BIGHORN AIRWAYS, INC.

THE CREW WAS CONDUCTING A MAINTENANCE ACCEPTANCE FLIGHT ON AIRCRAFT FOR THE REPLACEMENT OF LEFT AND RIGHT PROPELLERS. THE NTS SHUTDOWN PROCEDURE WAS BEING PERFORMED IN-FLIGHT AS REQUIRED ON THE RT ENG. DURING THE NTS SHUTDOWN, THE RT PROPELLER DID NOT FULLY FEATHER & COPILOT PULLED FURTHER BACK ON THE EMERGENCY SHUTDOWN HANDLE TO FULLY ACTUATE THE FEATHERING VALVE. THIS CAUSED THE RT ENG SHUTDOWN LINKAGE TO BIND. THE COPILOT TRIED TO RETURN EMERGENCY SHUTDOWN HANDLE TO NORMAL POSITION & WOULD NOT MOVE. CREW MADE DECISION TO LEAVE ENG & PROP (FULLY FEATHERED AT THIS TIME) SHUTDOWN & RETURN TO KSHR ON LT ENG FOR A SINGLE ENGINE LANDING. MX INSPECTED RT ENG SHUTDOWN LINKAGE AND DISCOVERED BINDING HAD OCCURRED AT THE TELEFLEX CABLE JUST PRIOR TO THE EMERGENCY SHUTOFF VALVE. IT WAS ALSO DISCOVERED THAT THE FEATHERING VALVE DID NOT FULLY ACTUATE DUE TO RIGGING. THE TELEFLEX CABLE WAS TAKEN APART, CLEANED, REASSEMBLED AND EMERGENCY SHUTDOWN RIGGING WAS PERFORMED WITH NO FURTHER DISCREPANCIES NOTED.

AILERONS WERE BEING MOVED THROUGH THEIR RANGE DURING STATIC TRAINING AND IT WAS NOTED THAT THEY WERE STIFF AND AN ODD SOUND WAS REPORTED. UPON INVESTIGATION A TECHNICIAN FOUND THAT THE ROUTING THROUGH THE CENTER WING BOX PULLEY AT STATION 442 WAS INCORRECT, LEADING TO FRAYING OF THE AILERON CONTROL CABLE, CAUSED BY RUBBING AGAINST THE PULLEY CABLE GUIDE/RETAINING PIN. THE AIRCRAFT WAS ALREADY REMOVED FROM SERVICE FOR ANOTHER DISCREPANCY AND REMAINS SO UNTIL DISCREPANCIES ARE CORRECTED.

AIRCRAFT DEPARTED KSHR AT 1840Z FOR A MAINTENANCE FLIGHT. DURING CLIMB OUT THE PILOT ASKED THE COPILOT TO MOVE THE TEMPERATURE CONTROL HANDLE FOR HEAT. THE COPILOT OPENED THE HEAT VALVE WITH THE TEMPERATURE CONTROL HANDLE AND EXPERIENCED A SLIGHT "POP". THE HEAT REMAINED IN THE OPEN POSITION FOR A BRIEF TIME UNTIL THE CREW HAD SMOKE IN THE CABIN AND COCKPIT. THE COPILOT ATTEMPTED TO SECURE THE TEMPERATURE CONTROL HANDLE, BUT COULD NOT RETURN THE HANDLE TO THE OFF POSITION DUE TO BINDING. THE CREW IMMEDIATELY RETURNED TO KSH WHERE THE AIRCRAFT WAS INSPECTED FOR THE CAUSE OF THE BINDING AND SMOKE. DURING THE INVESTIGATION IT WAS NOTED THE RIGHT ENGINE BLEED VALVE LINKAGE WAS SLIGHTLY MISADJUSTED CAUSING THE VALVE LEVER AND LINKAGE TO BIND IN AN OVER-CENTER POSITION RESULTING IN THE BLEED VALVES STAYING OPEN. THIS RESULTED IN DAMAGE TO THE INTERIOR INSULATION BLANKETS INSTALLED NEXT TO THE HEATING DUCT AND THIS IS BELIEVED TO BE THE SOURCE OF THE SMOKE. THE LINKAGE WAS ADJUSTED AND AIRCRAFT HEATING SYSTEM WAS OPERATED DURING A GROUND RUN WITH NO FURTHER ADVERSE EFFECTS.

ELECTRIC PITCH TRIM MALFUNCTION WITH AUTO-PILOT DISENGAGED. ELEVATOR TRIM RUN AWAY IN THE UP DIRECTION. PILOT WAS ABLE TO OVERRIDE PITCH WITH YOKE AND DISABLED MALFUNCTION BY PULLING AUTOPILOT 115VAC CIRCUIT BREAKER. AIRCRAFT RETURNED TO FT. WAINWRIGHT WITH NO FURTHER ISSUES. SYSTEM WAS INSPECTED AND AUTOPILOT COMPUTER RESEATED IN RACK. SYSTEM OP-CHECKS PERFORMED AND EVALUATION FLIGHT WAS CONDUCTED WITH NO FURTHER ISSUES.

UNCOMMANDED RH ENGINE SHUTDOWN.

DURING A MAINTENANCE ACCEPTANCE FLIGHT, SOMETIME AFTER INITIATING CABIN HEAT, IT WAS NOTICED THAT THE FLIGHT STATION WAS BECOMING HAZY. THE PILOT LOOKED AFT AND SAW THAT THE CABIN WAS ALSO HAZY. CABIN HEAT WAS SECURED, AND THE AIRCRAFT VENTILATED. SUBSEQUENT GROUND INVESTIGATION REVEALED AN INSULATION BLANKET IN CONTACT WITH THE CABIN BLEED AIR TUBE. INSULATION BLANKETS WERE RESECURED AND RESTORED TO ORIGINAL CONFIGURATION. PERFORMED CHECKS AND OPERATION OF CABIN HEAT WITH NO DEFECTS NOTED.

DURING ROUTINE INSPECTION, ON FRAME 6 UNDER THE FLOORBOARDS AT APPROXIMATELY BL 700(LT), THE FRAME ANGLE WAS FOUND CORRODED WITH A SUBSEQUENT CRACK IN THE SUPPORTING ANGLE UNDERNEATH IT.

DURING FLIGHT INTO ICING CONDITIONS THE WINDSHIELD HEAT WAS SELECTED ON AND THE POWER TERMINAL OF THE COPILOT’S WINDSHIELD EXHIBITED ARCING. WINDSHIELD HEAT WAS DE-SELECTED AND THE APPROPRIATE CIRCUIT BREAKERS WERE PULLED. DURING GROUND SYSTEM TROUBLESHOOTING IT WAS DETERMINED THAT THE POWER TERMINAL AT THE BASE OF THE WINDSCREEN HAD BECOME LOOSE AND THE RELATIVE MOVEMENT BETWEEN THE TERMINAL LUG AND THE TERMINAL BLOCK WAS THE REASON FOR THE ARCING. THE TERMINAL LUG WAS SECURED TO THE WINDSHIELD TERMINAL BLOCK WITH A SCREW AND FLAT WASHER. REVIEW OF THE AIRCRAFT MAINTENANCE MANUALS, SPECIFICALLY CHAPTERS 56, 30-40-10, AND 24, AS WELL AS THE ILLUSTRATED PARTS CATALOG, DO NOT PROVIDE INFORMATION ON THE PROPER HARDWARE STACK-UP OR TORQUE REQUIRED FOR TERMINAL(S). THE TIME ON THE WINDSCREEN IS UNKNOWN BUT LISTED AS 1000 HRS/CYCLES BELOW.

THE RIGHT FIRE CONTROL BOX FLASHED A FIRE WARNING WHILE IN FLIGHT. TROUBLESHOOTING REVEALED THE BOX WAS FAULTY AND IT WAS REPLACED WITH A SERVICEABLE UNIT. NO FURTHER INDICATIONS WERE OBSERVED.

THE RESTRICTOR VALVE ASSEMBLY (ATTACHED TO THE SHUTTLE VALVE ON THE NOSE LANDING GEAR ACTUATOR) BLEW OUT IT'S BODY SEALING O-RING LEADING TO COMPLETE HYDRAULIC FLUID LOSS AFFECTING STEERING, BRAKING AND FLAP ACUATION. THIS HAPPENED ON TAXI FOR FLIGHT. THE LANDING GEAR REMAINED DOWN AND LOCKED. THE AIRCRAFT WAS TOWED BACK TO PARKING AND SUBSEQUENT MAINTENANCE AS A SAFETY PRECAUTION AS DIFFERENTIAL ENGINE POWER WAS THE ONLY STEERING METHOD AVAILABLE AFTER THIS FAILURE. THE VALVE WAS RESEALED WITH A NEW O-RING AND HAD THE SAME FAILURE AFTER ONE FLIGHT, AT WHICH TIME THE RESTRICTOR VALVE WAS REPLACED WITH A NEW UNIT. THIS FAILURE IS UNDER FURTHER INTERNAL COMPANY INVESTIGATION AS PART OF OUR CASP PROGRAM. THE TIME ON THE PART IS UNKNOWN BUT LISTED AS 1000HRS/CYCLES BELOW.

INITIAL REPORTS WERE OF AN SMOKE IN THE COCKPIT, NOTICED HYDRAULIC FLUID ON THE WINDOWS INTERNALLY AND EXTERNALLY AND HYDRAULIC FLUID FROM THE RADOME TO THE RAMP DOOR DRIPPING OFF THE BELLY. HYDRAULIC FLUID SEEMED TO BE CONCENTRATED ON THE RIGHT (CO-PILOT) SIDE OF THE NOSE. IT WAS ALSO NOTED THAT THE INTERIOR SEEMED TO HAVE A OILY RESIDUE LIKELY FROM THE MISTING OIL. UPON OPENING THE RADOME IT WAS COMPLETELY COVERED IN HYDRAULIC FLUID. THE MAIN SYSTEM HYDRAULIC PRESSURE STAINLESS BRAIDED FLEX LINE LINE TO THE MAIN SYSTEM GAUGE LOOKED LIKE RUBBER WAS PUSHING THOUGH THE BRAIDING. A SMALL PILE OF RUBBER PARTIALS WERE BELOW THE HOSE. THEN TURNING ON THE HYDRAULIC PUMP AND THE HYD. LINE INSTANTLY PRODUCE A FINE MIST OF HYDRAULIC FLUID THAT FILLED THE NOSE QUICKLY. THEN CLEANED UP THE NOSE AREA AND INSPECTED THE AREA, SERVICED THE SYSTEM WITH ONE GALLON OF HYDRAULIC FLUID, THE HYDRAULIC LINE WAS REPLACED AND PRESSURE CHECK WITH NO LEAKS NOTED. IN ADDITION MAINTENANCE HAS RE-INSPECTED BEHIND THE RADOME AFTER THE FOLLOWING FLIGHT TO THE BACK OF THE INSTRUMENT PANEL CLEANING UP RESIDUAL FLUID AND PUTTING ANOTHER SET OF EYES ON ALL THE WIRING WITH POWER AND AVIONICS ON NO ELECTRICAL SMELL WAS NOTED.

RIGHT ENGINE SURGED, UP TO 100% AND COULD NOT BE REDUCED. CHIP DETECTOR LIGHT CAME ONE AND OIL PRESSURE WENT TO ZERO. PILOT FOLLOWED EMERGENCY PROCEDURES SHUT DOWN ENGINE AND RETURNED TO THE NEARBY AIRPORT. AFTER LANDING THE ENGINE PROPELLER COULD NOT BE ROTATED. THE CHIP DETECTOR SHOWED SIGNIFICANT METAL DEPOSITS, BUT THE OIL BYPASS INDICATOR PIN WAS NOT POPPED. ENGINE REMOVED. FOUND THAT THE BULL GEAR FAILED CAUSING EXTENSIVE DAMAGE TO VARIOUS OTHER COMPONENTS IN THE GEAR BOX.

THE RIGHT ENGINE INBOARD ACCESS COWLING (PN: 212-53105-1) DISENGAGED ALLOWING THE COWLING TO OPEN IN FLIGHT. THE COWLING DID NOT DEPART THE AIRCRAFT. THE LATCHES WERE CLOSED AND LOCKED, BUT THE FORWARD LATCH SHOWED SIGNS WEAR TO THE HOOK AND MOST LIKELY DISENGAGED ALLOWING THE AIR-STREAM TO ENTER THE COWLING OVERLOADING THE 2 REMAINING LATCHES.

UPON AN ENGINE GROUND RUN FOR THE PURPOSE OF AN AIRCRAFT IN STORAGE ENGINE 7 TO 30 DAY INHIBITING RUN. ENGINE OPERATION PERFORMANCE WAS NOTED TO BE UNUSUAL WITH INDICATIONS OF A POSSIBLE STICKING COMPRESSOR BLEED OFF VALVE. UPON INVESTIGATION AND REMOVAL OF THE VALVE, VALVE SHAFT FUNCTION WAS NOTED TO BE UNSERVICEABLE DUE TO STICKING AND POOR SEALING OF THE VALVE CONTACT AREA. THE VALVE WAS REPLACED WITH ANOTHER SERVICEABLE VALVE. ENGINE AND OPERATION CHECKS CARRIED OUT WITH ALL INDICATIONS AND PARAMETERS NOW NORMAL IAW THE AIRCRAFT AND ENGINE MAINTENANCE MANUAL REQUIREMENTS. THE UNSERVICEABLE VALVE HAS BEEN RETURNED TO THE SUPPLIER AND FORWARDED ONTO PRATT AND WHITNEY FOR INVESTIGATION PURPOSES. RESULTS OF INVESTIGATION ARE STILL PENDING AT THIS TIME.

THE PILOT REPORTED AN OIL LEAK AND FLUCTUATING OIL PRESSURE ON THE RIGHT ENGINE. MAINTENANCE FOUND THE ENGINE 4 QTS LOW ON OIL, CLEANED ENGINE AND COWLINGS, AND SERVICED ENGINE OIL. THE ENGINE WAS MOTORED AND A THE OIL LEAK WAS LOCATED ON THE .125 INCH STAINLESS STEEL LINE FROM THE GOVERNOR TO THE PROP PITCH CONTROL. THE LINE WAS CRACKED AROUND THE CIRCUMFERENCE AT THE BASE OF THE FLARE. THE LINE WAS REPLACED WITH A SERVICEABLE LINE AND ENGINE WAS RUN UP, LEAK CHECKED AND RETURNED TO SERVICE. THE STAINLESS 1/8 INCH LINE IS SHORT AND ACCESS TO IT IS LIMITED. IF THE GOVERNOR AND PROP PITCH CONTROL FITTINGS ARE NOT PROPERLY ALIGNED IT IS POSSIBLE TO PRE-LOAD IT MAKING IT SUSCEPTIBLE TO A STRESS FRACTURE.

A VIBRATION WAS NOTED ON THE RIGHT PROPELLER DURING ENGINE RUN UP DURING MAINTENANCE, PROP DYNAMIC BALANCE WAS FOUND OUT OF LIMITS (2.5 IPS). THE PROPELLER WAS FOUND TO HAVE 3 BLADES SLIP IN THE CLAMPS CAUSING 2 BLADES TO BE OVER 1.5 DEGREES OFF FROM THE REST. THE RIGHT PROP WAS REMOVED AND REPAIRED BY AN APPROVED REPAIR STATION. THE RIGHT ENGINE WAS INSPECTED BY MAINTENANCE PERSONNEL FOR DAMAGE. THE RIGHT OUTBOARD ENGINE MOUNT ATTACH POINT ON THE MAGNESIUM GEARBOX WAS FOUND TO BE BROKEN. THE LOWER 2 MOUNT BOLTS WERE BROKEN OFF ABOUT 1/2" BELOW THE HEADS. APPROXIMATELY A 2-1/2" X 1" PIECE WAS BROKEN OFF THE GEARBOX MOUNTING AREA. THE ENGINE WAS REMOVED FOR REPAIR. APPARENT CAUSE: PROPELLER VIBRATION CAUSED BY 2 BLADES OF THE 4 BLADES BEING 1 1/2* TO 2* OFF PITCH. FATIGUE CAUSING 2 OF THE FOUR ENGINE MOUNT TO GEAR BOX BOLTS TO BREAK OFF. THE REMAINING BOLTS TAKING ALL THE LOADING CAUSING THE CASE TO CRACK AND BREAK OUT. ONLY 1 OF THE FOUR BOLTS MAY HAVE BEEN HOLDING ANY OF THE LOADING.

THE PILOT NOTED A LT ENG OIL PRESS FLUCTUATION, THEN DURING CLIMB TO 2000 FT, THEN THE LOW OIL PRESS LIGHT CAME ON & TORQUE FLUCTUATION OCCURRED. THE PILOT PERFORMED AN INFLIGHT SHUTDOWN & RETURNED. LANDED WITHOUT INCIDENT. PERSONNEL FOUND THE OIL TUBE, PN 896963-1, FROM THE BETA MANIFOLD TO THE PROP PITCH CONTROL TO BE MISALIGNED & LEAKING. THE PART WAS REPLACED WITH A SERVICEABLE TUBE & ADDED 2QTS OF OIL. GND RUN UP & LEAK CHECKS WERE GOOD.

RT INBD AILERON HINGE BRACKET FOUND TO HAVE EXFOLIATION CORROSION AT AIRFRAME ATTACH POINT, REQUIRING REPLACEMENT OF PART. OTHER CONTROL SURFACE HINGES/ATTACH BRACKETS INSPECTED WITH NO DEFECTS.

AFTER CONFIRMING A BLEED AIR SEAL COUPLING LEAK ON SDR BIGA20160114-001, THE ACFT FIRE DETECTION SYS WAS GND TESTED NORMAL. A TEST FLIGHT WAS REQUESTED, DURING THE FLIGHT THE LT FIRE DETECTION FLICKERED. AGAIN THE SYS WAS TESTED ON THE GND & COULD NOT BE DUPLICATED, THE ENG FIRE LOOPS WERE SWAPPED FROM THE LT ENG TO THE RT ENG & ALL CONNECTIONS WERE INSPECTED, CLEANED & REASSEMBLED. GND CHECKS WERE NORMAL, TWO TEST FLIGHT WERE PERFORMED & THE PROBLEM COULD NOT BE DUPLICATED. THE SUSPECTED HARNESS MAY HAVE HAD A CONNECTION PROBLEM THAT WAS NOT IDENTIFIED, THAT WAS CORRECTED DURING THE FIRE LOOP REMOVAL & INSTALLATION.

PILOT WAS PERFORMING A NIGHT CURRENCY FLIGHT, AS HE BEGAN HIS FINAL APPROACH THE LT ENG FIRE WARNING CAME ON. THE PILOT PULLED BACK POWER & THE FIRE LIGHT WENT OUT BELOW 40% TORQUE. PUSHING THE POWER UP CAUSED THE LIGHT TO COME BACK ON. THE PILOT LANDED WITHOUT INCIDENT. INSPECTED THE ACFT, NO HEAT DAMAGE, OR FIRE COULD BE FOUND & THE SYS GND TESTED NORMAL. THE ACFT WAS GND RUN & THE PROBLEM COULD NOT BE DUPLICATED. FOUND ONE BLEED AIR DUCT COUPLING & CONNECTOR SEEMED LOOSE GOING FROM THE ENG COMPARTMENT INTO THE AIRFRAME. THE SYS WAS PRESS CHECKED & FOUND EXCESSIVE LEAKAGE. THIS BLEED AIR LEAKAGE WAS INLINE WITH THE FIRE DETECTION WIRE LOOP. THE COUPLING SEALS WERE REMOVED & FOUND TO BE WORN & HARD. THE SEALS IN THE COUPLER & CONNECTOR WERE REPLACED & THE ACFT WAS GND RUN & TESTED NORMAL.

DURING A TRAINING FLIGHT THE PILOT ATTEMPTED TO EXTEND THE GEAR & HAD THE 5 AMP LG CONTROL CB POP. THE PILOT EXTENDED THE GEAR USING THE NITROGEN BLOW DOWN SYS IAW THE POH & AFM, THE GEAR WAS DOWN & LOCKED WITH 3 GREEN INDICATIONS. THE SYS WAS TROUBLE SHOT & DUPLICATED ON THE GND, A WIRE OFF THE RT MLG UPLOCK SWITCH WAS GROUNDING OUT IN THE RT WING CAUSING THE PROBLEM. THE WIRING WAS REPAIRED, SECURED GEAR & CYCLED 15 TIMES. BLOW DOWN BOTTLE SERVICE & RETURNED TO SERVICE.

DURING INSPECTION, THE AILERON CONTROL ROD WAS FOUND TO BE WORN APPROX 15% OF THE THICKNESS. THE ROD WAS WORN FROM THE AILERON GUST LOCK SYS & SEEMS ONLY WEAR ON THE PILOTS OTBD SIDE DUE TO A SLIGHT MISALIGNMENT OF THE GUST LOCK.

THE FUEL CONTROL UNIT , FCU, WAS SENT OUT FOR BENCH CHECK & REPAIR DUE TO A SUSPECTED FUEL FLOW PROBLEM. THE FCU WAS BENCH CHECKED & THE PROBLEM COULD IT WAS SLIGHTLY OUT OF RIG THAT MAY HAVE BEEN CAUSING A GOVERNOR INTERFERENCE PROBLEM. IT ALSO HAD THE DRIVE SPLINE INSPECTION PERFORMED ON THE FCU IAW THE REQUIREMENTS OF AD 2006-15-08 & COUNCIL 331 AMOC & APPROVED FOR RETURN TO SERVICE. THE UNIT WAS REINSTALLED & A GND RUN WAS ATTEMPTED. THE START WAS SLOW, BUT ACCELERATED PAST 60% WHERE THE TECHNICIAN ATTEMPTED TO PULL IT BACK FROM FLIGHT IDLE BACK TO GND IDLE, BUT IT CONTINUED TO ACCELERATE UNCONTROLLABLY THE TECHNICIAN IMMINENTLY PULLED THE STOP & FEATHERED & PREVENTED ANY ENG DAMAGE. AFTER SEPARATING THE FCU FROM THE FUEL PUMP THE FCU DRIVE HAD TWISTED OFF & SHEARED. THE TECHNICIAN NOTICED SOME BINDING WHEN TRYING TO TURN THE FCU DRIVE. SUSPECTS A BEARING FAILURE IN THE FCU. INSPECTION OF THE FCU WAS COMPLETED. THE PRIMARY CAUSE OF THE FAILURE TO INNER INPUT SHAFT WAS A BEARING PN 1412-612 CAUSING BEARING SEPARATION & LOCKING UP THE FCU DRIVE. A DETERMINATION OF THE BEARING FAILURE COULD NOT BE DETERMINED.

THE LEFT GENERATOR SYSTEM KICKED OFF LINE. AFTER TROUBLESHOOTING THE SYSTEM THE 20 GAUGE "D" WIRE WAS FOUND TO BE BROKEN INSIDE THE SHEATH IN THE ENGINE COMPARTMENT AND WAS ONLY DETECTABLE BY OHM CHECKING THE HARNESS. DURING THE OHM READING CHECKS OF THE GENERATOR SYSTEM A SECONDARY PROBLEM WAS FOUND WITH HIGH RESISTANCE ON THREE WIRES AT THE LEFT GCU CANNON PLUG. THEY WERE BREAKING AWAY AT THE AT THE PINS DOWN IN THE PLUG PAST THE STRAIN RELIEF. THESE WERE ALL REPAIRED. VIBRATION AND THE FREQUENT REMOVAL OF THE GCUS AND STARTER GENERATORS FOR REPLACEMENT, TROUBLESHOOTING, AND INSPECTION MAY BE LEADING TO THE WIRING TO BREAKDOWN.

THE AIRCRAFT WAS TEST FLOWN FOR NTS SHUTDOWN WHICH REQUIRES THE SHUTDOWN OF THE NR 2 ENGINE IN FLIGHT. THE SPEED LEVER WAS PULLED OVER THE GATE AND INTO THE STOP AND FEATHER POSITION, THE MANUAL FUEL SHUTOFF CUT THE FUEL TO THE ENGINE, BUT THE FEATHER VALVE DID NOT COMPLETELY ENGAGE CAUSING THE PROPELLER TO NOT FULLY FEATHER AND MAINTAIN 10% RPM. THE PILOT ATTEMPTED TO PUT THE SPEED LEVER FORWARD AND RESTART THE ENGINE, BUT COULD NOT BE PUT FAR ENOUGH FORWARD TO RESET THE MANUAL FUEL SHUT OFF VALVE. THE PILOT MADE A ONE ENGINE LANDING PAFB. AFTER INSPECTION OF THE SPEED LEVER / STOP AND FEATHER CONTROL IT WAS FOUND THAT SOME OF THE ADJUSTMENTS FOR GROUND IDLE MAX RPM CAUSED THE ROD TO THE UNDERSPEED GOVERNOR TO GO OVERCENTER WHEN PULLED ALL THE BACK TO STOP AND FEATHER ON THE SPEED LEVER. THE PROBLEM DID NOT OCCUR EVERY TIME THE SPEED LEVER WAS CYCLED, BUT HAD THE POTENTIAL TO LOCK UP. THE RIGGING WAS RE-ADJUSTED AND THE NTS SHUT DOWN WENT NORMALLY. DUE TO THE DESIGN OF HAVING THE STOP AND FEATHER ON THE SPEED LEVER SMALL ADJUSTMENTS TO THE RPM CAN CAUSE THE LINKAGE TO LOCK UP WHEN PULLED BACK TO STOP AND FEATHER EVEN IF TESTED ON THE GROUND THE LINKAGE MUST BE CHECKED IF ITS CLOSE TO A OVER-CENTER CONDITION.

AFTER RETURNING TO DEPARTURE, THE PILOT LOST FULL BRAKING POWER ON THE LT BRAKE AND REPORTED A "SPONGY" CONDITION AND WAS UNABLE TO PUMP UP BRAKE PRESSURE. THE ACFT LEFT MASTER CYLINDER WAS REMOVED AND DISASSEMBLED FOR INSPECTION. THE BRAKE FLUID COMING OUT OF THE WAS CONTAMINATED WITH BLACK MATERIAL FROM THE O-RINGS. THE INTERIOR WAS INSPECTED AND FOUND UN-SCORED. THE MASTER CYLINDER WAS RE-PACKED WITH NEW O-RINGS, BRAKE SYS FLUSHED, BLED, AND OPS CHECKED NORMAL.

AFTER RETURNING THE PILOT REPORTED A "SPONGY" LEFT BRAKE AND REDUCED BRAKING DURING TAXI. THE MASTER CYLINDER WAS DISASSEMBLED. THE FLUID OUT OF THE CYLINDER WAS BLACK AND APPEARED TO HAVE BLACK O-RING MATERIAL CONTAMINATING THE FLUID. THE MASTER CYLINDER WAS CLEANED, INSPECTED, AND REPACKED WITH NEW O-RINGS. THE SYSTEM WAS FLUSHED, BLED, AND OPS CHECKED NORMAL. THE O-RINGS APPEARED VERY WORN.

DURING INSP THE BRAKE PADS WERE NEAR WEAR LIMITS, AFTER JACKING THE ACFT, IT WAS FOUND THAT THE BRAKES WERE DRAGGING EXCESSIVLY ON THE LT AND RT SIDE. THE LT CALIPER PN 5006484-3 WAS EXCHANGED FOR AN O/H BRAKE ASSY AND THE RT BRAKE WAS BROKEN DOWN FOR REPAIR (PAD REPLACEMENT). AFTER THE RT BRAKE CALIPER ASSY WAS DISASSEMBLED IT WAS FOUND THE BACKING PLATE PN 5006480 WAS CRACKED AND REQUIRED REPLACEMENT. THE BRAKE WAS REASSEMBLED AND OPS CHECKED NORMALLY. LATER IT WAS DISCOVERED THAT THE LT BRAKE ASSY THAT WAS REMOVED FOR THE O/H UNIT ALSO HAD A CRACKED BACKING PLATE AND NEED A NEW ONE INSTALLED. THESE CRACKS MAY BE CONTRIBUTING TO THE BRAKE DRAGGING PROBLEM ALSO ALLOWING THE SELF AJUSTERS TO EXTEND TOO FAR WITH THE BACKING PLATE FLEXING CAUSING THE DRAG.

AFTER START UP AND ATTEMPTING TO TAXI THE LT AND RT BRAKES WOULD NOT RELEASE PROPERLY AFTER HAVING THE PARKING BRAKE SET. BOTH BRAKE ASSEMBLIES (PN 5006484-3) WERE SENT OUT FOR OVERHAUL. THE BACKING PLATE (PN 5006180) FOR BRAKE ASSY SN APR84-161 WAS FOUND CRACKED AND REQUIRED REPLACEMENT. THE TIME ON THE COMPONENT IS UNKOWN.

THE ACFT WAS PERFORMING A TEST FLIGHT FOR A NTS AND FLIGHT IDLE FF DECENT CHECK AFTER THE INSTALLATION OF A O/H LT ENG AND A REPAIRED LT PROPELLER. WHILE PERFORMING THE FLIGHT IDLE FUEL FLOW FOR SINK RATE THE ACFT BEGAN TO VIBRATE BADLY. IT WAS QUICKLY IDENTIFIED AS THE LT ENGINE AS BEING THE PROBLEM. THE FLIGHT CREW PERFORMED A STOP AND FEATHER SHUTDOWN OF THE LT ENGINE. THE ENGINE SHUTDOWN PROPERLY BUT ONLY 2 OPPOSITE BLADES WENT TO FEATHER, BUT THE OTHER 2 BLADES DID NOT, 1 WAS IN REVERSE AND THE OTHER WAS FLAT. AFTER LANDING IT WAS DISCOVERED THAT THE 2 BLADES IN QUESTION HAD THE PINS THAT LINKED THE BLADE CUFF TO THE DOME WERE MISSING ON THE BLADES THAT WERE REMOVED DURING THE REPAIR AT THE PROPELLER SHOP. THE PROPELLER HAD NO OTHER DAMAGE AND WAS SENT OUT FOR REPAIR AND TESTING. THE LT ENGINE WAS REMOVED DUE TO THE TORQUE INDICATING SYS INTERNAL TO THE ENGINE BEING DAMAGED DUE TO THE VIBRATION AND SENT OUT FOR REPAIR.

DURING INSPECTION IT WAS FOUND THAT THE UPPER SUPPORT TRUNNION HOLDING THE TOP OF THE NOSE GEAR STRUT WAS HITTING THE MOUNT ON THE FUSELAGE. IT LOOKED AS THOUGH THE TRUNNION WAS INSTALLED UPSIDE DOWN DUE TO THE COLLAR HITTING THE EDGE OF THE FUSEALGE MOUNT, AND THE INSTALLATION OF THE BUSHING INSERTS IN THE UPPER SUPPORT TRUNNION AND THE BUSHINGS IN THE MOUNT ON THE FUSELAGE. AFTER REVIEWING THE MAINTENANCE MANUAL AND IPC IT WAS INSTALLED PER THE MANUFACTURES INSTRUCTIONS. IT WAS DISCOVERED THAT THE MM AND IPC WERE IN ERROR IN THE ENGLISH TRANSLATION. THE TRUNNION WAS FLIPPED OVER SO THE BUSHING FLANGES WERE FACE TO FACE GIVING CLEARANCE AND THE AREA TREATED AND TOUCHED UP TO PREVENT CORROSION.

STHE AIRCRAFT HAD THE LEFT ENGINE FLAME OUT ON DESCENT WHILE RUNNING ON THE LEFT MAIN TANK. THE PILOT SWITCHED TANKS TO THE AUX THEN RE-SELECTING THE LEFT MAIN TANK THE AIRCRAFT WAS RESTARTED AND LANDED WITHOUT FURTHER INCIDENT. THE AIRCRAFT WAS HANGERED AND MAINTENANCE SUMPED IT FOR SUSPECTED WATER DUE TO THE COLD WEATHER, NONE WAS FOUND. THE AIRCRAFT WAS REFUELED AND FOUND THE LEFT AUX DRY. GROUND RUNS WERE PERFORMED AND IT RAN PROPERLY ON BOTH THE LEFT MAIN AND AUX TANKS. AFTER RETURNING TO HOME BASE WITHOUT INCIDENT, A TEST FLIGHT WAS PERFOMRED IN AN ATTEMPT TO RE-CREATE THE PROBLEM. IT WAS FOUND THAT IF THE LEFT TANK SELECTOR WAS MOVED SLOWLY FROM THE LEFT AUX TANK TO THE LEFT MAIN TANK AND LEFT JUST BEFORE THE INDENT IT WAS POSSIBLE TO HAVE THE FUEL QUANITY TO INDICATE THE LEFT MAIN WHILE LEAVING ON THE BOOST PUMP AND RUNNING ON THE LEFT AUX TANK. AFTER THE TEST FLIGHT A SLIGHT ADJUSTMENT WAS MADE TO THE MICRO-SWITCHES ON THE LEFT FUEL SELECTOR TO ALLOW THE PUMP AND FUEL INDICATION TO SWITCH SOONER AND NOT SO CLOSE TO THE LEFT MAIN DETENT MATCHING THE RIGHT FUEL SLECTOR PER THE CESSNA SM.

ON THE LT ENG WITH THE SPEED LEVERS EET AT 100 PERCENT AND YOU TRY TO BRING THE POWER LEVER BACK TO CRUISE, AT ABOUT 70 PERCENT TO 80 PERCENT TORQUE THE RPM DROPS TO 93 PERCENT. TORQUE TEMP AND FUEL FLOW WILL INCREASE TO A HIGHER SETTING ON ITS OWN MAKING CONTROL OF THE PROP DIFFICULT. PILOT PERFORMED OF A COMMANDED ENG SHUTDOWN ON THE LT ENG AND LANDED NORMALLY. (K)

DURING CLIMB OUT, THE PILOT NOTICED THE RIGHT ENGINE OIL PRESSURE GAGE INDICATING A SIGNIFICANT INCREASE IN PRESSURE. WHEN THE RIGHT ENGINE STARTED TO RUN ROUGH THE ENGINE WAS SECURED AND THE PROPELLER WAS FEATHERED AS A PRECAUTION. THE AIRCRAFT RETURNED TO THE AIRPORT OF DEPARTURE AND LANDED WITHOUT FURTHER PROBLEMS. AFTER THE RIGHT COWLING WAS REMOVED TO INVESTIGATE THE ROUGH RUNNING ENGINE, IT WAS FOUND THAT THE ENGINE HAD BLOWN THE NUMBER 4 CYLINDER OFF OF THE CRANKCASE, ALLOWING THE PISTON TO COCK IN THE CYLINDER BARREL AND THROWING THE NUMBER 4 ROD, DAMAGING THE CRANKCASE. THE ENGINE CANNOT BE ROTATED BY HAND.

DURING ROUTINE INSPECTION, CRACK IN ACCESSORY GEARBOX WAS NOTED. CRACK WAS LOCATED AT RT SIDE ENGINE MOUNT PAD. UPON ENGINE REMOVAL, CRACK WAS FOUND TO BE ALMOST COMPLETELY THROUGH ENGINE MOUNT PAD AREA.

AIRCRAFT EXPERIENCED PARTIAL LOSS OF POWER DUE TO FAILURE OF NR 3 CYLINDER EXHAUST VALVE. AIRCRAFT TERMINATED FLIGHT AND LANDED WITHOUT FURTHER INCIDENT.

CYLINDER HEAD SEPERATED FROM BARREL DURING CLIMB OUT. ENGINE FEATHERED AND AIRCRAFT LANDED SAFTELY. CYLINDER HEAD CRACKED ABOVE THREADED AREA TO BARREL.

CRACKS FOUND ON RIB NR 12 ON RIGHT SIDE AND RIB NR 13 ON LEFT SIDE. LT RIB CRACKED THROUGH 4 RIVETS HOLES ON TOP SKIN, LENGTH OF CRACK WAS 5 INCHES. RT RIB CRACKED THROUGH 1 RIVET HOLE, LENGTH OF CRACK WAS 2 INCHES. CRACKS WERE FOUND DURING COMPLIANCE WITH AD 2001-21-01 AND DORNIER SB228-234.

LT MLG DOWN LIGHT FAILED TO ILLUMINATE ON APPROACH. EMERGENCY GEAR SYSTEM ACTIVATED. AIRCRAFT LANDED SAFELY AT MAIN BASE. FOUND LT MLG DOWNLOCK SWITCH ACTUATOR BROKEN.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. APPEAR TO BE MANUFACTURING DEFECTS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. APPEAR TO BE MANUFACTURING DEFECTS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. APPEAR TO BE MANUFACTURING DEFECTS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. FOUR CLAMPS IN 201 HOURS. ALL CLAMPS APPEAR TO BE MANUFACTURING DEFECTS. NON LIFE LIMITED CLAMPS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. TWO CLAMPS IN LAST 200 HOURS. BOTH APPEAR TO BE MANUFACTURING DEFECTS. NON LIFE LIMITED CLAMPS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. APPEAR TO BE MANUFACTURING DEFECTS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. APPEAR TO BE MANUFACTURING DEFECTS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. APPEAR TO BE MANUFACTURING DEFECTS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. APPEAR TO BE MANUFACTURING DEFECTS.

NEW AEROQUIP EXHAUST CLAMPS ARE CRACKING AROUND OUTER PERIPHERY. APPEAR TO BE MANUFACTURING DEFECTS.

CRACK DISCOVERED DURING ROUTINE 100 HOUR INSPECTION. DETECTED VISUALLY. REASON FOR CRACK NOT KNOWN. CLAMP ASSEMBLY REPLACED WITH FACTORY NEW UNIT.