FranklinFranklin 4A, 6A and 6V

Parts most often named Crankshaft (6) · Gear (2) · Bearing (1) · Piston (1)

UPON DISASSEMBLY IT WAS DETERMINED CRANKSHAFT TO CAMSHAFT GEAR 17725 FAILED, IT APPEARS IT WAS IMPROPERLY INSTALLED AT OVERHAUL THE GEAR HAS INDICATIONS OF MOVING FREELY ON CRANKSHAFT CAUSING WEAR AND FAILURE.

DURING CRUISE FLIGHT THERE WAS AN INTERNAL ENGINE FAILURE RESULTING AN A CRACKED ENGINE CASE AND EMERGENCY LANDING. THE ENGINE WAS RETURNED FOR OVERHAUL.

ON A FLIGHT THE ENGINE STOPPED SUDDENLY WITH NO WARNING. THE AIRCRAFT LANDED. THE ENGINE ACCESSORY CASE HAD MAJOR DAMAGE. THE MAGNETOS WERE BROKEN AWAY FROM THE CASE AND THERE WERE SOME LARGE HOLES IN THE CASE. A TEARDOWN INSPECTION REVEALED THAT THE CRANKCASE GEAR WAS FRACTURED IN SEVERAL PIECES. NOT ALL OF THE PIECES WERE FOUND.

Parts most often named Washer (2) · Exhaust Valve (2) · Rocker Arm (1) · Piston (1)

THE NR 3 CYLINDER ROCKER ARM SHAFT FAILED (BROKE) AT THE CENTER SUPPORT POSITION. ADDITIONALLY, (2) OF THE (3) ROCKER ARM BOSS SECURING BOLTS FAILED AND THE THIRD BOLT PULL OUT OF THE HEAD.

DURING CRUISE ENGINE STARTED RUNNING. ROUGH AND LOST POWER. AIRCRAFT MADE EMERGENCY LANDING IN CORN FIELD. FOUND EXHAUST VALVE NR 4 ENGINE CYLINDER MISSING AND HOLE IN PISTON HEAD. (.5 INCH X 2.5 INCH) HOLE.

SEVERE ENGINE ROUGHNESS OCCURRED WHILE IN FLIGHT. AN OFF AIRPORT LANDING WAS MADE WITH NO DAMAGE TO AIRCRAFT AND NO INJURIES. NR 1 CYLINDER FOUND TO HAVE NO COMPRESSION. FOUND THAT PN 17726 VALVE SPRING WASHER HAD FAILED ALLOWING INTAKE VALVE TO DROP INTO CYLINDER NR 1. ENGINE TSMOH 1106. TSO 418.45. UNABLE TO DETERMINE IF PART WAS REPLACED AT MAJOR OVERHAUL OR TOP OVERHAUL.

Parts most often named Engine (3)

EXPERIENCED LOSS OF ENG POWER. ATTEMPTED TO RESOLVE ENG PROBLEM, CHECKED CARB HEAT, FUEL VALVE, LT AND RT MAGS, THROTTLE, NO SUCCESS. ENG WOULD ATTEMPT TO RUN OCCASIONALLY FIRING ON CYLINDERS. FULL FUEL ON BOARD. (K)

ENGINE SHUT DOWN ON CLIMB OUT AT APPROX. 80 FEET, ALTITUDE. VISUAL EXAMINATION REVEALED NO OBVIOUS REASON FOR THE FAILURE. FUEL VENTING AND QUANTITY WERE COMPROMISED BY THE CRASH IMPACT AFTER RECOVERY EFFORTS WERE COMPLETE FUEL WAS PUT IN THE RIGHT WING TANK AND THE ENGINE WAS EASILY STARTED AND RAN WITH NO MALFUNCTIONS.

Parts most often named Id Plate (1) · Placard (1) · Venturi (1)

IDENTIFICATION STICKER CAME LOOSE AND LODGED AGAINST CARBURETOR VENTURI. STICKER WAS STUCK IN CARBURETOR HEAT BOX AND WAS NOT SEEN WHEN NEW FILTER WAS INSTALLED. AS A RESULT, ACFT LOST ENGINE POWER AND LANDED ON JEFERSON BLVD IN W. SAC. SUBMITTER RECOMMENDED THAT IDENTIFICATION OF FILTER BE STAMPED ON OR ETCHED. (X)

PILOT COMPLAINT, ENGINE RUNNING VERY RICH. DISASSEMBLED CARBURETOR, FOUND FLOAT LEVEL TOO HIGH AND TWO-PIECE VENTURI INSTALLED. TWO OF THE THREE LEG CLIPS WERE MISSING AND VENTURI WAS LOOSE. SUBMITTER STATED AD 63-22-03 IS NOT CLEAR. DOES NOT INCLUDE THESE [S/N removed] ENGINES WHICH IT SHOULD. MARVEL-SCHEBLER BULLETIN A4-63 STATES ALL MA4-5 CARBURETORS. SUBMITTER STATED AD 63-22-03 SHOULD HAVE ALL ENGINE REFERENCES DELETED AND JUST SAY ALL MA4-5 CARBS. THIS IS A SAFETY OF FLIGHT ITEM.

Parts most often named Gear (2) · Capacitor (1)

FOLLOWING TAKEOFF, AT ABOUT 200 FT, ENGINE FAILED. AIRCRAFT LANDED IN FIELD WITHOUT FURTHER INCIDENT. SUBSEQUENT INSPECTION REVEALED CAM GEAR, WHICH DRIVE BOTH MAGNETO GEARS, HAD SHATTERED. CAM GEAR IS MADE OF MICARTA (FIBER) MATERIAL.

AIRCRAFT LANDED AT REMOTE FIELD LOCATION ON ISLAND. SEVERAL HOURS LATER, AIRCRAFT STARTED. RIGHT MAGNETO COMPLETELY FAILED. ON RPM MAG CHECK, MAGNETO REMOVED AND TAKEN APART. NYLON DISTRIBUTOR GEAR LOST 3 TEETH. GEAR USED WAS NOT NEW, CHECKED WITH TELEDYNE CONTINENTAL. THEY CONFIRMED DISTRIBUTOR GEARS ARE ROUTINELY REUSED. SINCE THERE IS NO WAY TO ZYGLO OR MAGNAFLUX NYLON DISTRIBUTOR GEARS, SUBMITTER RECOMMENDED ROUTINE REPLACEMENT OF ALL DISTRIBUTOR GEARS AT FACTORY OVERHAUL. (X)

WHEN RT MAG SELECTED DURING ENGINE RUN-UP CHECK, ENGINE FAILED. OBSERVED EXCESSIVE SPARKING AND POINT WEAR (7 HRS SINCE NEW). ENGINE RAN NORMALLY AFTER REPLACEMENT OF CAPACITOR AND POINT ADJUSTMENT. SUSPECT MANUFACTURING DEFECT OF PMA CAPACITOR.

Parts most often named Spinner (1)

ON CLIMBOUT A VIBRATION DEVELOPED THAT CONTINUED TO INCREASE IN AMPLITUDE. THE FLIGHT WAS ABORTED. SUBSEQUENT INVESTIGATION REVEALED THAT THE FORWARD PLASTIC SPINNER BULKHEAD HAD FAILED AROUND ITS PERIPHERY ALLOWING THE SPINNER TO WOBBLE. CONTINUED OPERATION IN THIS CONDITION WOULD HAVE RESULTED IN FAILURE OF THE AFT BULKHEAD AND DEPARTURE OF THE SPINNER FROM THE AIRCRAFT.

Parts most often named Nut (1)

Parts most often named Hub (1)

Parts most often named Starter (1)

Parts most often named Collar (1)

PROBLEM REPORTED: PROP WOULD NOT CYCLE W/WARM ENGINE OIL. DISASSEMBLED ENGINE AND FOUND ONE SOCKET HAS SCREW .1562 THAT HOLDS THE TRANSFER COLLAR TOGETHER BROKEN ALLOWING THE COLLAR AND SEALS TO BECOME LOOSE ON CRANKSHAFT OIL TO ESCAPE AND NOT ALL TO THE PROPELLER. NO IMPROPER REPAIR, PREVIOUS ACTIONS.