Summary
We propose to adopt a new airworthiness directive (AD) for the Aeronautical Accessories Inc. (AAI) High Landing Gear Aft Crosstube Assembly (aft crosstube) installed on certain Bell Helicopter Textron, Inc. (Bell) and Agusta S.p.A. (Agusta) model helicopters as an approved Bell part installed during production or based on a Supplemental Type Certificate (STC). This proposed AD is prompted by three reports of failed crosstubes because of cracks. The proposed actions are intended to prevent failure of a crosstube, collapse of the landing gear, and subsequent loss of control of the helicopter.