Rotorcraft with at least one main rotor and at least one counter-torque rotor

摘要

The invention is related to a rotorcraft 1 with at least one main rotor 1a and at least one counter-torque rotor 11a, comprising: at least one duct-type portion 10 provided with a shroud 3 that defines at least one transverse duct 6, said at least one counter-torque rotor 11a comprising a plurality of counter-torque rotor blades 13 and being rotatably arranged within said at least one transverse duct 6, and said shroud 3 being equipped in the region of said at least one transverse duct 6 at least partly with a liner arrangement 3a, said liner arrangement 3a being at least adapted for tonal and broadband sound absorption.