N107BH
Registered owner: BIGHORN AIRWAYS INC, WY (owner ≠ operator)
Operators of this aircraft
Who operated this tail, and how firmly we know it.
| Operator | Role | Period | Basis |
|---|---|---|---|
| BIGHORN AIRWAYS, INC. (BIGA) | Certificate holder | — | Matched by certificate designator |
Accident & incident history
No NTSB accidents or incidents on file for this aircraft.
Maintenance disclosures
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 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.
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.
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)