Airworthiness Directives; Eurocopter France Helicopters

We are adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model EC 155B and EC155B1 helicopters. This AD requires repetitively inspecting the lower and upper front and rear fittings (fittings) that attach the upper fin to the fenestron for a crack and, if there is a crack, removing all four fittings from service. This AD also requires, within a specified time, removing all fittings from service, and the fittings would not be eligible to be installed on any helicopter. This AD was prompted by the loss of an upper fin in flight. The actions of this AD are intended to detect a crack in the fittings to prevent loss of the upper fin and subsequent loss of control of the helicopter.