EASA AD US-2023-17-04: Engine - Oil Filter Adapter Gasket - Replacement

What to do

Affected operators must remove any fiber gasket from F&M or Stratus oil filter adapters and replace it with a copper gasket (P/N AN900-28 or AN900-29) or a stainless steel PTFE gasket (P/N ST07) within 50 flight hours after October 26, 2023, or at the next scheduled oil change, whichever occurs first. Installation of fiber gaskets on these adapters is prohibited after the effective date. Compliance should follow the instructions in Stratus Tool Technologies Mandatory Service Bulletin SB-001 Rev C dated June 16, 2022.

Summary

Airworthiness Directive 2023-17-04 is a final rule issued by the Federal Aviation Administration addressing certain Continental Aerospace Technologies, Inc. engines including models C-125, C-145, GO-300, IO-360, IO-470, IO-520, IO-550, O-300, O-470, TSIO-360, and TSIO-520 equipped with F&M Enterprises or Stratus Tool Technologies oil filter adapters. The directive mandates replacing the oil filter adapter fiber gasket with either a copper gasket or a stainless steel polytetrafluoroethylene gasket to prevent engine power loss caused by oil starvation. This AD applies to engines installed on U.S. registered aircraft and aims to enhance engine reliability and safety.

What changed

This AD supersedes AD 2022-04-04 and expands the applicability to include additional Continental engine models equipped with F&M or Stratus oil filter adapters. It introduces the option to replace the fiber gasket with either a copper gasket or a stainless steel PTFE gasket as an improved alternative. The directive also removes certain engine models with permold type crankcases from applicability and incorporates updated service information from Stratus Tool Technologies.

Why it matters

This directive is critical for aviation professionals because it addresses a safety issue linked to two accidents caused by engine power loss due to oil starvation. Operators and maintenance organizations must comply to prevent potential engine failure, in-flight shutdown, and loss of aircraft control. Ensuring timely gasket replacement reduces the risk of costly incidents and enhances overall flight safety.