Classification of aircraft speed
The first aircraft, or rather, their predecessors – the gliders of the Wright brothers – was moving at a low speed of about 50 kilometers per hour. Gradually the designs of these aircraft were improved, and if more recently, hundreds of kilometers per hour was considered a great speed, today the aircraft can fly at speeds that surpasses the speed of sound.
Distinguish between subsonic, transonic, supersonic and hypersonic aircraft. Sound moves at different speeds depending on the density and elasticity of the medium: in the air, it amounts to little more than 1200 kilometers per hour.
The speed of the various aircraft
From passenger aircraft to distinguish between cruising and maximum speed, with both values do not exceed the speed of sound, so all models are subsonic. Cruising speed is about 60 to 80% of the maximum: so fly these machines with passengers on Board, they rarely accelerate to the maximum. Different types of passenger aircraft of different cruising speed. So, Tu-134 flying about 880 kilometers per hour, the Il-86 – 950, Boeing from 910 to 940. The maximum speed of the fastest passenger aircraft is around 1030 miles per hour: in any case, this is less than the speed of sound, but close to it.
There are projects transonic passenger aircraft: for example, this was supposed to be a Boeing Sonic Cruiser, but this project was never finished. In the United States today banned from flying with such speed, in Europe, if the unit does not produce a sonic boom. Also previously operated two passenger aircraft, flying at the speed of sound: Tu-144 (worked until 1978) and "Concord" (released from service in 2003).
Speed transvalued aircraft is the speed of sound, and supersonic is superior. These aircraft are mostly military: the fighters, scouts, interceptors, bombers. To the same velocity, accelerate spacecraft.
Hypersonic aircraft, so far, their speed exceeds the speed of sound in 8-9 times. The fastest of them – NASA X-23A, which accelerates to 11230 miles per hour. The first such machine appeared in 60-ies in the United States and has made suborbital space flight. In fact, it's space ships and their pilots can be called astronauts, if they rise above the boundaries of space, 100 kilometers.