The adapters, which enable the use of spin-on oil filters on the engines instead of the original brass oil screens, have been associated with power-loss accidents caused by oil starvation, including a fatal accident involving a Cessna 182P airplane on May 1, 2019.
The FAA acted to raise awareness of the problem by issuing a Safety Alert For Operators (SAFO) on January 6. The SAFO applies to airplanes equipped with Continental Motors Inc. O-470, IO-470, IO-520, IO-550, TSIO-520, GO-300, IO-360, TSIO-360, C-125, C-145, and O-300 model engines that have had the adapters listed in the SAFO installed under supplemental type certificates.
The SAFO notes that “the parts may be stamped with either F&M Enterprises, Inc. or Stratus Tool Technologies, LLC as the manufacturer.”
Concerns about the oil filter adapters have also been raised by the NTSB. In December, AOPA reported that the NTSB had issued a safety recommendation urging the FAA to issue an airworthiness directive that would require operators to inspect adapters as directed in a manufacturer’s service bulletin—a level of compliance, the safety agency noted, that would not otherwise be mandatory for Part 91 operators.
AOPA encouraged aircraft operators to comply with the manufacturer’s procedures, and on December 8, the AOPA Air Safety Institute published a Safety Notice to help inform aircraft operators about the NTSB’s recommendation.
To help owners determine whether their aircraft are affected, the SAFO notes that the holder of STC SE09356SC was F&M Enterprises “from the original issuance date of October 14, 1997. On July 13, 2015, the STC was re-issued to Stratus Tool Technologies, LLC, which remains the current holder. There are both F&M- and Stratus-manufactured oil filter adapters with part numbers (P/N) C6LC-S and C6LC-L currently installed in various Continental Motors engines in service.”