AA-1Yankee · Trainer · Lynx

Parts most often named Seal (1) · Engine (1) · Oil Pump (1) · Line (1)

FOUND CRANKSHAFT SEAL PUSHED FREE FROM ITS MOUNTING AREA. SEAL APPEARED DRY ROTTED AND INSTALLED WITH INSUFFICIENT SEALANT. INSTALLED NEW SEAS IAW SRM. INSPECTED OIL SCREEN AND TOOK OIL SAMPLE. NO METAL FOUND SEAL SHOULD BE INSPECTED FOR PROPER MOUNTING EVERY 100 HOURS.

ANNUAL INSPECTION RECORD CHECK FOUND AD 75-08-09 C/W NOV 1976. REPLACED GEARS 6-7-78. ENGINE OVERHAULED, NO DETAILS GIVEN. 6-30-79 - ENGINE REMOVED AND STORED. TT 697.4 HOURS. 6-30-84. ENGINE INSTALLED IN [tail no. removed]. AD 81-18-04R2. SIGNED OFF ON AD LIST AS DUE AT 2,000 HRS OR OVERHAUL. IN C/W AD 96-09-10, ENGINE REMOVED AND GEARS INSPECTED AND FOUND TO BE SINTERED IRON. BOTH GEARS REPLACED WITH HARDENED STEEL.

DURING ANNUAL INSPECTION, COULD NOT FIND VALID SIGN-OFF FOR AD 81-18-04 OR AD 96-09-10 (OIL PUMP AD). PARTS NOTIFICATION NR 96-083 DATED 5-5-97. NO PAPER WORK FOR RETURNING PARTS TO [S/N removed] (YELLOW TAGS) OR AD COMPLIANCE WAS FOUND. ENGINE WAS TORN DOWN AND INSPECTED AND NORMAL PARTS CERTIFIED AND YELLOW TAGGED. OIL PUMP AD WAS FOUND NOT TO BE DONE. C/W AD NOTE AND ASSEMBLY) ENGINE AND TEST FLEW AIRCRAFT. NO OTHER PROBLEMS FOUND WITH THE ENGINE.

Parts most often named Cylinder (1) · Pipe (1)

AIRCRAFT ENGINE, WHILE IN-FLIGHT, SUFFERED BARREL-TO-HEAD SEPARATION. SUSPECT CAUSE SEVERE METAL FATIGUE FROM WELDING MULTIPLE TIMES AND POSSIBLE IMPROPER WELDING PRACTICES AND MULTIPLE HEAT CYCLES. LYCOMING DOES NOT MANUFACTURE NEW CYLINDERS FOR THIS ENGINE. IF THEY DID, THIS WOULD NOT CONTINUE TO HAPPEN. SUBMITTER RECOMMENDS LYCOMING BE FORCED TO SUPPORT THE O-235C [S/N removed] ENGINE. ALSO, MORE CAREFUL INSPECTION OF BARREL-TO-HEAD AREAS BY MAINTENANCE PERSONNEL AND OPERATORS.

DURING ANNUAL INSPECTION, FOUND FUEL STAINS AT NR 3 CYLINDER. REMOVED NR 3 CYLINDER INTAKE PIPE AND FOUND PIPE FLANGE CRACKED ONE-THIRD AROUND TOP. THIS MAY BE CRACKED BY IMPROPER SEAT OR AGE. NEW PIPE INSTALLED THAT HAD A THICKER FLANGE. TOTAL TIME, 1,806.6 HOURS.

Parts most often named Float (1) · Carburetor (1)

ENGINE STALLED WHILE AIRCRAFT WAS ON FINAL APPROACH. DURING TEST RUN, ENGINE PERFORMED NORMALLY DURING RUN UP CHECK, IDLE CHECK AND MIXTURE CHECK AT 1000 RPM. HOWEVER, WHEN THE ENGINE LT AT IDLE (650 RPM) THE ENGINE WOULD BEGIN TO RUN RICH, LOPE AND QUIT RUNNING AFTER ABOUT 1 TO 2 MINUTES. THE CARBURETOR WAS REMOVED AND INSPECTED. ONE HALF OF THE FLOAT, WHICH IS MADE OF HOLLOW PLASTIC, WAS FILLED WITH FUEL.

Parts most often named Gasket (1)

REPLACED VAC/PUMP OIL SEAL STD-208 AND GASKET SL-61183 (2 TIMES SL-61183). OIL WOULD LEAK OUT IN GREAT AMOUNT. SEAL/GASKET DOES NOT HOLD OIL PRESSURE. THE ALUM/BODY HAD A SHAFT AND GEAR DRIVING THE VAC/PUMP. THERE IS A BORED/HOLE TO FEED OIL UNDER PRESSURE TO THE SHAFT. (X)

Parts most often named Wheel (1)

OWNER/PILOT INSTALLED NEW TIRES AS PREVENTATIVE MAINTENANCE. WHILE INSTALLING NEW TIRES, HE NOTICED THE WHEEL ASSY THROUGH-BOLTS WERE BADLY RUSTED . HE WENT TO LOCAL HARDWARE STORE, PURCHASED COMMON STEEL/GALVANIZED PLATED BOLTS AND REPLACED ORIGINAL 'AN' CADMIUM PLATED BOLTS. DURING SUBSEQUENT ANNUAL INSPECTION, FOUND THESE BOLTS AND REPLACED THEM WITH 'AN' BOLTS OF CORRECT SIZE. THE ZINC PLATED BOLTS WERE BADLY CORRODED AND THE WHEEL HALVES WERE ALSO CORRODED. CLEANED AND TREATED CORROSION.

Parts most often named Arm (1)

PILOT REPORTED TAIL WHEEL SHIMMEY ON ROLLOUT, THEN, AIRCRAFT GROUND LOOPED TO LEFT. RIGHT SIDE OF ARM ASSEMBLY P/N A-504 HAD BROKEN OFF APPROXIMATELY 1 INCH FROM CENTER OF ARM. BROKEN ENDS SHOW SIGNS OF POSSIBLE CORROSION. MAINTENANCE RECORDS NOT AVAILABLE TO DETERMINE PART TIME IN [S/N removed] OR C/W ANY STC FOR TAIL WHEEL CONVERSION.

Parts most often named Bracket (1)

(CAN) PILOT SEAT TILLED TO LEFT. FOUND FORWARD OUTBOARD ATTACH FLANGE BROKE AWAY FROM THE BRACKET.NEW BRACKET INSTALLED.

Parts most often named Support (1)

Parts most often named Valve (1)

CARBURETOR HEAT VALVE BROKEN AND PARTIALLY JAMMED. SHAFT ROTATING NORMALLY. NO HEAT GETTING TO CARBURETOR BRACKET. FILTER NOT REPLACED SINCE 1991, OVER 400 HOURS. SUBMITTER SUGGESTS NEOPRENE GASKET IS A POOR DESIGN FOR GRUMMAN AA-1C AIRBOX, VERY LITTLE OF THE GASKET IS SANDWICHED AT THE LOWER LIP.

Parts most often named Gear (1)

REMOVE VACUUM PUMP DRIVE SHAFT GEAR, OIL LEAKING INTO VACUUM PUMP, WORN SPOT ON SHAFT DAMAGED OIL SEAL CAUSING OIL LEAK.