AD Likely Coming For Lycoming Rod Bushing Issue

As you've likely heard, Lycoming released a Service Bulletin (SB632) recently calling for the inspection of late model engines or those engines overhauled within the past couple of years that might have connecting rod bushings (made from November of 2015 to November of 2016) that don't fit properly and are therefore subject to damage, potentially leading to a catastrophic engine failure.

Lycoming wants the affected engines---the list of affected models is long but no word on how many engines are affected, likely thousands---to be inspected to ensure the bushings installed are conforming, but that process is involved, complicated to perform and expensive. Lycoming has reportedly said that it would pay for the service on the engines with under-warranty factory new engines and factory overhauled engines that are addressed by the service bulletin. The company has even created a tool for the purpose of the testing.

A Lycoming employee demonstrating the inspection process as outlined in SB 632.

Already, consumer and industry groups have suggested alternate means of compliance with the service bulletin, including examining the engine oil for bushing material that might indicate the deterioration of one of the non-conforming parts. Savvy Aviation, a company focusing on engine management and maintenance said on its website that the less invasive inspection process would be far less costly and lessen the possibility of faulty repairs with creating power loss problems in previously healthy engines.

The FAA was widely expected to issue an airworthiness directive in response to the Lycoming service bulletin. We'll keep you updated on the story as we learn more.

Here are the specifics of the mechanical issue with the affected Lycoming engines.