGHT ON WHEN CROSSFEED VALVE OPENED. IMBALANCE OF FUEL WAS NOTED, AUX FUEL WOULD NOT TRANSFER CROSSFEED VALVE CLOSED, BOTH FUEL LOW PRESSURE LIGHTS EXTINGUISHED. THEN LT FUEL LOW PRESSURE CAME BACK. AIRCRAFT DIVERTED. MAINTENANCE POINTED TO INTERMITTENT AND/OR DEFECTIVE VENTRAL TANK REFUEL/DEFUEL VALVE.

ON 12-31-2016 AT APPROXIMATELY 10:00 CST, PIC OBSERVED A LOW PRESSURE FUEL LIGHT AND A NOTICEABLY INCREASING FUEL IMBALANCE. DECLARED AN EMERGENCY AND LANDED, DOUR TROUBLESHOOTING, FOUND DEBRIS IN THE CONNECTOR PLUG TO THE LOW PRESSURE SWITCH. THE DEBRIS WAS CLEANED AND CONNECTOR INSTALLED. THE FUEL TRANSFER, CROSSFEED VALVE AND FOUND IT WET WITH WATER. CLEANED AND COVERED VALVE IN GREASE IAW AMM 28-20-00. PERFORMED MULTIPLE ENGINE RUNS IAW MM 71-00-00 AT DIFFERENT POWER SETTINGS AND PERFORMED MULTIPLE FUEL TRANSFERS WITH NO DEFECTS NOTED. AN OPERATIONAL FLIGHT CHECK WAS SATISFACTORILY PERFORMED WITH NO DEFECTS NOTED. AIRCRAFT WAS RETURNED TO SERVICE.

HYDRAULIC UTILITY PUMP SHUTOFF VALVE SOLENOID WOULD NOT DE-ENERGIZE. BROUGHT AIRCRAFT IN FOR MAINTENANCE. REPLACED UNIT WITH OVERHAULED UNIT P/N 3846 (1159SCH217-5), S/N 638A. UNIT STAYED OPEN AND WOULD POP THE CIRCUIT BREAKER. RETURNED UNIT FOR EXCHANGE.

HYDRAULIC UTILITY PUMP SHOUT OFF VALVE SOLENOID WOULD NOT DE-ENERGIZE THEREBY ALLOWING THE UTILITY PUMP TO RUN CONTINUOUSLY. BROUGHT A/C IN FOR MAINTENANCE AND REPLACED SHUTOFF VALVE SOLENOID WITH OVERHAULED UNIT P/N 3846 (1159SCH217-5, S/N 351A. FOUND UNIT LEAKING, SO REMOVED AND RETURNED TO VENDOR CREDIT.