269/​300Schweizer · Hughes

Parts most often named Drive Belt (3) · Clutch Cable (2) · Idler Pulley (2) · Control Unit (1)

(CAN) DRIVE BELT AXIAL SPLIT OVER 50 PERCENT OF BELT CIRCUMFERENCE; SPLIT OCCURS UNDER OUTER LAYER OF BELT. NOTE: PLEASE ADVISE IF PHYSICAL VERIFICATION IS REQUIRED AS MUST RETURN BELTS TO MFR FOR WARRANTY CONSIDERATION. (TC NR 20070612004)

ONE OF THE TWO BELT DRIVE CLUTCH ACTUATOR CABLE PULLEY BRACKETS BROKE CLEAN ACROSS BETWEEN THE FRAME MOUNT HOLE AND THE PULLEY MOUNT HOLE DURING ENGAGEMENT OF THE ROTOR SYSTEM. DURING THE SUBSEQUENT TAKE OFF ATTEMPT THE ROTOR RPM WOULD BLEED OFF RAPIDLY DUE TO DRIVE BELT SLIPPAGE ANY TIME THE M/R COLLECTIVE CONTROL WAS RAISED.THE AICRAFT WAS SHUT DOWN AND THE PROBLEM INVESTIGATED BY THE OPERATOR THEN MAINTENANCE PERSONELL WERE NOTIFIED.

(CAN) OIL LEAKING FROM FREEWHEEL WAS NOTED AT REFUELING STOP. NUT (WHICH IS ALSO SEAL RUNNER) WAS FOUND LOOSE. NUT WAS RETORQUED AND FLUSH OF FREEWHEEL PRODUCED NO DISCOLORATION OR PARTICLES. LEAK CHECK CARRIED OUT AND RETURNED TO [S/N removed]. NOTE: THAT OIL ONLY LEAKED OUT AFTER SHUTDOWN (NO OIL SPRAY). THEREFORE, IN THIS INSTANCE, THE OIL WAS DYNAMICALLY HELD IN, EVEN WITH THE LACK OF SEALING AT FRONT.

Parts most often named Magneto (5) · Bearing (4) · Adapter (3) · Booster (1)

DURING 25 HOUR INSPECTION, OIL WAS DRAINED FROM ENGINE AND FOUND BEARING CAGE BALL RETAINER MADE OF PLASTIC (KIND OF) ON ENGINE OIL SCREEN. REMOVED BOTH MAGNETO DRIVE ADAPTER ASSEMBLY AND FOUND THE PROBLEM ON THE RT ADAPTER (BALL RETAINERS MISSING). REPLACED THE PART P/N LW15416.

(CAN) SMALL METAL FRAGMENT DISCOVERED WHILE CHANGING ENGINE OIL. FOUND TO BE PART OF A BEARING KEEPER IN RT MAGNETO ADAPTER BEARINGS. THIS IS THE SECOND TIME THIS PROBLEM HAS OCCURRED ON THIS AIRCRAFT. (TC NR 20060213005)

MAGNETO OVERHAULED, WAS FOUND TO HAVE A LOOSE ROTOR TAB THAT CHEWED UP THE DISTRIBUTOR BLOCK TERMINALS. ALSO AN INNER BEARING RACE WAS LOOSE AND SCORED THE SHAFT AND AN OUTER BEARING RACE WAS LOOSE IN THE CASE AND THE CASE WAS THEREFORE JUNK.

Parts most often named Plug (7) · Camshaft (2) · Seal (2) · Bearing (2)

NORMAL TAKEOFF, HOVER, AND STEADY LEVEL FLIGHT. 30 MINUTES ENROUTE, SUDDEN VIBRATIONS FOLLOWED BY LOW RPM WARNING LIGHT & HORN. VERIFIED DROPPING NEEDLES AND LOWERED COLLECTIVE FOR AUTOROTATION. CHECKING AIRSPEED GAUGE AT 40KTS, ADJUSTED FORWARD CYCLIC FOR MORE AIRSPEED. VIBRATIONS STOPPED AND ENGINE QUIT. ESTABLISHED AUTOROTATION, LOOKED FOR LANDING SPOT, AIRSPEED 60-70KTS, FLARED AND LANDED. UPON VISUAL INSPECTION OF ENGINE, CATASTROPHIC FAILURE OF NR 4 CYLINDER, PISTON.

(AUS) ENGINE CRANKSHAFT SEAL LEAKING. INVESTIGATION FOUND SEAL HAD DISINTEGRATED AROUND THE SEALING LIP. THIS IS A REPLACEMENT SEAL AFTER THE SEAL FAILURE IN MDR 04/0084.

AT 25 HOUR OIL CHANGE, FOUND METAL PARTICLES IN SUCTION SCREEN AND FILTER. ON INSPECTION, FOUND NR 2 MAIN BEARING HAD SPUN NEARLY CAUSING ENGINE FAILURE. CHECK SCREENS.

Parts most often named Cylinder (7) · Cylinder Head (2) · Intake Valve (2) · Line (1)

2 NR CYLINDER HEAD ASSEMBLY APPEARS TO HAVE FAILED DURING FLIGHT RESULTING IN A SEVERE ENGINE VIBRATION AND A FORCED LANDING. EXAMINATION OF UPPER HALF OF FAILED CYLINDER ASSEMBLY REVEALS THAT A CRACK OCCURRED AND PROPAGATED SYMMETRICALLY AROUND THE CYLINDER APPROXIMATELY .3750 BENEATH WHERE THE CYLINDER BARREL MEETS THE CYLINDER HEAD. NO INTERNAL CYLINDER /PISTON DAMAGE WAS VISUALLY OBSERVED.

(CAN) EXHAUST VALVE ON NR 2 CYL STUCK CAUSING LOSS OF ENG PWR. ACFT DESCENDED INTO A FIELD. THE HELICOPTER WAS TAKEN BY TRUCK TO MX FACILITY TO DETERMINE PROBLEM. ENGINE MFG WARRANTIED REPAIR OF CYLINDER AND VALVE ASSY.

DURING 100HR COMPRESSION CHECK, AIR WAS FOUND TO BE LEAKING AROUND TOP SPARK PLUG AREA. FURTHER INSPECTION NOTED CRACK ALONG TOP COOLING FIN AREA. UPON REMOVING CYLINDER, CRACK WAS FOUND TO RUN FROM AREA AROUND TOP SPARKPLUG HOLE THROUGH EXHAUST SEAT AND THROUGH TO EXHAUST FLANGE MOUNTING STUD.

Parts most often named Shaft (5) · Pinion Gear (2) · Gear Tooth (2) · Bearing (2)

DURING SHUT-DOWN, PILOTS REPORTED CLUNKING NOISE. UPON FURTHER INSPECTION, NOISE WAS LOCATED AT UPPER PULLEY SPRAG CLUTCH AREA. REMOVED UPPER PULLEY AND FOUND M/R TRANSMISSION INPUT PINION (PN:269A5103-51) WORN EXCESSIVELY DUE TO LOOSE AFT PINION NUT. PROBABLE CAUSE OF AFT PINION NUT LOOSENING IS SB DB-019 (CORROSION PROTECTION OF INPUT PINION SPLINES). POSSIBLE EXCESSIVE APPLICATION OF ZINC-CHROMATE PRIMER TO INPUT PINION CAUSED IMPROPER CLAMP-UP DURING TORQUING PROCEDURE. (K)

DURING 600 HOUR INSPECTION GREASE IN LOWER PULLEY SHAFT HAD A RUSTY (BROWN) COLOR (NOTE: ANDEROL GREASE IS BLACK). UPON INSPECTION PART HAS 600.0 HOURS SINCE NEW, THE SPLINES SHOWED IRREGULAR WEAR. SPECULATION OF MFG AND OUR FACILITY IS THAT THE GREASE WAS CONTAMINATED. FIRST 600 HOUR INSPECTION ON THIS AC, SAME GREASE SINCE DELIVERY FROM MFG. (K)

(AUS) MAIN TRANSMISSION TAIL ROTOR DRIVESHAFT PINION FAILED IN AREA LOCATED JUST IN FRONT OF THE THREADED AREA ALLOWING THE TAIL ROTOR DRIVE TO SEPARATE. AIRCRAFT STRUCK THE GROUND CAUSING EXTENSIVE DAMAGE TO THE LANDING GEAR.

Parts most often named Carburetor (8) · Fuel Control (2) · Float (1) · Check Valve (1)

(AUS) ENGINE FUEL CONTROL UNIT FAULTY. INVESTIGATION FOUND PRESSURE ON THE MIXTURE ARM CHANGED THE FUEL FLOW RATE CAUSING THE ENGINE TO STOP.

AIRCRAFT EXPERIENCED A PARTIAL POWER FAILURE ALONG WITH A SUDDEN VIBRATION. DURING THE SUBSEQUENT INSPECTION, THE ACCELERATOR PUMP DISCHARGE CHECK VALVE IN THE CARBURETOR WAS FOUND TO HAVE BACKED OUT OF ITS CHAMBER. RECOMMEND REDESIGNING ALL THE CHECK-VALVES AND JETS IN THE CARBURETOR TO INCORPORATE A PERMANENT NYLON THREAD LOCK IN THE THREADS.

(CAN) ENGINE QUIT DURING IDLE , AFTER RESTART, ENGINE WOULD NOT ACCELERATE FROM IDLE TO WARM UP RPM. CARBURETOR REPLACED.

Parts most often named Bearing (5) · Damper (1) · Bushing (1) · Ring (1)

(AUS) MAIN ROTOR GRIP BLADE BOLT BUSHES INCORRECTLY FITTED ON ALL THREE GRIPS. THE BUSHES WERE FITTED UPSIDE DOWN LEAVING A GAP BETWEEN THE GRIPS AND THE BLADES. WHEN THE BLADE BOLTS WERE TIGHTENED,THE GRIPS WERE DISTORTED.

(AUS) MAIN ROTOR ELASTOMERIC DAMPERS FAULTY. AIRCRAFT HAD SUFFERED A HARD LANDING/SUDDEN STOPPAGE APPROXIMATELY 150 HOURS PREVIOUSLY.INSPECTION THEN FOUND NIL DEFECTS BUT SINCE THAT TIME THE AIRCRAFT HAD DEVELOPED A VIBRATION AND AN INSPECTION HAD FOUND ONE DAMPER DELAMINATED AND ONE DAMPER OUT OF LIMITS. THE THIRD DAMPER FAILED THE LOAD/STRETCH TEST.

DURING AN ANNUAL INSPECTION, DISCOVERED THE DROOP STOP RING WAS PREVIOUSLY INSTALLED INVERTED. THE MAIN ROTOR HEAD WAS ASSEMBLED THREE YEARS AND 60 HOURS PRIOR TO THIS INSPECTION.

Parts most often named Tube (3) · Support (2) · Mast (1) · Lockwasher (1)

TUBE APPEARED TO HAVE A PAINT FLAW. REMOVAL OF PAINT REVEALED A CRACKED TUBE WELD. TUBE REMOVED FROM [S/N removed] FOR TESTING/ INSPECTION BY MANUFACTURER.

TUBE APPEARED TO HAVE HAD A CRACK UNDERNEATH THE LUG WELD PRIOR TO COMPLETE FAILURE. THE FAILURE OF THIS TUBE ASSEMBLY CAUSED SEVERE VIBRATION IN AIRCRAFT, RESULTING IN DAMAGE TO MAIN ROTOR BLADES, TAIL ROTOR BLADES, DRIVETRAIN, TAILBOOM AND CANOPY.

REMOVE MAIN ROTOR BLADES AND DISASSEMBLE MAIN ROTOR HUB TO GAIN ACCESS TO SWASHPLATE DISASSEMBLE, FOUND WORN LOCKWASHER, REPLACED SAME. CLEANED, INSPECTED, AND RELUBED. REASSEMBLE PREVIOUSLY REMOVED COMPONENTS.

Parts most often named Spline (1) · Shaft (1) · Bumper Block (1) · Drive Shaft (1)

(OG5S) DURING 800 HR, 12 AND 24 MONTH INSP, THE MAIN ROTOR DRIVE SHAFT WAS FOUND TO BE WORN JUST ABOVE THE MAIN ROTOR THRUST BEARING. UPON FUTHER INSP, THE WEAR WAS DETERMINED TO BE CAUSED BY THE M/R THRUST BEARING TUBE NOT BEING CHAMFERED IN THE CONTACT AREA. THIS WAS CONFIRMED BY COMPARISON WITH A NEW THRUST BEARING TUBE. MFG HAS BEEN CONTACTED AND MAIN ROTOR DRIVE SHAFT HAS BEEN SENT TO THEM FOR EVALUATION.

WHILE IN CRUISE FLIGHT, TAIL ROTOR FAILURE AT APPROX 700 FT, PILOT WENT TO FLAT PITCH, PUT HELICOPTER IN A DIVE TO AVOID ROTATION FROM TORQUE, PERFORMED FULL AUTOROTATION TO THE GROUND, NO DAMAGE TO HELICOPTER OR INJURIES TO OCCUPANTS. DRIVE GEAR ON TAIL ROTOR INPUT SHAFT STRIPPED AS WELL AS FWD GEAR ON TAIL ROTOR DRIVE SHAFT. SUSPECT POSSIBEL METAL PROBLEM. CURRENT INSPECTION IS 600 AND 1200 HOURS OR 24 MONTHS, POSSIBLY LOWERING INSPECTION INTERVALS TO SAY 300 HOURS. HELICOPTER WAS 30 HOURS FROM 1200 HR. (K)

DURING A SCHEDULED INSPECTION, THE LOWER PULLEY DRIVESHAFT WAS FOUND TO HAVE AN ABNORMAL AMOUNT OF MOVEMANT. UPON REMOVING THE SHAFT, THE CRANKSHAFT BUMPER BLOCK WAS FOUND TO BE MISSING. IT SHOULD BE NOTED THAT THIS PART IS NOT IN EITHER THE AIRFRAME OR THE ENGINE MANUFACTURERS PUBLICATIONS. THERE IS NO STEP TO INSTALL OR INSPECT FOR INSTALLATION OF THIS BUMPER IN THE ENGINE INSTALLATION PROCEDURES.

Parts most often named Alternator (2) · Bracket (2) · Pulley (1)

(CAN) ALTERNATOR FAILED ON STARTUP. FOUND ROTOR JAMMING AND PULLEY HAD OVERHEATED. LOOSE PARTS HEARD INSIDE ALTERNATOR. NO PREVIOUS INDICATIONS OF IMPENDING FAILURE. (TC NR 20070705012)

ALTERNATOR PULLEY COOLING FINS BECAME DETACHED FROM PULLEY CAUSING ALTERNATOR TO VIBRATE OFF ENGINE SHEARING BRACKET BOLTS. INSTALLED NEW BOLTS AND ALTERNATOR. PROBLEM HAS NOT RECURRED. POSSIBLE CAUSE IS FATIGUE OF COOLING FINS. SUBMITTER SUGGESTED INSPECTION OF FINS EACH 100 HOURS FOR CRACKS.