Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-06-15 which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (BHTC) Model 407 helicopters by individual letters. This AD requires installing a tail rotor pitch-limiting left-pedal stop, installing an airspeed limitation placard, marking a never-exceed velocity (Vne) placard on all airspeed indicators, and revising the Limitations section of the Rotorcraft Flight Manual (RFM). This amendment is prompted by three accidents involving inflight tail rotor blade strikes against the tailboom. The actions specified by this AD are intended to prevent the tail rotor blades from striking the tailboom, which could result in separation of the aft section of the tailboom with the tail rotor gearbox and vertical fin, and subsequent loss of control of the helicopter.