In an action meant to address an “unsafe condition” on Diamond twins using these engines, the FAA published an airworthiness directive on July 27, that applies to certain Austro Engine GmbH model E4s and all E4P engines. The directive follows up on reports of “considerable wear of the timing chain on the affected engines,” according to the publication in the Federal Register. The AD supercedes a Notice of Proposed Rulemaking published on October 25, 2018, calling for periodic inspections of the timing chain and updates to the aircraft flight manuals (AFMs) in question to limit the use of windmill restarts during emergency procedures. The engines can be found in the DA42 NG and the DA62.
“The European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA AD 2017-0103R1, dated February 25, 2019 (referred to after this as “the MCAI”), to address the unsafe condition on these products. The MCAI states: ‘Considerable wear of the timing chain has been detected on some engines. This may have been caused by windmilling restarts, which are known to cause high stress to the timing chain. This condition, if not detected and corrected, could lead to failure of the timing chain and consequent engine power loss, possibly resulting in reduced control of the aeroplane.’”
