AD FAA-2013-0145

We are adopting a new airworthiness directive (AD) for Agusta S.p.A. (Agusta) Model AB412 and AB412 EP, and Bell Helicopter Textron (Bell) Model 412, 412CF, and 412EP helicopters with certain DART Aerospace Ltd. (Dart) high gear aft crosstubes (crosstube) installed. This AD requires adding a life limit of 10,000 landings to the crosstube and removing from service any crosstubes with more than 10,000 accumulated landings. This AD is prompted by five separate reports of crosstube failures. The actions in this AD are intended to prevent failure of the crosstube and subsequent collapse of the landing gear.