S12 FAA AD ASI Replacement

Docket No. FAA-2021-0716; Project Identifier 2019-CE-023-AD; Amendment
39-21799; AD 2021-23-01

The FAA is adopting a new airworthiness directive (AD) for all Stemme AG Model Stemme S 12 gliders. This AD was prompted by mandatory continuing airworthiness information (MCAI) issued by the aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as an airspeed indicator (ASI) with speed markings inconsistent with the approved and published values. This AD requires inspecting the ASI markings and, depending on findings, either replacing the ASI or amending the existing aircraft flight manual (AFM) until the ASI is replaced. The FAA is issuing this AD to address the unsafe condition on these products.