FAA concerned about exhaust leaks on a Lycoming engine

The airworthiness concern sheet is the first ever issued by the FAA’s Engine and Propeller Directorate. It follows a service bulletin issued Aug. 31 by the engine manufacturer, citing field reports of exhaust leaks resulting from cracked welds and exhaust studs pulling from a cylinder on some engines, said David Oord, AOPA senior director of regulations.

Mandatory Service Bulletin 627A, issued by Lycoming Aug. 31, requires inspection of the exhaust system within 10 hours from the date of its issuance and then every 25 flight hours for engines with less than 1,000 hours, or every 50 flight hours for engines with more than 1,000 hours.

An airworthiness concern sheet gives the FAA a means to communicate airworthiness concerns to aircraft owners and operators pending possible further action.

“At this time, the FAA has not made a determination on what type of corrective action, if any, should be taken. The resolution of the airworthiness concern sheet could involve an airworthiness directive action, a special airworthiness information bulletin, or the FAA could determine that no action is needed at this time,” Oord said. The decision could depend on evaluating information received as a result of the airworthiness concern sheet being issued.

The Engine and Propeller Directorate’s issuance of an airworthiness concern sheet in this case was a response to discussions on how to best address safety concerns between industry participants and the FAA at last year’s AOPA/FAA GA Engine Summit, Oord said.

“One of the key issues discussed was how to involve the industry sooner in the risk-analysis process that could eventually lead to an AD,” he said. “It is important for the industry to engage with the FAA early in this process to fully understand the airworthiness concern, its magnitude, and severity, to produce the most effective safety risk management.”

Members who have experienced cracked exhaust pipes on Lycoming TIO-540-AJ1A engines (which are used, for example, on some models of Cessna 206 airplanes) are encouraged to contact AOPA’s Pilot Information Center.

In particular, AOPA is interested in similar incidents, inspection and/or repair procedures implemented, and costs involved in the repair. Other comments are also welcome, including any mitigation or alternatives.