Investigation into Uncommanded Engine Shutdowns in Widely Used Training Aircraft
The Federal Aviation Administration (FAA) issued an Airworthiness Concern Sheet on December 16, 2025. This marked the beginning of an investigation into reports of uncommanded engine shutdowns in aircraft equipped with Lycoming IO-360 engines when throttled to idle.
Multiple reports of unexpected engine rollbacks on aircraft using AVStar-manufactured vertical and horizontal mounted fuel servos prompted the investigation. These incidents have been reported across a range of popular training aircraft, including:
- Cessna 172S
- Cessna 172R
- Piper Archer III
- Piper Pilot 100i
- Piper Seminole models equipped with IO-360 engines
The FAA is urging operators, maintainers, and owners of aircraft with IO-360 engines to provide detailed information about any observed rollback events. This request applies regardless of fuel servo manufacturer or installation orientation. The agency is seeking data on both ground and flight operations, including actions performed and outcomes.
The fuel-injected four-cylinder IO-360 is a common feature on recent training aircraft models used by flight schools across the country. The Airworthiness Concern Sheet is a tool the FAA uses to gather information about potential safety issues under investigation. This can lead to various resolutions, including possible airworthiness directives.
Source: General Aviation News