Summary
We propose to adopt a new airworthiness directive (AD) for certain Lycoming TIO-540-AJ1A reciprocating engines. This proposed AD was prompted by several reports of cracked engine exhaust pipes. This proposed AD would require inspection of the engine exhaust pipes for cracks and replacement of the turbocharger mounting bracket. We are proposing this AD to prevent failure of the exhaust system due to cracking, which could lead to uncontrolled engine fire, harmful exhaust gases entering the cabin resulting in crew incapacitation, and damage to the airplane.