An airworthiness directive (AD) published September 21 finalized revisions to prior directives issued in recent years, adjusting the scope and instructions for replacement of oil filter gaskets on a range of Continental Aerospace Technologies Inc. engines, and now affecting an estimated 6,300 aircraft registered in the United States.
The new AD is the latest iteration in a series issued since an NTSB investigation prompted that agency to recommend an FAA directive requiring inspections of aftermarket oil filter installations on various Continental engines. The NTSB issued a 2020 press release calling for an AD on the adapter manufactured by F&M Enterprises, and later by Stratus Tool Technologies, an affiliate of Tempest Aero Group. Oil leaks traced to faulty adapter installations, or gasket failures, were connected to at least 11 accidents involving three fatalities at the time.
The resulting AD, effective October 26, applies to Continental engine models C–125, C145, IO–360, IO–470, IO–550, O–300, O–470, TSIO–360, and TSIO–520 series engines, as well as certain IO–520 engines with a certain oil filter adapter installed. A preceding AD required replacing a fiber oil filter gasket with a copper gasket. The new AD requires replacing the fiber gasket with a copper gasket or a stainless-steel gasket embedded with polytetrafluorethylene (PTFE).
The FAA estimates the cost of compliance, including 2.5 work hours and a $34 part, will amount to $246.50 for each aircraft, or $1.5 million to cover the estimated 6,300 engines installed with the applicable oil filter adapter assembly.