Aviation gas turbine thrust reversing device

The gas turbine thrust reverser has a cowl (28) whose rear portion (30) is more displaced in the axial direction of an engine. An annular free space arises in a front portion (29) of the cowl. The turning elements and blockage elements are coupled to rear portion of the cowl. A drive element is arranged between the front portion and the rear portion to cause axial displacement of the rear portion. A drive element is formed in two stages for partial and full axial displacements of rear portion of cowl.