Prompted by reports of engine exhaust leaks from Lycoming TIO-540-AJ1A engines, found most commonly on the Cessna T206 Turbo Stationair, a new urgent Airworthiness Directive requires inspection of the exhaust system within in the next 10 hours time-in-service (TIS) "to prevent engine exhaust leaks, which could lead to uncontrolled engine fire, harmful exhaust gases entering the cabin resulting in crew incapacitation, and damage to the airplane," says the FAA. Because of the FAA's determination that the exhaust leaks pose an immediate risk to flight safety, the AD was not subject to the customary notice and comment period, but Lycoming is working to determine the root cause of the leaks, and the FAA says it will consider revising when it has Lycoming's conclusions in hand.
This is a companion discussion topic for the original entry at https://www.avweb.com/news/updated-urgent-ad-for-lycoming-tio-540