A helmet-mounted display system comprising a helmet shell and a mechanical arch mounted on the front part of said shell, the mechanical arch comprising: a fixed position detection device; a display device; a means for holding and adjusting the display device in the vertical plane, said holding and adjustment means consisting: of a first vertical support surface disposed in the front part of the arch and at right angles to the sagittal plane of the shell, said flat support comprising an oblong port; of a screw - spring assembly which ensures the fixing and the adjustment of the display device on the flat support, the screw passing through the oblong port and being fixed in a mechanical structure of the display device, the display device being able to rotate with friction about the axis of the screw so as to make it retractable; characterised in that the display system comprises a means for roll adjustment and repositioning of the display device, said adjustment and repositioning means consisting: of a second vertical support surface, normal to the first support surface; of a knurled screw with spherical end attached to the mechanical structure of the display device, the axis of the knurled screw being at right angles to the screw-spring axis and in a horizontal plane, the end of the screw resting on the second support surface when the display device is in its position of use. a fixed position detection device; a display device; a means for holding and adjusting the display device in the vertical plane, said holding and adjustment means consisting: of a first vertical support surface disposed in the front part of the arch and at right angles to the sagittal plane of the shell, said flat support comprising an oblong port; of a screw - spring assembly which ensures the fixing and the adjustment of the display device on the flat support, the screw passing through the oblong port and being fixed in a mechanical structure of the display device, the display device being able to rotate with friction about the axis of the screw so as to make it retractable; characterised in that the display system comprises a means for roll adjustment and repositioning of the display device, said adjustment and repositioning means consisting: of a second vertical support surface, normal to the first support surface; of a knurled screw with spherical end attached to the mechanical structure of the display device, the axis of the knurled screw being at right angles to the screw-spring axis and in a horizontal plane, the end of the screw resting on the second support surface when the display device is in its position of use. of a first vertical support surface disposed in the front part of the arch and at right angles to the sagittal plane of the shell, said flat support comprising an oblong port; of a screw - spring assembly which ensures the fixing and the adjustment of the display device on the flat support, the screw passing through the oblong port and being fixed in a mechanical structure of the display device, the display device being able to rotate with friction about the axis of the screw so as to make it retractable; characterised in that the display system comprises a means for roll adjustment and repositioning of the display device, said adjustment and repositioning means consisting: of a second vertical support surface, normal to the first support surface; of a knurled screw with spherical end attached to the mechanical structure of the display device, the axis of the knurled screw being at right angles to the screw-spring axis and in a horizontal plane, the end of the screw resting on the second support surface when the display device is in its position of use. of a second vertical support surface, normal to the first support surface; of a knurled screw with spherical end attached to the mechanical structure of the display device, the axis of the knurled screw being at right angles to the screw-spring axis and in a horizontal plane, the end of the screw resting on the second support surface when the display device is in its position of use.