Airworthiness Directives; Burkhart Grob Luft-und Raumfahrt GmbH & CO KG Models G103 Twin Astir, G103 Twin II, G103A Twin II Acro, and G103C Twin III Acro Sailplanes

The FAA is adopting a new airworthiness directive (AD) for all BURKHART GROB LUFT--UND RAUMFAHRT GmbH & CO KG (GROB) Models G103 TWIN ASTIR, G103 TWIN II, G103A TWIN II ACRO, and G103C TWIN III ACRO sailplanes. This AD requires you to modify the airspeed indicators and install a flight speed reduction placard and an aerobatic maneuver restriction placard (as applicable). This AD also requires you to revise the flight and maintenance manual. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. We are issuing this AD to prevent the possibility of damage to the fuselage during limit load flight due to inadequate safety margins designed into the fuselage. Such a condition could result in reduced structural integrity of the fuselage and lead to loss of control of the sailplane.