Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to the Burkhart Grob, Luft- und Raumfahrt (Grob) Model G 103 C Twin III SL sailplanes. The proposed action would require inspecting the propeller bearing and upper pulley wheel for increased play and, if increased play is found, modifying the propeller bearing and pulley wheel with a part of improved design. The proposed action is prompted by two reports of Model G 103 C Twin III SL sailplanes losing the engine propeller while in flight and one operator finding increased play in the sailplane propeller during an inspection. The actions specified by the proposed AD are intended to prevent the loss of the sailplane engine propeller and possibly causing loss of the sailplane.