Get the latest news on coronavirus impacts on general aviation, including what AOPA is doing to protect GA, event cancellations, advice for pilots to protect themselves, and more. Read More
Already a member? Please login below for an enhanced experience. Not a member? Join today

ASI SAFETY NOTICE: 2020-2Safety Notice Stratus STC Oil Filter Adapter Assembly Linked to Loss of Engine Power

Safety Notice Striped Banner Bar

The Issue:

A National Transportation Safety Board (NTSB) investigation of airplane accidents experiencing loss of engine power on certain Continental engine models attributed the power loss to a Stratus Tool Technologies oil filter adapter assembly—including maintenance of the oil filter adapter assembly—installed under a supplemental type certificate (STC). In each of these accidents, oil leaked from the assembly, resulting in oil starvation to the engine and a subsequent total loss of engine power.

On October 25, 2019—in response to the NTSB findings and other reports of oil leaks—Stratus issued mandatory service bulletin (SB-001) to the owners of affected aircraft.

What You Should Know

To prevent further accidents due to loss of engine power in the affected airplanes, the AOPA Air Safety Institute urges pilots and owners to comply with SB-001 before their next flight. The bulletin provides mechanics and owners instructions on inspecting, then retorqueing or reinstalling its oil filter adapters to prevent possible oil loss and a subsequent engine failure resulting from misaligned gaskets, rotated housing, or improper torque. The work to comply is not intrusive, nor is it expensive, and it saves lives.

What You Should Do

Read and share the Stratus mandatory service bulletin SB-001 with your mechanic, and comply with the bulletin’s steps before your next flight.

Your mechanic will inspect the adapter for leaks, gasket damage or protrusion, and movement of the assembly; reinstall the oil filter adapter, if necessary; tighten the cylinder torque to 65 lbf-ft; and install safety wire.

You should inspect the oil adapter before your next flight, every time the oil is changed, each 100-hour or annual inspection, and whenever the adapter is removed and installed.

Mechanics and owners should make sure to include a detailed logbook entry referencing Service Bulletin Number SB-001 dated 12/19/19 (or later revisions) to show compliance with the bulletin.


To increase safety awareness and help reduce accidents, the AOPA Air Safety Institute periodically issues Safety Notices to remind pilots of significant safety topics.