Plane goes up in the airs !
The Second world war s’ is played as of the middle of the Thirties. Indeed, l’ Germany rearms and undertakes its annexations, Japan invades China. Thus take off Messerschmitt 109 (called “L’ untiring eagle”) and its opponents Spitfire, B-17, or even the DC-3. The engines are from now on range of the 1000 horses, actuating propellers at constant speed thus allowing profits spectacular speed. The planes offer a greater aerodynamic purity . The war d’ Spain, of 1936 to 1939, shows which d’ degree extremely well; effectiveness can reach l’ arms air. C’ is very late that the European countries become aware of l’ importance of the air power. In 1939, l’ Germany believes itself ready to make the war…
Great Britain s’ is rearmed and s’ is equipped with stations of detection radar. Royal Air Force is made up d’ modern planes; while France, it, n’ is not prepared. D’ elsewhere the Vuillemin general, chief of l’ Army of l’ Air, said, at the time d’ one of its visits in Germany in 1938: “Alas! S’ there was the war…”. More the military great power of 1916 saw its aviation nationalized in 1936 by the government of the Popular front. The industrial production however increases and France has good planes: but the command is late d’ a war… Even the United States, neutrals at this time, s’ worry about the European situation and launch modernization programs. In 1945, the world changed face.
A bomber pressurized four-engined plane launched twice an atomic bomb. The waves of English and American heavy bombers crushed l’ Germany, without destroying its potential completely. The latter was the first to bring into service jet fighters, rockets, missiles of all types. But the war was gained by the number on ground, sea and in the airs… O O O TECHNIQUE: How does a plane fly? To include/understand the way in which a plane succeeds in flying it is necessary to explain the main forces to which it is subjected. The weight. This force due to the universal gravitation is directly proportional to the mass of the bodies. Directed to the bottom it n’ involves; import which object towards the ground. The bearing pressure is the force resulting from the deviation of flow d’ air around l’ wing d’ a plane. Profile of l’ wing slightly curved according to very precise dynamic properties allows d’ to obtain an effect of bearing pressure. The pressure which s’ exert on lower surfaces (under-surface) is more important, involving an upswing, and less important on the upper parts (suction face) of l’ wing causing a strong aspiration upwards. This is due to the special profile of l’ wing, conceived to cause an acceleration of l’ air on its surface by thus decreasing the pressure. C’ is what l’ one calls the Venturi phenomenon. The trail d’ a body in l’ air is a force which s’ oppose to its displacement.
It depends on the form, of l’ state of surfaces, the speed of l’ object and of the characteristics of l’ air. The propulsion is the force which will make it possible to overcome the trail. Exerted by the system of propulsion of l’ apparatus it s’ obtains by moving l’ air towards l’ back with l’ helps of l’ propeller, which advances l’ plane. In level flight (altitude and speed constants), these four forces s’ two to two balance, the propulsion compensating for the trail and the bearing pressure neutralizing the weight.
For qu’ a plane goes up in the airs it is necessary that the force of bearing pressure is higher than its weight. The pilot inclines the nose of l’ gradually; plane to the top, but attention, if this operation is exaggerated it can have unhooking there. Beyond d’ a certain angle d’ attacks compared to flow d’ air, l’ plane will take down because the bearing pressure decreasing brutally it starts to fall. The situation of unhooking involves an important rate of fall but l’ apparatus can remain well flat and completely controllable (one calls this type of unhooking ” statique” with null slope) one can also make the same thing in turn and there the rate of fall becomes more important. That can go jusqu’ with l’ car rotation called also ” vrille”. The stalling speed can vary according to the configuration of l’ apparatus (plane in turn, train d’ left landing, position of the shutters and weight).