N1566C

Part: SWITCH — INOPERATIVE (NLG)

PILOT REPORTED NO NOSE GEAR DOWN INDICATION FOR LANDING. MAINTENANCE VERIFIED FAILURE OF THE NOSE GEAR ACTUATOR DOWN LOCK SWITCH-REPLACED NOSE GEAR ACTUATOR.

Part: ANNUNCIATOR — INOPERATIVE (MLG INDICATOR)

PILOT REPORTED THAT THE NOSE GEAR DOWN AND LOCK GREEN LIGHT WAS INTERMITTENT. MAINTENANCE REPLACED THE GEAR DOWN AND LOCK ANNUNCIATOR. (M)

Part: CONNECTOR — DIRTY (MLG)

AT LANDING IN ANCHORAGE, THE GEAR GREEN SAFE LIGHT DID NOT ILLUMINATE FOR 30 SECONDS AFTER THE SECOND EXTENSION ATTEMPT. THE LANDING WAS COMPLETED WITHOUT INCIDENT. MAINTENANCE COULD NOT DUPLICATE THE PROBLEM AND CLEANED CONNECTORS AND PERFORMED A SATISFACTORY OPERATIONAL CHECK FLIGHT. (M)

Part: O-RING — DISPLACED (THROTTLE)

RIGHT THROTTLE FROZE AT ALTITUDE. MAINTENANCE FOUND THE NR 2 AIR SEAL, AT CENTER CONSOLE DISPLACED. REPLACED CONTROL ASSEMBLY. (M)

Part: CONNECTOR — DIRTY (DOWNLOCK SWITCH)

AT LANDING IN ANCHORAGE, PILOT REPORTED HAD TO PUMP THE LANDING GEAR HAND PUMP TO RECEIVE A GREEN SAFE NOSE GEAR ILGHT, HANDLE WARNING WAS NOT ILLUMINATED. MAINTENANCE COULD NOT DUPLICATE, CLEANED NOSE GEAR ACTUATOR AND DOWNLOCK SWITCH CONNECTORS, CHECKED NOSE GEAR WIRING AND FROZE SWITCHES. NO FAULTS FOUND. (M)

Part: PUMP — MALFUNCTIONED (RT ENG FUEL)

ON TAKE OFF ROLL, PRIOR TO LIFT OFF, RT ENG EXPERIENCED COMPLETE LOSS OF POWER AND TAKE OFF WAS ABORTED. NR ENGINE SPOOLED DOWN, CREW SECURED IT IAW PROCEDURE. AC RETURNED TO RAMP WITHOUT FURTHER INCIDENT. POST SHUT DOWN INSP DID NOT REVEAL ANY ABNORMALITY AND ENG STATED AND OPERATED TO FULL POWER WITHOUT FAULT. MAINTENANCE REPLACED NR 2 ENG HP FUEL PUMP FOR T/S AND PERFORMED A GROUND RUN. UPON REACHING HIGH THEN RAN SUCCESSFULLY FOR ADDITIONAL TWO RUNS. MAINT REPLACED THE LOW PSI FUEL PUMP FOR T/S AND COMPLETED AN ADDITIONAL SERIES OF SUCCESSFUL RUNS WITHOUT FAULT. INSP OF REMOVED COMPONENTS DID NOT DISCLOSE ANY OBVIOUS FAULTS.(K)

Part: RING ASSEMBLY — LOOSE (ENGINE)

DURING HSI INSPECTION, THE CT VANE RING SEGMENTS WERE NOTED BEING LOOSE. THE HOT SECTION WAS REPLACED DUE TO THIS CONDITION. AS THE ASSY WAS SET ON A WORK BENCH, MULTIPLE SHROUD SEGMENTS WERE OBSERVED TO FALL OUT OF PLACE, HAD THIS OCCURRED DURING ENG OPERATION, ENGINE WOULD HAVE EXPERIENCED A CATASTROPHIC INTERNAL FAILURE DUE TO CONTACT OF THE COMPRESSOR TURBINE BLADES WITH THE SEGMENTS. A REVIEW OF THE VANE RING ASSY INDIVIDUAL PN INDICATES THAT THE REASON THE SEGMENTS WERE NOT RETAINED WAS DUE TO IMPROPER MATCH. BETWEEN THE COMPRESSOR TURBINE STATOR ASSY AND SHROUD HOUSING. THE REMOVED ASSY DID NOT HAVE PROVISIONS FOR RETAINING THE AXIAL MOVEMENT OF THE SHROUD SEGMENTS.

Part: DIAPHRAGM — LEAKING (FUEL PUMP)

ON THE RAMP, THE PILOT REPORTED FUEL LEAKING FROM THE INBOARD NR 1 ENGINE DRAIN LINE. MAINTENANCE DISCOVERED THE LOW PRESSURE FUEL PUMP WAS REPLACED. DISASSEMBLY OF THE PUMP REVEALED THAT THE DIAPHRAGM IN THE PRESSURE ADJUSTING VALVE HAD A HOLE IN IT. FURTHER INSPECTION DETERMINED THAT THE PN RA531 DIAPHRAGM CONTROL PLATE, THAT CONTACTS THE DIAPHRAGM, DID NOT CONFORM TO THE LEAR SIEGLER/ ROMEC PLATE DESIGN DRAWING FOR FINAL FINISH OF THE OUTER CIRCUMFERENCE OF THE PLATE. SHARP EDGES THAT REMAIN ON THIS PLATE HAVE THE CAPACITY TO CAUSE A HIGH RATE OF WEAR ON THE RUBBER DIAPHRAGM, CAUSING EARLY FAILURE OF THE DIAPHRAGM AND RESULTING IN FUEL LEAKAGE.

Part: SHAFT — SHEARED (PAX DOOR HANDLE)

AFTER LANDING, PILOT REPORTED INTERIOR CABIN DOOR HANDLE INOPERATIVE. MAINTENANCE REMOVED THE HANDLE AND FOUND THE DRIVE SHAFT SHEARED. MAINTENANCE REPLACED THE HANDLE ASSEMBLY AND FOUND NO OTHER PROBLEMS.

Part: SWITCH — OUT OF ADJUST (GEAR PWR LEVER)

ON APPROACH TO LANDING, GEAR WARNING SYSTEM (REDUCED POWER WITH GEAR UP) DID NOT FUNCTION EVEN WITH POWER LEVERS FULLY RETARDED. MAINTENANCE CORRECTED THE PROBLEM BY ADJUSTMENT OF THE POWER LEVER GEAR UNSAFE WARNING MICRO SWITCHES.

Part: OIL COOLER — CRACKED (NR 2 ENG OIL)

PILOT REPORTED THAT, AFTER LANDING, HE OBSERVED ENGINE OIL LEAKING FROM THE NR 2 ENGINE. THE OIL LEVEL WAS VERIFIED TO BE JUST INDICATIONS OF OIL PRESSURE LOSS, FLUCTUATION OR HIGH TEMP. MAINTENANCE REPLACED THE OIL COOLER AND LATER VERIFIED THAT IT WAS CRACKED (BENCH CHECK VERIFIED LEAK AT A CRACKED ENDI PLATE WELD). (K)

Part: WIRE — BROKEN (NR 2 ENG OIL IND)

AFTER TAKEOFF, NR 2 ENGINE OIL PRESSURE INDICATED (0) UNTIL POWER WAS REDUCED TO 1700 LBS TORQUE. RETURNED TO AIRPORT FOR AN UNEVENTFUL LANDING. MAINTENANCE REPAIRED A BROKEN WIRE AT THE NR ENGINE OIL PRESSURE TRANSMITTER CONNECTOR.

Part: BLADE — FAILED (LT ENGINE)

JUST AFTER TAKEOFF, THE LT ENGINE MADE A LOUD NOISE AND TORQUE DROPPED OFF. THE ENGINE WAS SECURED AND THE AIRCRAFT RETURNED AND LANDED WITHOUT INCIDENT. MAINTENANCE DETERMINED A FAILURE OF THE CT DISK BLADES, CAUSE UNKNOWN. THE ENGINE WAS REMOVED FOR REPAIR.

Part: FITTING — LEAKING (HYD SYSTEM)

ON DEPARTURE, THE GEAR WARNING LIGHTS (HANDLE) CAME ON. THE GEAR WOULD NOT CYCLE WITH THE ELECTRIC PUMP. THE GEAR WAS EXTENDED WITH THE HAND PUMP. THE CREW CONTINUED THE FLIGHT AS REQUIRED TO BURN FUEL DOWN TO LANDING WEIGHT AND THE AIRCRAFT MADE AN UNEVENTFUL RETURN LANDING. MAINTENANCE FOUND THE HYDRAULIC SYSTEM LOW ON FLUID AND A LARGE QUANTITY OF HYDRAULIC FLUID AROUND AND LEAKING FROM THE RETRACT LINE SWIVEL ON THE NOSE GEAR ACTUATOR. THE FITTING WAS RESEALED USING A CONICAL SEAL INSERT. MAINTENANCE ALSO FOUND THE HYDRAULIC POWER PACK MOTOR CIRCUIT BREAKER POPPED (POSSIBLY DUE TO EXTENDED MOTOR OPERATION DUE TO LOW FLUID LEVEL)

Part: ACTUATOR — FAILED (NLG)

ON APPROACH, NOSE GEAR GREEN DOWN AND LOCKED LIGHT FAILED TO ILLUMINATE AFTER TWO NORMAL CYCLES AND ONE MANUAL EXTENSION. THE AIRCRAFT MADE AN UNEVENTFUL LANDING. MAINTENANCE COULD NOT CONFIRM FAILURE DUE ILLUMINATION OF THE NOSE GEAR GREEN LIGHT AFTER THE AIRCRAFT PARKED AND THE FAILURE COULD NOT BE DUPLICATED. THE NOSE GEAR ACTUATOR WAS REPLACED AND THE AIRCRAFT WAS OPERATIONALLY TEST FLOWN.

Part: DOWNLOCK SWITCH — BROKEN (HARNESS)

ON APPROACH, NOSE GEAR GREEN DOWN AND LOCKED LIGHT FAILED TO ILLUMINATE INITIALLY, IT CAME ON A FEW MINUTES AFTER THE GEAR WAS DOWN. THE AIRCRAFT WAS FERRIED WITH THE GEAR DOWN. MAINTENANCE FOUND ONE WIRE IN THE DOWN AND LOCK SWITCH HARNESS CORRODED AND BROKEN (DUE NICK IN WIRE INSULATION). THE SWITCH WAS REPLACED.

Part: DIAPHRAGM — LEAKING (FUEL PUMP)

PILOT FOUND FUEL LEAKING OUT OF NR 1 ENGINE DRAIN MANIFOLD. THIS AC IS IN COMPLIANCE WITH SB 71-3307 THAT INCORPORATED A DRAIN LINE FROM THE LOW PRESS FUEL PUMP TO THE DRAIN MANIFOLD. DETERMINED THAT DIAPHRAGM IN THE PUMP HAD FAILED AND ALLOWED FUEL TO DRAIN OUT OF DRAIN MANIFOLD. THE VENTED FUEL HAD COVERED THE LEFT MAIN LANDING GEAR WHEELS AND BRAKES. THIS COULD CAUSE FIRE HAZARD IF THE BRAKES BECAME HOT AND/OR SPARKED AFTER LANDING. DUE TO THE COMMON FAILURE OF THE FUEL PUMP DIAPHRAGM (AND ASSOCIATED FUEL VENTING). TO CORRECT PROBLEM WITH THE FUEL PUMP(SMOOTHING EDGES OF DIAPHRAGM PLATE PN RA5361) AND RELOCATING THE PUMP DRAIN LINE TO THE ENG BREATHER LINE (VENTING OUT BEHIND THE GEAR WELL).

Part: DIAPHRAGM — DAMAGED (FUEL PUMP)

PILOT FOUND FUEL LEAKING OUT OF NR 1 ENGINE DRAIN MANIFOLD. DETERMINED THAT THE DIAPHRAGM IN THE PUMP HAD FAILED AND ALLOWED FUEL TO DRAIN OUT OF THE DRAIN MANIFOLD. DUE TO THE COMMON FAILURE OF THE FUEL PUMP DIAPHRAGM (AND ASSOCIATED FUEL VENTING-SB71-3307) TO CORRECT PROBLEM WITH THE FUEL PUMP, INVESTIGATION REVEALED CUTS IN THE DIAPHRAGM CAUSED BY THE SHARP EDGES OF OF DIAPHRAGM PLATE PN RA5361 CREATED AT PRODUCTION. FAILURE OF DIAPHRAGM CAUSES FUEL TO BE DISCHARGED OUT OF THE VENT PORT OF THE PUMP PRESS REGULATOR AND OVERBOARD OR INTO THE ENGINE ACCESSORY AREA. EITHER DRAIN LOCATION CAN CREATE A FIRE HAZARD.

Part: DIAPHRAGM — RUPTURED (FUEL PUMP)

POST RAYTHEON AIRCRAFT SERVICE BULLETIN 71-3307, ENGINE DRIVEN LOW PRESSURE FUEL PUMP DRAIN MOD. EXPERIENCED A FAILURE OF THE LOW PSI ENGINE DRIVEN FUEL PUMP ON THE NR 1 ENGINE. THE RESULT OF THE DIAPHRAGM RUPTURE WAS TO HAVE FUEL VENTED OUT OF THE NACELLE THROUGH THE MANIFOLD DRAIN. THE FUEL, THAT WAS VENTED OUT, COVERED THE LEFT MAIN LANDING GEAR WHEELS AND BRAKES. SUBMITTER STATES THEY CONSIDER THIS A FIRE HAZARD, AS THE BRAKES WERE STILL SOAKED WITH FUEL WHEN THE AIRCRAFT ARRIVED ON THE RAMP FOR PUMP REPLACEMENT. (M)

Part: TERMINAL LUG — MISMANUFACTURED (STARTER/GEN)

THREADED STUD ON THIS TERMINAL ADAPTER LUG HAS IMPROPER THREAD PITCH/DIAMETER FOR PROPER INSTALLATION OF WIRE TERMINAL NUT. IF THE NUT IS THREADED ON THE TERMINAL AS DELIVERED FROM RAYTHEON, THE THREADS ON THE TERMINAL STRIP OUT. IF THE ADAPTER IS USED AS DELIVERED, PROPER TORQUE ON THE TERMINAL NUTS CANNOT BE ASSURED AND RESULTANT LOOSE WIRES AND ARCING CAN OCCUR. THIS CONDITION HAS BEEN NOTED ON THE VAST MAJORTIY OF PREVIOUSLY DELIVERED ADAPTERS AND DIRECT CONTACT WITH RAYTHEON HAS PROVIDED NO IMPROVEMENT IN THE DELIVERED PRODUCT. THIS ADAPTER LUG IS PART OF RAYTHEON 1900C STARTER IMPROVEMENT KIT NR 114-9034-1.

Part: STUD — IMPROPER (STARTER/GEN)

THREADED STUD ON THIS TERMINAL ADAPTER LUG HAS IMPROPER THREAD PITCH/DIAMETER FOR PROPER INSTALLATION OF WIRE TERMINAL NUT. IF THE NUT IS THREADED ON THE TERMINAL AS DELIVERED FROM MFG., THE THREADS ON THE TERMINAL STRIP OUT. IF THE ADAPTER IS USED AS DELIVERED, PROPER TORQUE ON THE TERMINAL NUTS CAN NOT BE ASSURED AND RESULTANT LOOSE WIRES AND ARCING CAN OCCUR. THIS CONDITION HAS BEEN NOTED ON THE VAST MAJORITY OF PREVIOUSLY DELIVERED ADAPTERS AND DIRECT CONTACT WITH MFG. HAS PROVIDED NO IMPROVEMENT IN THE DELIVERED PRODUCT.

Part: SEAL — LEAKING (FLOW DIVIDER)

PILOT REPORTED HEAVY EXHAUST FUMES ENTERING CABIN THROUGH BLEED AIR SYSTEM. THIS WAS THE THIRD REPORT IN A ROW. PREVIOUS REPAIRS INCLUDED REPLACING A CRACKED EXHAUST STACK. COULD NOT DUPLICATE ON GROUND. THE FINAL DISCREPANCY REPAIRED WAS TO REPLACE NR 1 ENGINE FUEL NOZZLE SEALS. THE FINAL DISCREPANCY WAS VERIFIED ON GROUND RUNS AS WAS THE CORRECTION. (M)