FIELD: aeronautical engineering. SUBSTANCE: flexible blade is secured on shaft 1 of main rotor so that chord of its profile is parallel to axis of rotation of main rotor shaft 1. Blade 3 is twisted relative to longitudinal elastic axis in section between shaft 1 and control carriage 2. Blade 3 takes position of setting angle of attack in control carriage 2. Blades 3 unwind during rotation of shaft 1 of main rotor under action of centrifugal force acting on weight 4. To stow away blades 3, shaft 1 of main rotor is braked. Inertial force arising at this acts on weight tangentially to trajectory of its rotation making blades wind on shaft 1. EFFECT: reduction of overall dimensions and mass of main rotor. 7 dwg
