O-360Lycoming O-360

Parts most often named Cylinder (57) · Cylinder Head (52) · Pushrod (14) · Exhaust Valve (13)

THIS IS THE FOURTH FACTORY NEW AIRCRAFT WE HAVE RECEIVED IN A ROW FROM ROBINSON HELICOPTER CO WITH THIS ISSUE. ALL PUSHRODS AND ROCKER ARMS WERE FOUND TO BE SORED AT THE MATING SURFACE. PARTS HAVE SINCE BEEN SENT TO RHC AND WE ARE WAITING FOR REPLACEMENT PARTS. WE BELIEVE THAT THIS IS CAUSED BY A LACK OF LUBRICATION AT THIS MATING SURFACE DURING INITIAL RUN UPS OR THE DE-PICKLING PROCESS.

AIRCRAFT WAS IN CRUISE FLIGHT IN BANNER TOW CONFIGURATION. A LOUD AUDITABLE BANG WAS HEARD. ENGINE EXPERIENCED EXTREME VIBRATION FOLLOWED BY TOTAL LOSS OF POWER. PILOT CONDUCTED A FORCED LANDING IN A SOCCER FIELD. UPON ENGINE INSPECTION, #2 CYL. EXPERIENCED EXHAUST VALVE HEAD FAILURE FROM VALVE STEM. THE VALVE HEAD IN TURN PUNCHED A HOLE THRU THE PISTON HEAD. ALUMINUM FLAKES FOUND THROUGH OUT ENGINE, PRESUMABLY FROM PISTON DAMAGE. ENGINE REMOVED FOR REBUILD.

DURING ROUTINE 100 HR INSPECTION FOUND COMPRESSION TO BE 40/80 ON CYLINDER #4 AND INSPECTED FURTHER. FOUND THAT VALVE WAS NOT SEATING PROPERLY. VALVE SEAT WAS BELL MOUTHED, VALVE PUSHES IN AN OUT ON A CURVE RATHER THAN STRAIGHT, WORN ONLY ON ONE SIDE. IMPROPER SEAL WAS ALLOWING BLOW BY AND CAUSING LOW COMPRESSIONS. TIME SOH ON ENGINE IS 385.6 AND TOTAL TIME IS12,634.5. ENGINE ORDERED FROM WESTERN SKYWAYS, DATE OF MANUFACTURING FEB 19 2025 UNDER WORK ORDER W062125.

Parts most often named Magneto (28) · Impulse Coupling (26) · Rotor (21) · Bearing (14)

MAGNETO PULLED DURING ROUTINE MAINTENANCE TO CHECK FOR THE PRESENCE OF A CHAMPION MANUFACTURED IMPULSE COUPLING. ONE WAS FOUND INSTALLED AND THUS REMOVED FOR REPLACEMENT WITH A NEW ES3163 IMPULSE COUPLING. AFTER REMOVAL OF THE OLD IMPULSE COUPLING, I DISASSEMBLED IT FOR AN INSPECTION AND FOUND THAT BOTH RIVETS HOLDING THE PAWLS IN PLACE WERE LOOSE AND FAILING.

MAGNETO P/N 4371 [S/N removed]. LOOSE RIVETS FOUND ON IMPULSE COUPLING DURING 500 HOUR INSPECTION. REPLACED IMPULSE COUPLING WITH NEW.

MAGNETO P/N 4371 [S/N removed]. LOOSE RIVETS FOUND ON IMPULSE COUPLING DURING 500 HOUR INSPECTION. REPLACED IMPULSE COUPLING WITH NEW.

Parts most often named Carburetor (52) · Float (14) · Bracket (4) · Screw (3)

AFTER ONLY 360.49 TACH HOURS IN [S/N removed] FOUND THROTTLE GETTING STUCK BEFORE FULL THROTTLE STOP. SUSPECTED ACCELERATOR PUMP PLUNGER GETTING STUCK NOT ALLOWING THROTTLE ARM TO HIT FULL THROTTLE STOP.

FARGO, ND (FAR): [tail no. removed], P28A, FAR-FAR, DECLARED AN EMERGENCY DUE TO A ROUGH RUNNING ENGINE. ACFT RETURNED TO FAR ARPT, LANDED, AND TAXIED TO THE RAMP WITHOUT FURTHER INCIDENT. 11/15/2024 2238Z. OVERHAULED CARBURETOR INSTALLED ON NOVEMBER 8TH, 2024.

WHERE THE 2 HALVES MEET AND MATE. THE SCREWS HOLDING THEM TOGETHER WERE STILL LOCKED INTO POSITION BY SPECIAL DEVICES. BUT THE HALVES HAD SOME SLIGHT MOVEMENT THAT ALLOWED A SMALL AMOUNT OF FUEL TO LEAK OUT OF THIS POINT. I DID NOT DISASSEMBLE THIS UNIT, BUT I SUSPECT THAT THE THREADS IN THE UNIT OR ON THE BOLTS HAD STRIPPED SLIGHTLY TO ALLOW THIS MOVEMENT.

Parts most often named Crankshaft (25) · Crankcase (14) · Camshaft (11) · Bearing (6)

ON CLIMB TO CRUISING ALTITUDE PIC FELT AN ENGINE VIBRATION AND DECIDED TO TURN BACK TO KARG. ON TURN BACK TO DEPARTURE AIRPORT OIL PRESSURE DROPPED TO "0" AND ENGINE SEIZED. POST EMERGENCY LANDING, ENGINE COWLING WAS REMOVED, HOLE IN CRANKCASE FOUND ON FORWARD TOP PORTION OF ENGINE CASE AT THE NUMBER 1 CYLINDER PUSHROD LOCATION. THE HOLE IN THE ENGINE CRANKCASE CONTRIBUTED TO THE LOSS OF ENGINE OIL PRESSURE AND SUBSEQUENT ENGINE SEIZURE.

PILOT HAD ROUTINE TAKEOFF ABOUT FIVE MINS INTO THE CLIMB ENGINE WAS LOOSING POWER THEN STARTED MAKING KNOCKING SOUNDS THEN OIL PRESSURE LIGHT CAME ON THEN PILOT DECLARED AN EMERGENCY AND LANDED AT A NEARBY AIRPORT. AFTER DISASSEMBLY OF ENGINE FOUND NUMBER TWO AND NUMBER THREE ROD BEARINGS WERE SPUN ALL ROD BOLTS WERE TIGHT AND NO SINGS OF OIL PUMP FAILURE

WHEN POWER REDUCED FROM TAXIING POWER TO IDLE QUICKLY, ENGINE MAKES A FAST TICKING SOUND. PREVIOUS OIL ANALYSIS INDICATED A SLIGHTLY HIGHER COPPER CONTENT IN THE OIL. THE ENGINE WAS RAN BRIEFLY BY TECHNICIANS, NOTED THAT THE ENGINE WAS MAKING A LOUD KNOCKING NOISE. OIL FILTER WAS PULLED AND COPPER FLAKES WERE FOUND THROUGHOUT THE FILTER. ACCORDING TO THE MANUFACTURER THERE IS ONLY ONE BEARING THAT WOULD CAUSE COPPER FLAKES LFOUND IN THE FILTER, THE CONNECTING ROD WRIST PIN BEARINGS .

Parts most often named Air Box (17) · Plate (5) · Control Cable (3) · Air Filter (3)

UPON VISUAL INSPECTION, FOUND THE RIGHT ENGINE CARBURETOR HEAT AIRBOX BACKPLATE (WELD) CRACKED AT TOP LEFT ATTACH POINT. CRACK WAS FOUND NEAR TOP SUPPORT BRACKET. AIRCRAFT USED DAILY FOR FLIGHT TRAINING WITH AN AVERAGE OF 100 HOURS OF FLIGHT TIME EVERY 90 DAYS.

UPON VISUAL INSPECTION, FOUND THE LEFT ENGINE CARBURETOR HEAT AIRBOX BACKPLATE (WELD) STEEL STAPLES WEARING THROUGH ALUMINUM WALL DUE TO AIR VIBRATION WHEN CARB HEAT DOOR IS FULLY DEFLECTED. SHOULD THE STAPLES WEAR THROUGH THE WALL ENTIRELY, FELT DOOR-STOP COULD BE SUCKED DIRECTLY INTO VENTURI OF CARBURETOR CAUSING AN INDUCTION BLOCKAGE AND ENGINE FAILURE. AIRCRAFT USED DAILY FOR FLIGHT TRAINING WITH AN AVERAGE OF 100 HOURS OF FLIGHT TIME EVERY 90 DAYS.

FORM 337 INSTALLED, STC SA01669CH AIR FILTER ELEMENT BECAME HARDENED AND SHRUNK CONSIDERABLY OVER A SHORT [S/N removed] LIFE OF 496.6 HOURS. THESE FILTERS HAVE A 2500.0 HOUR [S/N removed] LIFE. WHEN THESE AIR FILTERS SHRINK THEY PREVENT THE AIR BOX FROM CLOSING PROPERLY, IN RESULT, CRUSHING THE FILTER ELEMENT IF NOT REPLACED. WE INSPECT AND [S/N removed] THE CPE-1104, AIR FILTER ELEMENT EVERY 100HRS IAW THE ICA DOCUMENT 4003, LATEST REV AS SPECIFIED.

Parts most often named Gasket (5) · Oil Filter (3) · Line (3) · Filter (3)

DURING PRE-FLIGHT, THE PILOT DISCOVERED A LARGE OIL SPOT ON GROUND COMING FROM ENGINE COWLING. REMOVED THE ENGINE COWLING, DISCOVERED THE OIL PRESSURE SWITCH TO BE LEAKING.

WHEN A MECHANIC PULLED THE TOP COWLING TO PERFORM ROUTINE MAINTENANCE, HE NOTED OIL WAS ALL OVER THE FIREWALL AND ACCESSORY CASE. INSPECTION REVEALED THE OIL COOLER WAS LEAKING FROM BETWEEN THE PLEATS. THE EXACT QUANTITY OF OIL LOST IS UNKNOWN.

LOSS OF OIL PRESSURE IN FLIGHT, UNSCHEDULED LANDING. FOUND .1250 PIPE PLUG THAT IS NORMALLY INSTALLED IN THE OIL PUMP HOUSING TO HAVE FALLEN OUT. MAX OIL PRESSURE ATTAINABLE WITH OUT THE PLUG WAS 20 PSI. SB555A DEAL WITH THIS ISSUE.

Parts most often named Oil Cooler (26) · Bracket (3) · Hose (1)

DURING PREFLIGHT INSPECTION, THE PILOTS NOTED THERE WAS OIL STREAKING FROM THE LT ENGINE COWLING BACK TO THE T/E OF THE FLAP. INSPECTION BY A MAINTENANCE TECH REVEALED THE OIL COOLER WAS LEAKING AT THE END OF THE COOLER ADJACENT TO THE INLET FITTING. FORTUNATELY, ONLY A SMALL AMOUNT OF OIL WAS VENTED BEFORE THE LEAK WAS FOUND. THE OIL COOLER HAD RECENTLY BEEN INSTALLED IN NEW CONDITION DURING AN ENGINE CHANGE 2 MONTHS PRIOR AND HAD ACCRUED ONLY 128 HOURS TIS.

AFTER A NORMAL FLIGHT, THE PILOTS NOTICED THERE WAS A LARGE OIL STREAK ON THE LT SIDE OF THE ACFT THAT ORIGINATED FROM UNDER THE ENGINE COWL. THEY ALSO NOTED THAT THERE WAS LESS THAN 4 QTS OF OIL IN THE ENGINE, DESPITE LEAVING FOR THE 2 HR FLIGHT WITH OVER 7 QTS. MAINTENANCE PERSONNEL NOTED THE LEAK WAS COMING FROM THE OIL COOLER.

CREW OBSERVED OIL PRESSURE GRADUALLY DECREASING UNTIL OIL PRESSURE ANNUNCIATOR ILLUMINATED ON LT ENGINE. ENGINE WAS SHUTDOWN AND A SINGLE ENGINE LANDING WAS MADE AT HOME AIR FIELD. UPON INSPECTION BY MAINTENANCE THE OIL COOLER WAS FOUND TO HAVE FAILED NEAR THE OUTLET PORT. COOLER WAS REPLACED, ENGINE RAN AND LEAK CHECKED GOOD. COOLER ONLY HAD 14.6 HRS ON IT SINCE O/H, BUT HAD 4099.5 TOTAL TIME.

Parts most often named Mount (23) · Bolt (2) · Rubber Bushing (1) · Bracket (1)

DURING ANNUAL INSPECTION FOUND THE ENGINE MOUNT TUBING HAD CHAFE DAMAGE FROM CONTACT WITH THE THROTTLE CABLE DUE TO IMPROPER ROUTING/CLAMPING OF THE CABLE.

THE LOWER ENGINE MOUNTS RUPTURED CAUSING THE ENGINE TO DROP DOWN. THE ALTERNATE AIR CABLE STARTED TO CHAFE ON THE ENGINE MOUNT FRAME SO THE CABLE THEN CHAFED INTO THE ENGINE MOUNT FRAME MORE WHEN THE ENGINE SHIFTED ON THE MOUNTS THAT NOW HAVE PLAY IN THEN WITH A SAWING ACTION.

(CAN) THE ENGINE MOUNT WAS FOUND CRACKED ON THE LT SIDE ON THE ARM GOING FROM THE FIRE WALL TO THE UPPER LORD MOUNT JUST ABOVE THE WELD LOCATED AT THE FIRE WALL END.

Parts most often named Stop (11) · Hub (6) · Propeller (2) · Fork (2)

DURING INSPECTION, MAINTENANCE NOTED A LOW PITCH STOP TREADS WERE STRIPPED AND DAMAGED HUB THREADS AS WELL. THE PROPELLER WAS SENT OUT FOR REPAIR,

DURING A 100 HOUR INSPECTION, MECHANIC FOUND THE PROPELLER LOW PITCH STOP THREADS STRIPED THAT HOLD THE SPINNER IN PLACE ON CENTER OF THE PROPELLER. SAFETY WIRE IS STILL IN PLACE.

DURING ANNUAL INSPECTION FOUND CRACK EXTENDING THROUGH THE HUB AT ONE OF THE MOUNTING BOLT HOLES. CRACK GOES COMPLETLEY THROUGH THE HUB TO THE INNER BORE OF THE HUB. NO HISTORY OF PROP STIKE OR ANY OTHER VISUAL DAMAGE TO THE PROPELLER. THIS PROPELLER INSTALLED WITH STC NR SA779NE. PROPELLER REMOVED FROM AIRCRAFT AND SENT FOR FURTHER STUDY IAW MFG REQUEST.

Parts most often named Engine (11) · Pushrod (3) · Rocker (2) · Door (1)

DURING ROUTINE MX, LYCOMING SB388C (EXHAUST VALVE GUIDE INSPECTION) FOUND 4 OF 4 EXHAUST ROCKER ARMS, PUSH RODS & LIFTER SOCKETS TO HAVE MECHANICAL DAMAGE "HEAVY SCUFF". LYCOMING FACTORY OVERHAULED, O-360-J2A, [S/N removed], ETT: 2472.3, ETSO: 99.5

DURING ROUTINE MX LYCOMING SB388C (EXHAUST VALVE GUIDE INSPECTION) FOUND ALL LIFTERS P/N 15B26066, TAPPET SOCKETS P/N 15B21319, ROCKER ARMS P/N 17F19357, PUSH RODS P/N 15F28835-30 & PUSH RODS P/N 15F28835-29 TO HAVE MECHANICAL DAMAGE "HEAVY SCUFF - SCORING". LYCOMING FACTORY OVERHAULED ENGINE: O-360-J2A, [S/N removed]

ENGINE STOP UNCOMMANDED WHILE TAXIING BACK TO MY HANGAR AT MY HOME AIRPORT. DISCOVERED AFTER REMOVING ACCESSORY CASE THAT THE IDLER GEAR BRONZE BUSHING FELL OUT AND CRANKSHAFT GEAR PIN/DOWEL WAS SHEARED OFF AND CRANKSHAFT GEAR AND BOLT WERE LOOSE AND THE TAB OF THE BOLT'S LOCKPLATE AEL18639 WAS BROKEN OFF.