Airworthiness Directives; Stemme AG (Type Certificate Previously Held by Stemme GmbH & Co. KG) Gliders

The FAA is adopting a new airworthiness directive (AD) for certain Stemme AG (type certificate previously held by Stemme GmbH & Co. KG) 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 identifies the unsafe condition as a deviation in the construction of the connection of the inner wing to the outer wing, resulting in a wrong positioning of the glass-fiber reinforced plastic (GFRP) blocks. This AD requires inspecting the left-hand (LH) and right-hand (RH) outer wing spars for correct positioning of the GFRP blocks and, if incorrect positioning is found, repairing of the reinforcement blocks. The FAA is issuing this AD to address the unsafe condition on these products.