MauleM-4 through M-9

Improperly lubricated roller bearings in certain S-1200 series magnetos may cause overheating and magneto seizure. This AD requires replacement of affected magnetos or inspection and component replacement if no white grease is detected.

Engine models named IO-360, IO-540, O-235, O-320, O-360, O-470, O-540

Three crankshaft assembly failures resulted in loss of engine power and emergency landings. This AD requires immediate removal from service of all affected SAP crankshaft assemblies.

Engine models named IO-360-B1A, IO-360-B1B, IO-360-B1D, IO-360-B1E, IO-360-B1F, IO-360-B2F, IO-360-L2A, IO-360-M1A, O-360, O-360-A1A, O-360-A1C, O-360-A1D

Externally mounted fuel injector fuel lines on certain Lycoming fuel injected engines can fail, potentially causing uncontrolled engine fires and damage. This AD requires inspection and replacement if necessary of fuel injector fuel lines with proper clamping.

Engine models named IO-360-A1A, IO-360-A1B, IO-360-A1B6, IO-360-A1B6D, IO-360-A1C, IO-360-A1D, IO-360-A1D6, IO-360-A2A, IO-360-A2B, IO-360-A3B6, IO-360-A3B6D, IO-360-B1B

Propeller governor shaft set screws can come loose due to improper installation, potentially causing engine and airframe damage. This AD requires inspection and corrective action on affected Lycoming wide deck aerobatic engines equipped with front-mounted propeller governors.

Engine models named IO-540-K1K5

Certain Lycoming reciprocating engine crankshafts can fail, causing total engine power loss and in-flight engine failure. This AD requires replacement of affected crankshafts as listed in Lycoming Mandatory Service Bulletin 569A.

Engine models named IO-540, O-540

Hartzell propeller hubs may crack, causing blade separation and loss of aircraft control. The AD requires initial and repetitive eddy current inspections of the front cylinder half for cracks, removal of cracked hubs from service, or installation of improved design hub (suffix SN A or B) as terminating action.

Engine models named IO-360 series, O-360 series

TCM EQ3 cylinders have been found cracking, which can cause loss of engine power and engine fires. The AD requires visual inspections of EQ3 cylinders for cracks, with removal of all EQ3 cylinders as the terminating action.

Engine models named O-470

Certain crankshafts in Lycoming AEIO-360, IO-360, O-360, LIO-360, and LO-360 series engines can fail, causing total engine power loss and possible aircraft loss. This AD requires replacement of affected crankshafts.

Engine models named IO-360, O-360

Certain Lycoming 360 and 540 series engines have experienced crankshaft failures that could cause total engine power loss and in-flight engine failure. This AD requires replacement of affected crankshafts.

Engine models named IO-360, IO-540, O-360, O-540

Magneto impulse coupling assemblies on certain Lycoming engines can fail, potentially causing engine failure. This AD reduces the inspection interval for riveted-impulse coupling assemblies installed on specified Lycoming engine models.

Engine models named IO-540, O-540

Crankshaft gear retaining bolts may loosen or fail on certain Lycoming direct-drive reciprocating engines, potentially causing sudden engine failure. The AD requires removal of existing gear retaining bolts and lockplates from service, installation of new hardware, and inspection of crankshaft gear installation after propeller strikes, sudden stoppages, or overhaul.

Engine models named O-235, O-320 series, O-360 series, O-540

Certain crankshaft gear retaining bolts may fail, causing loss of engine power and a forced landing. This AD requires replacing the affected bolts with improved versions using approved kits.

Engine models named IO-540, O-540

Certain Textron Lycoming fuel-injected engines equipped with Crane/Lear Romec rotary fuel pumps are prone to fuel leakage from the pump relief valve, which could cause engine failure or fire. Owners must inspect pump relief valve attaching screws for proper torque and replace the affected fuel pump at or before engine overhaul with a new design pump having enhanced leak resistance.

Engine models named IO-360, IO-540

Textron Lycoming reciprocating engines have experienced crankshaft failures that can result in total engine power loss and in-flight engine failure. This AD requires replacement of suspect crankshafts that were hammer forged with press-forged crankshafts before further flight.

Engine models named IO-540

Magneto impulse coupling stop pins can migrate into the engine gear train, causing engine failure. This AD requires replacement of affected magnetos within 10 flight hours, inspection of removed magnetos to verify the stop pin is in place, and inspection of the engine gear train if the stop pin is missing.

Engine models named IO-360, O-300

Oil can leak between the converter plate and accessory housing on certain Lycoming engines, potentially causing complete engine oil loss, engine seizure, and fire. This AD requires replacement of the oil filter converter plate gasket or kit, inspection of the oil filter base for leakage, and eventually installation of an improved gasket or kit to eliminate the need for repetitive replacements.

Engine models named IO-360-A1B6D, IO-360-A1D6D, IO-360-A3B6D, IO-360-A3D6D, IO-360-C1E6D, IO-360-J1A6D, IO-360-J1AD, IO-540-C4D5D, IO-540-K1A5D, IO-540-K1B5D, IO-540-K1E5D, IO-540-K1F5D

Certain Teledyne Continental Motors engines have experienced crankshaft failures due to defects in the propeller mounting flange. Owners must remove a core sample from the propeller mounting flange and send it to TCM for evaluation.

Engine models named IO-360, O-470

Propeller mounting bolts may lose torque due to operating conditions and environmental factors, risking propeller separation. The AD requires installing improved mounting bolts, torquing them to a higher value, flying the airplane once, and retorquing as needed.

Engine models named O-360 series, O-470 series, O-540 series

Teledyne Continental Motors crankshafts are susceptible to cheek cracks that can cause engine failure and forced landing. Operators must inspect crankshaft cheeks for cracks per TCM service bulletins and replace any cracked crankshafts before further flight.

Engine models named O-470

Slick Aircraft Products magnetos on certain Textron Lycoming O-540 and IO-540 engines can experience severely worn and failed impulse couplings, which may seize the engine. Operators must remove the affected magneto and inspect the impulse coupling pawl for wear.

Engine models named IO-540-K1A5, IO-540-K1B5, IO-540-K1G5, O-540-B2B5, O-540-B2C5, O-540-E4B5, O-540-E4C5, O-540-G1A5, O-540-G2A5

Crankshaft gear retaining bolts on certain O-540-F1B5 engines have failed, risking engine failure and forced landing. Remove and replace the crankshaft gear retaining bolts on affected engines.

Engine models named O-540-F1B5

Precision Airmotive carburetors with two-piece venturis may have loose or missing primary venturis, or fuel flow disruption when a one-piece venturi is installed, causing loss of power or forced landings. Owners must either perform repetitive inspections of two-piece venturis annually, or optionally install a one-piece venturi with a new fuel nozzle as a terminating action.

Engine models named O-235, O-300 series, O-320 series

Certain cylinders in Teledyne Continental Motors E-165, E-185, E-225, O-470 and IO-470 series engines can cause extreme side loading of the piston, leading to piston and engine failure. This AD requires removal of affected cylinders and reassembly with serviceable parts per the latest revision of TCM Critical Service Bulletin CSB97-10A.

Engine models named O-470 series

Certain Lycoming reciprocal engines may have defective piston pins that could fail and cause engine failure. Affected engines must be removed from service and replaced with serviceable parts according to the referenced service bulletin.

Engine models named IO-360, IO-540, O-320, O-360, O-540

Affected cylinder assemblies can develop cracks that lead to cylinder head separation and engine failure. This AD requires removal of higher-time cylinder assemblies and replacement with serviceable parts, or dye penetrant inspections of mid-time assemblies initially and repetitively.

Engine models named IO-540-M1B5D

Certain Superior Air Parts pistons installed on O-470 series engines have failed, risking engine power loss and aircraft loss. This AD requires removal of affected pistons from service.

Engine models named O-470-K, O-470-L, O-470-R

Loose or separated engine oil filter adapters can cause loss of engine oil and engine stoppage in flight. This AD requires inspecting the oil filter adapter for security and oil leakage, applying torque putty to seal the assembly, and performing repetitive inspections of the torque putty and adapter threads.

Engine models named O-470