The invention provdies a thrust reverser system (40) which is used for reducing aerodynamic disturbance in a secondary channel of a two-flow turbine engine in an air vehicle. The thrust reverser system with a thrust reverser cascade (46) and a reverser door with door segments (50a, 50b) laid out in a folded condition relatively to each other in an inactive configuration of the reverser system, andaccommodated in an accommodation space (60) located outside the secondary channel (24). Upon passing from the inactive configuration to the active configuration a rearward displacement of the cascadetowards a nacelle aperture, released by an external movable nacelle cowl (28) driven rearwards by the cascade, and a deployment of segments until they attain a deployed closing position within the secondary channel occurs simultaneously.