Abstract: A two dimensional supersonic air intake is provided for the combustion air f an aircraft engine comprising on one side a front flap (3) forming a visor and on the other side a fairing (4). The front flap (3) is movable about a pivoting axis (5) situated opposite the fairing (4). The front flap (3) is fast with a mobile fairing nose (6) situated in front of fairing (4) and moving in front of the latter when the front flap (3) moves in the direction which increases the air intake section.

Abstract: The optical sighting device makes it possible to increase the quality of ical transmission by preventing turbulences from forming in the field of vision at high speed, by means of an airstream-deflecting device which is mounted in the turbulence formation zone and which has a profile in the form of a stem-post to dispel the air-streams laterally. In the case of transparent plane wall via which vision takes place in this zone, the deflecting device can consist of an attached plates which is connected to or located in the vicinity of the wall.

Abstract: A propeller nozzle, particularly for a missile, comprises a revolution pipe having a forward convergent portion, a minimum section, and a rearward divergent portion with a large outlet throat section. The invention is designed to minimize lateral forces in the nozzle due to a separation of gaseous fluid exhausting from the propeller, during the start of the propeller pressure increase. For this purpose, the pipe comprises means disposed in the vicinity of a section internal to the divergent portion and substantially downstream from the minimum section for making a gaseous fluid separation stable, symmetrical and coaxial to the nozzle. These means can include a groove and/or a projection, preferably destroyable through mechanical erosion and/or melting under the effects of the gaseous fluid.