Airworthiness Directives; Glaser-Dirks Flugzeugbau GmbH Model DG- 400 Gliders

This amendment adopts a new airworthiness directive (AD) that applies to all Glaser-Dirks Flugzeugbau GmbH (Glaser-Dirks) Model DG- 400 gliders. This AD requires replacing the propeller shaft, the bearings, and the front drive belt retaining rings with ones of improved design. 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 failure of the propeller shaft caused by an ineffective design, which could result in loss of glider propulsion during critical phases of flight.