1 November 2024
A huge number of Lycoming engines will have to comply with a new Airworthiness Directive that comes into force on 5 December 2024.
The Airworthiness Directive (AD) applies to engines that had certain connecting rod assemblies installed between the years 2009 and 2017. It follows reports of connecting rod failures, which resulted in uncontained engine failure and in-flight shutdowns.
The AD requires repetitive oil inspections for bronze metal particulates and, if found, additional inspections of the connecting rod bushings for damage, proper fit, movement, and wear, and replacement if necessary.
According to the US regulator, the FAA, Lycoming has determined that degradation of the connecting rod small end bushings is detectable during oil change inspections.
The AD describes the required actions as:
At the next oil change or within 4 months after the effective date of this AD, whichever occurs first, and thereafter at every oil change until the bushing replacement required by either paragraph (g)(3) or (4) of this AD is done, perform a visual inspection of the engine oil filter, oil pressure screen, and oil suction screen (depending on the engine configuration) for bronze metal particulates.
The actions required by this paragraph may be performed by the owner/operator (pilot) holding at least a private pilot certificate and must be entered into the aircraft records showing compliance with this AD.
The affected parts are known to be installed on these Lycoming engines:
The FAA estimates that this AD affects 16,000 engines in the US alone. There’s no estimate of how many outside the US are affected.
See the FAA Airworthiness Directive in full here
