PA-18Super Cub

Parts most often named Fuel Tank (7) · Fuel Cap (1) · Tank (1)

LT WING TANK AT 157 HRS SEAM WELD BROKE OPEN WHILE SITTING ON GROUND CAUSING FUEL LEAK INTO WING. WELDS EVALUATED FOUND TO BE THIN AND OF POOR QUALITY.

LT FUEL TANK WAS LEAKING. PILOT ADVISED US OF LEAK. WE DRAINED BOTH TANKS AND TURNED THEM INTO REP. THEY ADVISED US THERE WAS AS/L ON BOTH TANKS. WERE REMOVED AND SENT IN TO MFG FOR REPAIR AND APPROVAL. (K)

CRACK WAS FOUND ALONG THE LOWER SEAM ON THE INBOARD SIDE. APPLICATION 180HP FLOAT PLANE. INSUFFICIENT AMOUNT OF MATERIAL ALONG WELDED SEAMS.

Parts most often named Carburetor (4) · Screw (1) · Float (1) · Throttle Body (1)

THE CARBURETOR WAS REBUILT AND YELLOW TAGGED. FLOAT LEVEL WAS SET AT 9/32 INSTEAD OF THE REQUIRED 7/32 CAUSING A LEAN CONDITION THAT BURNED THE TOP END OFF THE MOTOR.

ENGINE RAN POORLY ON CLIMB FROM BANNER PICK UP - ABOUT 1200 FT AGL ENGINE ONLY PRODUCED 100 RPM WITH BLACK SMOKE COMING FROM EXHAUST STACKS. NR 2D, NR 4 SPARK PLUGS WERE BLACK WITH SOOT. IT WAS DETERMINED THAT THE CARBURETOR WAS NOT FUCTIONING PROPERLY. R/P CARBURETOR WITH MA4SPR-10-3678-32, [S/N removed] KAE 07064. ENGINE HAS RUN FINE SINCE CARBURETOR INSTALLATION.

(CAN) DURING GROUND RUN UP PRIOR TO ANNUAL INSPECTION, ENGINE OBTAINED A MAXIMUM RPM OF 1900. INSPECTION FOUND CARBURETOR THROTTLE BODY SCREWS LOOSE AND FUEL STAINS ON BOWL. CARBURETOR REMOVED AND FORWARDED TO REPAIR FACILITY. (TC N 20080226001)

Parts most often named Exhaust Valve (2) · Cylinder (2) · Valve Seat (1) · Rocker Boss (1)

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.

ORIGINAL INSTALL DATE 8-28-2023. NEW CYLINDERS REMOVED AT 434HRS BY MECHANIC DUE TO RING FLUTTER, RING CHATTER, WASHBOARDING. INCONSISTENT METAL WEAR PATTERN ON THE NITRIDE BORE. DISCOVERED BY BORESCOPE AT 100HR INSPECTION. MANUFACTURER REPLACED CYLINDERS WITH NEW. REPLACEMENT CYLINDERS HAD LYCOMING COMPRESSION RINGS INSTEAD OF SUPERIOR. OIL RING WAS STILL SUPERIOR. P/N SL 36006W-A20P, S/N´S 366W00 000 6027, 366W00 000 6029, 366W00 000 6016, 366W00 000 6030.

ENGINE WAS DISASSEMBLED AND INSPECTED FOR PROP STRIKE INSPECTION. DURING TEST CELL OPERATION THE TECHNICIAN NOTICED AN OIL LEAK AT THE NR4 CYLINDER. FURTHER INSPECTION REVEALED THAT THE PUSH ROD TUBE RETAINER BROKE INSIDE THE ROCKER COVER CAUSING THE TUBE AND SEAL TO FALL OUT OF POSITION.

Parts most often named Crankshaft (2) · Piston Ring (1) · Shaft (1) · Stud (1)

DURING TAKE OFF, WITH GLIDER IN TOW, AIRCRAFT EXPERIENCED AN UNCOMMANDED ENGINE SHUT DOWN. INVESTIGATION REVEALED THAT THE NR 3 PISTON RINGS WERE NOT INSTALLED PROPERLY.

AIRCRAFT SUFFERED CATASTROPHIC ENGINE SEIZURE. MADE SUCCESSFUL GOLF COURSE LANDING. ENGINE DISASSEMBLY RECEIVED BROKEN CRANKSHAFT AT THE FORWARD SIDE OF NR 4 ROD JOURNAL.

Parts most often named Elt (3) · G Switch (1) · Battery Pack (1)

ELT REMOTE WOULD NOT ACTIVATE. ELT LIGHT WOULD COME ON BUT DID NOT TRANSMIT. INSTALLED IN AC FOR LESS THAN 4 YEARS. (K)

FUNCTION TESTED ELT AS PART OF ROUTINE INSPECTION OF AIRCRAFT. FIVE MINUTES AFTER TEST, ELT WAS WARM TO TOUCH. REMOVED BATTERY PACK, ESTIMATED TEMPERATURE TO BE 130 DEGREES FAHRENHEIT. WIRES NOT TOUCHING, STAYED WARM FOR 15 MINUTES. NEW BATTERY PACK IN ELT CHECKED GOOD, DID NOT OVERHEAT.

Parts most often named Pipe (1) · Flange (1) · Muffler (1) · Stack (1)

LEADING EDGE EXHAUST SYSTEM INSTALLED BY STC SA02200AK FAILED AT THE SAIL PIPE TO MUFFLER WELD. SYSTEM HAS 36 HOURS SINCE NEW. (K)

FOUND WELD ON WYE PIPE CRACKED AT ANNUAL INSPECTION. (NO PARTS AVAILABLE AT THIS TIME) ALSO FOUND INNER BAFFLE ON SAME PIPE CRACKED.

A LOUD KNOCKING SOUND EMANATED FROM THE ENGINE COMPARTMENT. SHORTLY AFTER, ENGINE BEGAN TO EXPERIENCE SEVERE VIBRATION AND LOSS OF POWER. THE RAM DROPPED TO 1,100 DEGREES, OIL AND FUEL PRESSURE REMAINED NORMAL. BUT AIRCRAFT CONTINUED TO LOSE POWER AND ALITITUDE. THE INSPECTION OF THE ENGINE REVEALED NR 3 EXHAUST STACK MOUNTING FLANGE AND SEVERAL STUDS WERE BROKEN. EACH CYLINDER HAD NORMAL COMPRESSION AND THE ENGINE OIL SHOWED OBVIOUS SIGNS OF METALIC PARTICLES.

Parts most often named Muffler (4) · Baffle (1)

ENGINE EXHAUST TAIL PIPE FAILED AT THE MUFFLER WELD. WITH 36 HOURS TOTAL TIME SINCE NEW. LEADING EDGE EXHAUST SYSTEM WAS INSTALLED BY STC SA02200AK.

THE TAILPIPE CRACKED AWAY FROM THE SHELL. THERE ARE NO STRAPS WELDED FROM THE PIPE TO THE SHELL LIKE SOME OTHER MUFFLERS. THE METAL FAILED, NOT THE WELD.

DURING ANNUAL INSP FOUND CRACK AT END OF ONE SUPPORT BRACE WITH EVIDENCE OF EXHAUST LEAK. ADVISED OWNER, HE SAID HE HAD EXPERIENCED EXHAUST LEAKAGE WITH MILD NOSE AND LEAKAGE. REPAIRED MUFFLER AND RETURNED TO US AND MUFFLER WAS REINSTALLED. (K)

Parts most often named Bushing (2) · Rotor (1) · Impulse Coupling (1)

(CAN) DURING PREFLIGHT RUNUP A HIGH RPM DROP OFF WAS REPORT ON LT MAGNETO. NOT IMPULSE COUPLING ENGAGEMENT WAS NOTED DURING MAINTENANCE INSPECTION. UPON REMOVAL OF DEFECTIVE MAGNETO, THE IMPULSE COUPLING WAS OBSERVED TO BE NON FUNCTIONING AND MAGENTO DRIVE GEAR COULD BE ROTATED WITH A LAG OF ROTATION OF POINTS CAM FOLLOWER. MAGNETO HAD 50 HRS SINCE IMPULSE COUPLING AD AND 500 HR. INSPECTION COMPLIANCE. MAGNETO BEING SHIPPED BACK TO O/H FACILITY TO INVESTIGATE FAILURE.

PILOT NOTICED LACK OF POWER AND ROUGHNESS AFTER TAKEOFF. RETURNED TO FIELD, DISCOVERED INOPERATIVE RT MAGNETO. DISASSEMBLY OF RT MAGNETO REVEALED ROTOR SHAFT HAD SHEARED FLUSH WITH BOTTOM OF CAM CUTOUT. THE REMAINING ROTOR AND DISTRIBUTOR BOTH ROTATED FREELY. NO EVIDENCE OF PROBLEMS WITH EITHER GEAR. PROBABLE CAUSE IS A DEFECT IN MFG (POSSIBLY BAD METAL OR STRESS CRACK FROM MACHINING CAM SLOT. (K)

ENGINE IS FACTORY REMANUFACTURED 2-11-98. MAGNETO GOOD, PREVIOUSLY WOULD NOT START, NEXT FLIGHT. BRASS BUSHING IS DISTRIBUTOR BLOCK WORN BADLY.

Parts most often named Bellcrank (3) · Flap System (1)

DURING SCHEDULED INSP, FOUND THAT WITH THE FLAPS EXTENDED INTO ANY POSITION OTHER THAN FULLY RETRACTED, WILL WITH A MINOR LOAD CAUSE THE OPPOSITE FLAP TO GO ASSYMETRIC. IF THE RT FLAP IS PUSHED UP, THE LT WILL DUMP COMPLETELY DOWN AND VISA VERSA. ACFT KIT MFG CONTACTED AND REPLIED THAT THIS DOES NOT OCCUR. CONSTRUCTION MANUAL OBTAINED AND DETERMINED THAT THIS PROBLEM IS A DESIGN FAULT. MFG WILL NO LONGER RETURN CALLS.

WHILE COMPLETELY DISASSEMBLING FOR RECOVERY, FOUND BOTH BELLCRANKS CRACKED. ONLY WAY TO SEE IS WITH MIRROR OR COMPLETE DISSASSEMBLE. BOTTOM OF BELLCRANK NOT CRACKED.

Parts most often named Valve (1) · Hose (1) · Control Cable (1) · Air Box (1)

CARBURATOR AIR BOX AIR FILTER RETAINING SHAFT SHEARED ADJACENT TO FISH MOUNTH WELD AT FORWARD EDGE OF HORIZONTAL PLATE (APPROXIMATELY 1/3 SHAFT LENGTH FROM BASE). AIR FILTER DOME, SHAFT AND RETAINING NUT APPEARANTLY DEPARTED AIRPLANE IN FLIGHT. AIR FILTER WAS FOUND LOOSE IN COWL AIR SCOOP AFTER LANDING. NO OPERATIONAL INDICATIONS AND NO DAMAGE TO PROPELLER, COWL, FUSELAGE OR LANDING GEAR. AIRPLANE COMPLETELY REBUILT 2004. NEW K & N AIR FILTER INSTALLED AT ANNUAL INSPECTION NOVEMBER 2006. PHOTOS AVAILABLE.

CARBURETOR HEAT CABLE COULD HAVE POSSIBLY CONTRIBUTED TO ACCIDENT. DURING INVESTIGATION, CABLE WAS FOUND DETACHED; APPARENTLY IT HAD BROKEN PRIOR TO OR AS A RESULT OF THE ACCIDENT.

ENGINE STOPPAGE AND FORCED LANDING OFF AIRPORT OCCURRED WHEN THE BUTTERFLY VALVE IN THE CARBURETOR HEAT AIRBOX SEPARATED FROM ITS SHAFT AND BLOCKED OFF AIR FLOW TO CARBURETOR/ENGINE.