Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2018-18-02, which applies to certain Austro Engine GmbH model E4 engines and to all Austro Engine E4P engines. AD 2018-18-02 requires replacement of the timing chain and amending certain airplane flight manuals (AFMs) to limit the use of windmill restarts only as an emergency procedure. Since the FAA issued AD 2018-18-02, Austro Engine GmbH revised the applicable Airworthiness Limitation Section (ALS) including the limitation required by AD 2018-18-02 for the timing chain subjected to a windmill restart. This proposed AD would require amendment of certain existing AFMs to limit the use of windmill restarts and remove the timing chain replacement requirement that exists in AD 2018-18-02. The timing chain replacement requirement in accordance with new life limits defined in the revised ALS will be proposed in a new and separate AD. The FAA is proposing this AD to address the unsafe condition on these products.