Airworthiness Directives; Glaser-Dirks Flugzeugbau GmbH Model DG- 500M Gliders

This amendment adopts a new airworthiness directive (AD) that applies to all Glaser-Dirks Flugzeugbau GmbH (Glaser-Dirks) Model DG- 500M gliders. This AD requires installing a rudder gap seal and modifying the cooling liquid reservoir mount. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. The actions specified by this AD are intended to prevent rudder vibrations caused by flow separation at the rudder gap, which could result in flutter with consequent loss of rudder control.