Airworthiness Directives; Stemme GmbH Gliders

Official abstract: The FAA is adopting a new airworthiness directive (AD) for all Stemme GmbH (Stemme) Model Stemme S 12 gliders. This AD was prompted by reports of fuel leaking around certain copper sealing rings within the fuel system. This AD requires repetitive visual checks of the fuel system for fuel leakage, and replacement of the affected copper sealing ring. This AD also prohibits the installation of affected parts. The FAA is issuing this AD to address the unsafe condition on these products.