Airworthiness Directives; Eurocopter Canada Ltd. Model BO 105 LS A-3 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-20-13, which was sent previously to all known U.S. owners and operators of Eurocopter Canada Ltd. Model BO 105 LS A-3 helicopters by individual letters. This AD requires, before further flight, creating a component log card or equivalent record and determining the age and number of flights on each tension-torsion (TT) strap. The AD also requires inspecting and removing, as necessary, certain unairworthy TT straps. This amendment is prompted by an accident in which a main rotor blade (blade) separated from a Eurocopter Deutschland GMBH Model MBB-BK 117 helicopter because of fatigue failure of the TT strap. The Model MBB-BK 117 and the Model BO 105 LS A-3 helicopters use the same part-numbered TT strap. The actions specified by this AD are intended to prevent failure of a TT strap, loss of a blade, and subsequent loss of control of the helicopter.