M250Rolls-Royce (Allison) M250

Parts most often named Bearing (212) · Nozzle (138) · Wheel (76) · Turbine Wheel (69)

TURBINE UNIT WAS RECEIVED FOR LOUD NOISE DURING IDLE AND BAD VIBRATIONS. DURING OVERHAUL INSPECTION THE PT OUTER SHAFT WAS IDENTIFIED WITH A CRITICAL ISSUE, A VISIBLE CRACK IN THE COMPONENT.

IN FLIGHT ENGINE SHUTDOWN. ON TEARDOWN INSPECTION IT WAS DISCOVERED THAT THE 1ST STAGE TURBINE WHEEL BLADES HAD SEPARATED FORM THE BODY OF THE WHEEL. SEE BLOCK 6 BELOW FOR DETAILED INFORMATION ON WHEEL.

DURING MAINTENANCE THE MECHANICS DETERMINED THE FIRST STAGE TURBINE BLADES WERE RUBBING ON THE NOZZLE.ASSEMBLY REMOVED FROM ENGINE

Parts most often named Compressor (64) · Bearing (48) · Gearshaft (43) · Scroll (41)

UPON DISASSEMBLY OF ENGINE FOR 2000HR INSPECTION TECHNICIAN FOUND #2 BEARING RETAINER NUT TO BE LOOSE. REMOVED IT BY HAND.

OPERATOR NOTICE LOSS IN ENGINE POWER. KEYSTONE TESTED THE ENGINE TO VERIFY POWER NUMBERS. TECHNICIAN INSPECTED THE COMPRESSOR TO DISCOVER DIFFUSER VANE ASSEMBLY HAD VANES SEPARATING FROM AFT PLATE. PART PREVIOUSLY OVERHAULED FROM APPROVED VENDOR.

(CAN) IT WAS REPORTED TO BELL: ENROUTE WITH A PASSENGER AND SUSTAINED A SUDDEN POWER LOSS. PILOT AUTOROTATED TO AN OPEN FIELD AND THE LANDING GEAR WAS DAMAGED DURING LANDING BUT AIRCRAFT REMAINED UPRIGHT. INVESTIGATION FOUND THE PC SAFETY VALVE HAD FAILED. NO INJURIES (TC# 20190110019)

Parts most often named Governor (226) · Shaft (9) · Bearing (8) · Spring (8)

(CAN) AIRCRAFT WAS IN FLIGHT AND PILOT NOTICED A DROP IN ENGINE RPM FROM 100% TO 90%. STARTED DECENT ON A BUSH ROAD. GOVERNOR WAS REPLACED WITH A [S/N removed] UNIT. NO DAMAGE OR INJURY (TC# 20190716006)

LOW SIDE GOVERNOR FAILURE, EPO ILLUMINATED, [tail no. removed], [tail no. removed], TORQUE DROP INDICATOR LOSS OF POWER. PILOT LANDED IMMEDIATELY WITHOUT INCIDENT. UPON POWER DOWN THE PILOT LOWERED THE COLLECTIVE AND THE RPM SEEMED TO SPOOL UP AND FLUCTUATE. PILOT ROLLED THROTTLE TO IDLE AND FLUCTUATED AT IDLE AS WELL. PILOT SHUT THE ENGINE DOWN. REPLACEMENT OF THE GOVERNOR REPAIRED THE PROBLEM. THIS UNIT HAD GONE IN FOR REPAIR 3 TIMES BEFORE THE RPM AND ADJUSTMENT ISSUES. TSO 1372.6 TREM 627.4

(CAN) DURING ACFT RUN UP AND PRE TAKEOFF CHECKS THE PILOT WAS UNABLE TO OBTAIN FULL MAIN ROTOR RPM. THE ACFT WAS SHUTDOWN AND MAINTENANCE CONTACTED. THE AME FOUND THE ENGINE GOVERNOR ARM TO BE SEIZED. THE ENGINE GOVERNOR ASSEMBLY WAS REPLACED AND THE ACFT RETURNED TO [S/N removed]. THE TORQUE ON THE NUT SECURING THE ARM TO THE GOVERNOR WAS CHECKED AND FOUND CORRECT, IF THIS NUT IS OVER TIGHTENED IT CAN CAUSE BINDING.

Parts most often named Engine (211) · Bearing (26) · Fireshield (7) · Coupling (4)

THIS IS TO REPORT A NEW EVENT FOLLOWING SDR NO. 2120-0663. THE REPAIRED ENGINE WAS TAKEN OUT OF [S/N removed] FOR THE ENGINE SMOKE WHEN ENGINE TRANSITIONS FROM FLY TO IDLE. TROUBLESHOOTING WAS CARRIED OUT PER THE ROLLS ROYCE MANUAL. NO DISCREPANCIES WERE NOTED. THE REPAIR WAS PERFORMED BY PHI AS PREVIOUSLY NOTED. PHI WAS NOTIFIED ABOUT THE EVENT. THIS EVEN OCCURRED APPROXIMATELY 65 HOURS AFTER REPAIR OF A SIMILAR ISSUE DESCRIBED IN THE SDR NOTED EARLIER IN THIS DESCRIPTION.

UPON LANDING NOTICED COPIOUS AMOUNTS OF SMOKE BILLOWING FROM THE EXHAUST. SHUTDOWN AND NOTED THAT THE ENGINE OIL SITE GLASS WAS EMPTY.

IN FLIGHT, SMOKE ACCUMULATED IN THE CABIN COMING FROM THE HEATING SYSTEM. PILOT TURNED OFF THE HEATING SYSTEM AND SMOKE DISSIPATED. UPON LANDING, IT WAS FOUND #1 BEARING WAS LEAKING AROUND THE SEAL RESULTING IN THE SMOKE IN THE BLEED AIR SYSTEM.

Parts most often named Hmu (36) · Fuel Control (35) · Governor (18) · Actuator (10)

PILOT GOT RESTART FAULT ON CAUTION PANEL. CODES EXTRACTED WAS WFMVRTFLT INDICATING ISSUE WITH FUEL METERING VALVE POTENTIOMETER.

RESTART FAULT LIGHT ILLUMINATED IN FLIGHT. FUEL METERING VALVE POTENTIOMETER FAULT. WFMV FAULT & WFMV RATE FAULT RECORDED ON FADEC.

AFTER ESTABLISHING CRUISE FLIGHT ON THE WAY TO A SCENE LOCATION AND NOT UTILIZING REMAINING POWER AVAILABLE PILOT PULLED MORE COLLECTIVE TO EXPEDITE EN-ROUTE TIME. ONCE REACHING APPROXIMATELY 85% TRQ, TRQ DROPPED WITHOUT PILOT MANIPULATION, OVERCORRECTED AND THEN SETTLED, CAUSING THE AIRCRAFT TO YAW. HMU WAS TROUBLE SHOT AND FOUND TO BE FAULTY.

Parts most often named Filter (47) · Chip Detector (11) · Seal (9) · Line (9)

UPON REMOVAL OF THE OIL CHECK VALVE FOR ROUTINE TESTING, THE AMT NOTICED NO OIL FLOWED OUT OF THE LINE GOING TO THE 6&7 BEARING. THE CHECK VALVE WAS FOUND TO BE STICKING OPEN ALLOWING OIL TO FLOW BACK INTO THE GEARBOX WHICH COULD DELAY OIL FLOW TO THE BEARING ON STARTUP. THE AMT WAS A BLT TO UNSTICK THE VALVE BUT IT IMMEDIATELY GOT STUCK OPEN AGAIN WHILE TESTING THE VALVE. THE PART WAS REPLACED WITH A NEW UNIT.

ON CLIMB OUT, ENGINE OIL FILTER CAUTION LIGHT ILLUMINATED. PROCEDURE IS LAND AS SOON AS PRACTICAL. I WAS OVER A NUMBER OF BUILDING AND ALREADY HEADED FOR THE AIRPORT AND CONTINUED TO LAND ON THE RAMP. INSPECTION AFTER SHUTDOWN SHOWED APPROPRIATE ENGINE OIL LEVEL, NO LEAKS AND NO IMPENDING BYPASS BUTTON POPPED. FOLLOWED PMIC PROCESS, WROTE UP DISCREPANCY AND CONTACTED ALL THE APPROPRIATE PEOPLE. REMOVED AND REPLACED SCAVENGE OIL FILTER

PILOT REPORTED INCREASE IN ENGINE OIL PRESSURE AND DECREASE IN TRANSMISSION PRESSURE. UPON FURTHER INSPECTION IT WAS DISCOVERED THAT THE NEWLY INSTALLED PTO SEALS FAILED.

Parts most often named Fuel Control (104) · Fcu (43) · Bearing (7) · Ecu (5)

PILOT GOT RESTART FAIL LIGHT ON CAUTION PANEL. TESTING UNIT REVEALED ERRATIC READINGS OF THE FUEL METERING VALVE POTENTIOMETER.

FIRST FUEL CONTROL UNABLE TO ADJUST START , SECOND FUEL CONTROL WAS UNABLE TO START AT ALL, REPLACED FUEL CONTROL DISCREPANCY WAS FIXED. THIS WAS ALL IN A YEARS TIME. ON AIRCRAFT 748 THE FUEL CONTROL WAS CHANGED DUE TO THE THROTTLE ARM WAS DIFFICULTY TO ROTATE. ON AIRCRAFT 774 THE FUEL CONTROL WAS CHANGED DUE TO STARTING ISSUES AND THE SECOND ONE WAS CHANGED DUE TO [tail no. removed] HUNTING. SO 5 FUEL CONTROLS WERE REPLACED WITHIN 2020 TOO 2021. NONE OF THE FUEL CONTROLS MADE IT TO THE REQUIRED 2500 OVERHAUL TIME.

DURING MAINTENANCE GROUND RUN CHECK OPERATIONS ENGINE FUEL WAS NOTICED COMING OUT OF THE FUEL CONTROL CASE AND LEAKING TO THE GROUND. FUEL CONTROL WAS REMOVED FOR INVESTIGATION AND A [S/N removed] UNIT INSTALLED.

Parts most often named Bearing (33) · Gear (25) · Gearbox (22) · Pinion Gear (12)

THE ENGINE WAS REMOVED. METAL NOTED ON CHIP PLUGS. DISASSEMBLED THE GEARBOX AND FOUND THE PICKUP ON 3 & 4 BEARING SEPERATORS. REPLACED THE 3 & 4 ROLLER BEARINGS.

(CAN) AN EXCESSIVE OIL LEAK AT TURBINE/GEARBOX JOINT WAS DISCOVERED DURING A DAILY INSPECTION. FURTHER INVESTIGATION SHOWED THE GEARBOX FLANGE APPEARS TO BE CRACKED. THE ENGINE GEARBOX WAS REPLACED AND SENT FOR REPAIRS. THE GEARBOX TSO 4552.9 AND TSN 11,440.5.

(CAN) AN ENGINE CHIP LIGHT OCCURRED. AFTER AN INSPECTION IT WAS FOUND THAT THE 2.5 BEARING WAS THE METAL AND THE 2.5 BEARING DAMAGED THE SPUR ADAPTER GEAR SHAFT ON THE COMPRESSOR.

Parts most often named Bearing (40) · Gearshaft (15) · Seal (15) · Gear (13)

PILOT REPORTED AN ENGINE CHIP LIGHT DURING APPROACH TO LANDING. MAINTENANCE FOUND ACCEPTABLE CHIPS ON UPPER AND LOWER PLUGS. THE PLUGS WERE CLEANED AND REINSTALLED AND A PENALTY RUN WAS PERFORMED. THE PLUGS WERE RECHECKED AND FOUND CLEAN. AIRCRAFT WAS RETURNED TO [S/N removed].

PILOT REPORTED AND ENGINE CHIP LIGHT AND PERFORMED AN UNSCHEDULED LANDING. MAINTENANCE FOUND 1 SLIVER ON THE UPPER GEARBOX CHIP PLUG. THE PLUG WAS CLEANED AND A PENALTY ENGINE RUN WAS PERFORMED IN REFERENCE TO THE ENGINE OMM. THE PLUGS WERE FOUND CLEAN AND THE AIRCRAFT WAS PLACED BACK IN [S/N removed].

ON DISASSEMBLY OF THE ENGINE, METAL WAS FOUND IN THE GEARBOX. NR 3 ROLLER BEARING EXHIBITED METAL PICKOUT IN SEPERATOR POCKETS. INSTALLED A NEW BEARING.

Parts most often named Combustion Liner (34) · Combustion Case (33) · Liner (14) · Combust Chamber (13)

AIRCRAFT INDICATED ABNORMALLY HIGH OPERATING TEMPERATURE. VISUAL INSPECTION FOUND COMBUSTION CAN CRACKED NEAR FUEL NOZZLE MOUNTING POINT

ENGINE REMOVED 12/31/2019 DUE TO SCHEDULE CHANGE FOR TURBINE OVERHAUL (WHEEL RETIREMENTS). FOUND OUTER COMBUSTION CASE CRACKED AROUND FUEL NOZZLE WELD. M250-C47 [S/N removed] CEB A-72-6085 REV 3 ENGINE, COMBUSTION ASSEMBLY - INSPECTION OF OUTER COMBUSTION CASE P/N M250-10404 PREVIOUSLY COMPLIED WITH BULLETIN AT 15 HOURS PRIOR TO CRACK AT FUEL NOZZLE BORE. REPLACED COMBUSTION CASE WITH OVERHAULED PART.

(CAN) PILOT NOTED HIGHER THEN NORMAL TOT TEMPERATURES IN FLIGHT, PILOT LANDED AT THE HANGER AND UPON FURTHER INVESTIGATION FOUND RT BURNER CAN ARMPIT CRACKED.