N990QS

Part: SHUTOFF VALVE — FAILED (APU) · airframe 15,078 hrs · 9,020 cycles

WHILE STARTING THE APU WHILE AIRBORNE THERE WAS A LOUD BOOM AND SIMULTANEOUSLY THE APU FIRE ANNUNCIATOR ILLUMINATED MOMENTARILY. THE APU WAS SHUT DOWN AND THE APU FAUL ANNUNCIATOR ILLUMINATED. REMOVED AND REPLACED THE FUEL SHUTOFF VALVE SOLENOID AND FUEL FLOW DIVIDER IAW MM 49-30-54 & 49-30-58.

Part: SKIN — CORRODED (FUSELAGE) · airframe 14,904 hrs · 8,916 cycles

FOUND LOWER STINGER SKIN NEAR THE APU CORRODED. REPLACED WITH NEW SKIN P/N 6712615-56.

Part: SKIN — CORRODED (TAILCONE) · airframe 14,904 hrs · 8,916 cycles

FOUND LOWER AFT TAILCONE SKIN AND STRINGER, NEAR THE APU, CORRODED. REPLACED PARTS WITH NEW STRINGER P/N 6712615-56 AND LOWER SKIN P/N 6712615-56.

Part: SKIN — CORRODED (LT WING) · airframe 14,904 hrs · 8,916 cycles

REPLACED CORRODED LH INBOARD UPPER WING SKIN WITH NEW P/N 6722311-17.

Part: DRAG ANGLE — CORRODED (LT WING) · airframe 14,904 hrs · 8,916 cycles

REPAIRED CORROSION FOUND UNDER THE LH WING FORWARD AND AFT DRAG ANGLES PER CESSNA REPAIR DEFINITION S-750-0190/17RD. REPAIRED CORROSION FOUND UNDER THE RH WING AFT DRAG ANGLE PER CESSNA REPAIR DEFINITION S-750-0190/17RD. MECHANICALLY BLENDED APPROXIMATELY 40 AREAS OF CORROSION ON LH UPPER WING SKIN SURFACES. PERFORMED ULTRASONIC THICKNESS AND EDDY CURRENT INSPECTION AND SUBMITTED FINDINGS TO CESSNA FOR REPAIR DISPOSITION. PERFORMED ROTO PEEN, TREATMENT AND TOPCOAT AS REQUIRED PER CESSNA REPAIR DEFINITION S-750-0190/17RD. MECHANICALLY BLENDED APPROXIMATELY 40 AREAS OF CORROSION ON RH UPPER WING SKIN SURFACES. PERFORMED ULTRASONIC THICKNESS AND EDDY CURRENT INSPECTION AND SUBMITTED FINDINGS TO CESSNA FOR REPAIR DISPOSITION. PERFORMED ROTO PEEN, TREATMENT AND TOPCOAT AS REQUIRED PER CESSNA REPAIR DEFINITION S-750-0190/17RD.

Part: SKIN — CORRODED (RT WING) · airframe 14,904 hrs · 8,916 cycles

REPLACED CORRODED RT INBOARD UPPER WING SKIN WITH NEW P/N 6722311-18.

Part: SKIN — CORRODED (LT PYLON) · airframe 14,904 hrs · 8,916 cycles

THREE CORRODED AREAS ON THE CENTER UPPER SKIN OF THE LT PYLON. BLENDED, TREATED, FABRICATED AND INSTALLED DOUBLERS IAW EO ERO-910739, REVISION IR.

Part: SKIN — DAMAGED (HORIZONTAL STAB) · airframe 14,904 hrs · 8,916 cycles

FOUND CORROSION AT TWO LOCATIONS ON THE EXTERIOR SURFACE UPPER SKIN OF THE LT HORIZONTAL STABILIZER, ONE AREA ABOVE THE INBOARD ELEVATOR HINGE AND ONE AREA AT THE OTBD ELEVATOR CUTOUT. MECHANICALLY BLENDED AREAS, PERFORMED ULTRASONIC THICKNESS AND EDDY CURRENT CRACK INSPECTIONS FOR REPAIR DISPOSION. REPLACED BLENDED FASTENERS AS REQUIRED, TREATED, AND TOP COATED AREAS IAW REPAIR DEFINITION S-750-0190/14RD.

Part: SKIN — CORRODED (FUSELAGE) · airframe 14,908 hrs · 8,917 cycles

FOUND CORROSION ON EXTERIOR OF FUSELAGE SKIN AT APPROXIMATELY FS400 AT STRINGERS 3L, 3R, AND 4R. MECHANICALLY BLENDED, MEASURED, TREATED, AND REPLACED FASTENERS AS REQUIRED PER REPAIR DEFINITION S-750-0190/16RD.

Part: WARNING LIGHT — FALSE ACTIVATION (PAX DOOR) · airframe 14,081 hrs · 8,380 cycles

CABIN DOOR OPEN MESSAGE INFLIGHT, DURING DESCENT CABIN ALTITUDE RED MESSAGE DISPLAYED. REQUIRING RAPID DESCENT. INFLATED DOOR SEALANT, NO DEFECTS NOTED. GAINED ACCESS TO MED SWITCHES & CLEANED & INSPECTED RIBBING AS REQUIRED. PURGED DOOR SEAL AS REQUIRED IAW MM 52-70-00. OPS & LEAK CHECKED GOOD.

Part: COALESCER BAG — ODOR (AC BAY) · airframe 13,779 hrs · 8,190 cycles

REPEAT WRITE UP. THE ODOR COMING OUT OF BOTH PAC'S IS UNBEARABLE WITH APU RUNNING, BURNED OIL AND FISHY ODOR. INSPECTED APU FOR OIL RESIDUE NO OIL RESIDUE WAS FOUND. REMOVED OLD COALESCER SOCKS INSTALLED NEW COALESCER SOCKS. OPS CHECK AND LEAK CHECK GOOD. WORK DONE IAW MM CH 21-51-00.

Part: DOWNLOCK SWITCH — FAILED (MLG) · airframe 10,492 hrs · 6,248 cycles

WE HAD NO GREEN NOSE GEAR INDICATION WHEN THE GEAR WAS SELECTED DOWN FOR LANDING. WE HAD 2 MAIN AND THE RED UNLOCK LIGHT WAS OUT. WE RAN THE APPROPRIATE CHECKLIST WHICH INVOLVED BLOWING THE GEAR DOWN WITH THE BACK UP PNEUMATIC BOTTLE. REPLACED THE NOSE GEAR DOWNLOCK SWITCH WITH A NEW UNIT IAW MM 32-30-03, REV 42. OPS CHECKS GOOD. RESET AND SERVICED EMERGENCY GEAR BOTTLE AND BLED LANDING GEAR SYSTEM.

Part: UNKNOWN — MALFUNCTIONED (YAW DAMPER) · airframe 10,228 hrs · 6,093 cycles

DURING CLIMBOUT, CYAN YAW DAMPER FAIL UPPER A MESSAGE APPEARED. PFD WAS SELECTED TO RT SIDE AND UPPER RUDDER B WAS ILLUMINATED. MESSAGE STAYED ON FOR REMAINDER OF FLIGHT AND TAXI IN. COULD NOT DUPLICATE DISCREPANCY ON GROUND. PERFORMED YSAC SYS OPS CHECKS. FOUND NORMAL. CHECKED GROUNDS & RUDDER SURFACE POSITION SENSORS. FOUND TO BE NORMAL. REPOSITIONED YSAC A&B. PERFORMED YSAC SYSTEM TEST, ALL NORMAL. WORK DONE IAW MM 27-24-01. OPS CHECKED NORMAL.

Part: O-RING — LEAKING (HYD MANIFOLD) · airframe 6,931 hrs · 4,101 cycles

AFTER TAKEOFF THE HYD A VOLUME BEGAN TO DECREASE APPROX 1PERCENT EVERY 6 MINS. VOLUME WENT FROM 53 PERCENT TO 33 PERCENT ON TAXI IN. ACCESSED PTO PUMP AREA. RAN A SYS, B SYS AND PTU AND AUX PUMP. FOUND AUX PUMP HYD MANIFOLD FITTING LEAKING, REMOVED MANIFOLD. REPLACED ALL O-RINGS ON MANIFOLD. NOTED EXACT LEAK SOURCE TO BE ERODED O-RING AND LOOSE MANIFOLD PLUG. REINSTALLED MANIFOLD. LEAK CHECK GOOD. WORK DONE IAW MM 20-10-10 R22.

Part: STRUT — LEAKING (NLG) · airframe 6,512 hrs · 3,837 cycles

THE LANDING GEAR HANDLE WOULD NOT MOVE AFTER TAKE-OFF. TROUBLESHOT TO NOSE LANDING GEAR. WITH NOSE SIMULATOR INSTALLED AND BOTH MAIN GEAR WITH WEDGES, THE GEAR SOLENOID TRIPS. JACKED NOSE LANDING GEAR. NOTICED THAT FLUID LEAKING OUT LOWER STRUT AFTER JACKING FOUND THAT WITH TIRES OFF GROUND. HAD TO PUSH ON THE TIRE TO EXTEND THE STRUT, STRUT REQUIRES REPACKING. REMOVED AND REPLACED UPR AND LOWER BARRELS IAW CMM CHAPTER 32-20-02. OPS CHECK GOOD.

Part: HANDLE — INOPERATIVE (MLG)

THE LANDING GEAR HANDLE WOULD NOT MOVE AFTER TAKEOFF. (S)

Part: BRAKE ASSY — MALFUNCTIONED (MLG) · airframe 5,578 hrs · 3,296 cycles

MAIN GEAR ON LT SIDE APPEARS TO SENSE A LOCKED CONDITION DURING NORMAL BRAKING. BRAKES ON LT SIDE RELEASE MOMENTARILY DURING LANDING ROLL DURING SPEEDS OF AROUND 90 KTS. 09-27-07 PERFORM POWER BRAKE AND ANTI-SKID FUNCTIONAL CHECK OPS CHECK GOOD. PERFORMED A COMPLETE BRAKE BLEED. INSPECTED ALL BRAKES FOR WEAR. WEAR CHECKS GOOD. WORK DONE IAW CHAPTER 32-42-00 OF THE CITATION 750 M.M.

Part: COALESCER BAG — ODOR (CABIN AIR) · airframe 5,310 hrs · 3,137 cycles

SMOKEY ODOR IN CABIN, NO VISIBLE SMOKE. [SUP 05-22-07] REMOVED BOTH COALESCERS COCKPIT IS CLEAN. CABIN HAS OIL INSIDE SEPERATOR AND SOCK IS SATURATED WITH OIL. CLEANED SEPERATOR AND REPLACED SOCK. REMOVED AND REPLACED CABIN ACM. RAN ACM AND LEAK CHECKS GOOD. OPS CHECKS GOOD. ALL WORK IAW HAMILTON SUNDSTRAND MM 21-50-03.

Part: UNKNOWN — ODOR (COCKPIT) · airframe 5,259 hrs · 3,102 cycles

NOXIOUS BURNED OIL ODOR IN COCKPIT DURING GROUND OPS. [SUP 05-03-07] GAINED ACCESS FOR APU FOUND OIL LEAK AT CHIP DETECTOR PLUG . BURN OIL TRAVELING IN THE CABIN. FIXED AND CLEANED OIL LEAK. OPS CHECKED AND LEAK GOOD. MAINTENANCE PERFORMED IAW CESSNA CITATION 750-AMM 49-10-00.

Part: UNKNOWN — UNKNOWN · airframe 5,183 hrs · 3,058 cycles

CRUISING AT 9,000 FEET WITH A/P ON, THE TRIM CLACKER CAME ON CONTINUOUSLY TO FULL NOSE DOWN, THEN THE FGC A FAILED AND KICKED OFF A/P. REPLACED FAILED ECM. OPS CHECKED OK. IAW. CE 750 M/M 27-40-00.

Part: UNKNOWN — UNKNOWN (STAB) · airframe 5,131 hrs · 3,027 cycles

WHEN SWITCHING FROM FGS (A) TO FGS (B) THE CLACKER COMES ON IMMEDIATELY AND DOES NOT STOP. THE STAB DOES NOT MOVE. SWITCHING BACK TO FGS (A) CANCELS THE CLACKERS. REMOVE AND REPLACED FGC CONTROLLER WITH REPAIRED UNIT FROM HONEYWELL RS LV2R992K PER CESSNA 750 MAINT. MANUAL CHAPTER 22-10-03. GROUND OP'S CHECKED GOOD.

Part: UNKNOWN — UNKNOWN (ELEVATOR CLACKER) · airframe 5,114 hrs · 3,016 cycles

ELEVATOR TRIM AUDIO (CLACKER) BEGINS RUNNING CONTINUOUSLY DURING FLIGHT WITH AUTOPILOT ON BUT NO TRIMMING ACTUALLY OCCURS. THIS ONLY HAPPENS WHEN FLIGHT GUIDANCE (B) IS SELECTED AND THE AUDIO STOPPED WHEN FLIGHT GUIDANCE TO (A). THIS HAS OCCURRED DURING CRUISE AT HIGH ALTITUDE AND ALSO AT LOW ALTITUDE DURING APPROACH. CONNECTED EXTERNAL POWER. BROUGHT UP AVIONICS SYSTEM "CLACKER" OPS CHECKS GOOD. RAN AUTOPILOT AT INTERVALS OVER A 2 HR PERIOD. COULD NOT DUPLICATE.

Part: WARNING SYSTEM — MALFUNCTIONED (AUTOPILOT SYS) · airframe 5,098 hrs · 3,007 cycles

AFTER ONE HOUR OF CRUISE FLIGHT THE TRIM CLACKER ACTIVATED AND RAN CONTINUOUSLY (AUTO-PILOT WAS NOT TRIMMING) AT LOWER ALTITUDES AND HIGHER TEMPS THE CLACKER SILENCED AND WORKED NORMALLY. C/W AUTOPILOT GROUND FUNCTIONAL CHECKS. SYSTEM OPS CHECKS GOOD ON GROUND IAW 750 MM 22-10-00.

Part: HOSE — LEAKING (HYD SYSTEM) · airframe 4,918 hrs · 2,914 cycles

DURING FINAL APPROACH THE GEAR WAS SELECTED DOWN AND THE (A) HYDRAULIC QTY FELL TO 6 PERCENT WITH (HYD VOL LOW) CAS MESSAGE. JACKED AIRCRAFT, REMOVED PANEL 184DB AND FOUND THE RT GEAR MLG ACTUATOR RETRACT HOSE ASSY HAD A HOLE IN IT.

Part: FLAPPER VALVE — INOPERATIVE (FUEL TANK) · airframe 4,715 hrs · 2,798 cycles

AT FL260 LEVEL FLIGHT-3000 LBS PER WING 0 FUEL IN CENTER TANK, WING TANK O'FULL L CAS AND SAW FUEL VENTING OVERBOARD, TURNED OFF LEFT CENTER TO WING XFER-LOST 300 LBS OF FUEL THEN IT STOPPED, DID IT AGAIN 5 MINS LATER AND LOST ANOTHER 100 LBS. REMOVED AND REPLACED LT WING SURGE TANK FLAPPER VALVE IAW 750 MM CHAPTER.

Part: CHECK VALVE — STUCK (FUEL CROSSFEED) · airframe 4,531 hrs · 2,675 cycles

DURING FLIGHT AT 27,000 FT WITH FUEL X FEED SELECTED FROM RT TO LT (2710 RT TANK AND 2720 LT TANK ) WING TANK O FULL LCAS MESSAGE CAME ON . SHUT FUEL X FEED OFF AND PREFORMED CHECKLIST. FUEL WAS VENTING FROM LT OVERFULL TANK. STARTED DOWN AND CAS MESSAGE EXTINGUISHED WITH FUEL CONTINUING TO VENT FROM LT O FULL TANK FOR APPROX 2 MIN. INSPECTED LT WING SURGE TANK AND PLUMBING. FOUND THE CHECK VALVE THAT ALLOWS SURGE TANK TO DRAIN WAS STUCK CLOSED. CLEANED CHECK VALVE AND REINSTALLED. FUELED AIRPLANE, OPERATIONAL AND LEAK CHECKS GOOD. WORK PERFORMED IAW MM 28-43-00.

Part: CHECK VALVE — STUCK (FUEL CROSSFEED) · airframe 4,531 hrs · 2,675 cycles

DURING FLIGHT AT 27,000 FT WITH FUEL X FEED SELECTED FROM RIGHT TO LEFT (2710 RIGHT TANK AND 2720 LEFT TANK ) WING TANK O FULL LCAS MESSAGE CAME ON . SHUT FUEL X FEED OFF AND PERFORMED CHECKLIST. FUEL WAS VENTING FROM LEFT OVERFULL TANK. STARTED DOWN AND CAS MESSAGE EXTINGUISHED WITH FUEL CONTINUING TO VENT FROM LEFT O FULL TANK FOR APPROX 2 MIN. INSPECTED LT WING SURGE TANK AND PLUMBING. FOUND THE CHECK VALVE THAT ALLOWS SURGE TANK TO DRAIN WAS STUCK CLOSED. CLEANED CHECK VALVE AND REINSTALLED. FUELED AIRPLANE, OPERATIONAL AND LEAK CHECKS GOOD. WORK PERFORMED IN ACCORDANCE WITH 750 MM 28-43-00.

Part: WHEEL — OUT OF BALANCE (MLG) · airframe 3,790 hrs · 2,243 cycles

SEVERE NOSE WHEEL SHIMMY STARTED AT APPROXIMATELY 60 KIAS DURING TAKEOFF ROLL. TAKEOFF ABORTED, MAX SPEED APPROXIMATELY 65 KIAS BEFORE ABORT. INSPECTED NOSE GEAR FOR ANY DEFECTS, NONE NOTED. JACKED NOSE, INSPECTED STEERING UNIT AND NO DEFECTS NOTED. FOUND BOTH NOSE TIRES TO BE WORN TO LIMITS. REMOVED AND RAN BOTH TIRES ON WHEEL BALANCER. FOUND BOTH WHEELS TO BE OUT OF BALANCE. INSTALLED TWO OVERHAULED NOSE WHEEL ASSY'S IAW CH 32-41-00 OF THE CE 750 MM.

Part: STRUT — FAILED (MLG)

AFTER TO GEAR RETRACTION NORMAL, A FEW MINUTES LATER GEAR MOVEMENT TYPE NOISE HEARD WITH NO LIGHTS OR PARTIAL EXTENSION. NOISES FOLLOWED A FEW SECONDS LATER BY RED 'UNLOCK' LIGHT NO EXTENSION AND HYD PRESSURES AND QTY'S NORMAL THROUGHOUT FLIGHT. GEAR EXTENDED NORMALLY WHEN SELECTED DOWN. REMOVED AND REPLACED UPPER & LOWER BARREL ASSY. ON THE NOSE LANDING GEAR DUE TO INTERNAL FAILURE. OPS AND LEAK CHECK NORMAL. WORK IAW CESSNA 750 M/M CHPT 32-20-04.

Part: FLAPPER VALVE — FAILED (FUEL CELL) · airframe 2,576 hrs · 1,542 cycles

INFLIGHT THE WING TANK OVERFILL L CAS MESSAGE CAME ON. THE LEFT WING TANK SHOWED 3200 LBS OF FUEL IN IT AND FUEL STARTED TO VENT OVERBOARD, VENTING STOPPED AT ABOUT 2970 LBS INDICATED IN L WING TANK. AFTER LANDING (20 MIN LATER) CREW NOTICED THE UNDERSIDE OF THE L WING WAS WET. DEFUELED & SUMPED LEFT WING TANK. GAINED ACCESS TO AND INSPECTED CLIMB VENT TUBE AT I/B END OF WING TANK & FOUND IT TO BE POSITIONED & SECURED PROPERLY. INSPECTED SURGE TANK DRAIN LINE FOR CLOGS WITH BOROSCOPE & FOUND NO DEBRIS. REPLACED SURGE TANK DRAIN FLAPPER VALVE P/N 9914475-1 WITH NEW FLAPPER. REPLACED VENT FLOAT VALVE AT O/B END OF WING TANK WITH A SERVICEABLE UNIT. REFUELED WING TANKS & FOUND NO LEAKS.