Jumping from heaven
Trite, but the parachute was also invented by Leonardo da Vinci. In addition to the helicopter and the flying saucer, which he himself could not translate into materials contemporary to him, in his diaries he described a certain “tent” from which one can safely jump from any height.
Actually, the parachute dome was built several centuries later. For some time with a parachute it was possible to jump only from an aerostat, to the bottom of which the dome was fastened in an unfolded form. At the beginning of the 20th century, Gleb Kotelnikov, shocked by the death of a famous aeronaut, invented a parachute that fits into a metal satchel. This made it possible to jump from an airplane. That is, to obtain successively the separation of a person from an aircraft and the voluntary opening of a parachute.
At the beginning of World War I, Kotelnikov’s invention was not at first approved. The Grand Duke Alexander Mikhailovich, the chief of military aviation, said that the pilots would use the parachute unreasonably and stop taking care of expensive aviation equipment. Intervened statistics. She stubbornly showed that the pilots were massively killed along with the machines. Russia began to buy parachutes in France, where Kotelnikov’s knapsacks had already been set up – though not in the best modification. Only the young Soviet state allowed the inventor to see the fruits of his labors in serial production at home.
How it works
Since then, the principle of operation of the parachute remains the same, only details are being improved. The parachutist girds himself with a suspension (circular belt system) and adjusts it to his height-size with the help of locking buckles. The suspension straps attached to the suspension in two places are connected by a high-strength synthetic silk dome to the slings. The dome itself fits into a canvas satchel so that it is easy and quick to turn around in the air stream. The satchel is equipped with four flaps that open like an envelope. The valves are fixed with locking pins connected to the tension bands. Separated from the aircraft, the paratrooper pulls the ring (or – in modern parachutes – a small pear), connected by a rope with a stud. Studs are removed from the cones, freeing the stretched elastic bands that quickly open the valves, and the dome, falling directly into the upward air flow, opens over the parachutist.
The force of air resistance acts on the dome, which is equal to the force of gravity acting on the skydiver. Due to this, the parachute and parachutist system decreases at a constant speed. The rate of decline of modern domed parachutes is 5.5 m / s.
Parachute deployment is mostly forced and manual. Another is the disclosure of a stabilizing dome and insuring device. Forced disclosure takes place with an exhaust file attached at one end to a cable taut in the plane and at the other end to the details of the parachute system. After the disclosure of the exhaust halyard remains in the plane, and the parachutist flies about his business, that is, down.
Manual deployment is initiated by the parachutist himself. Until recently, a ring or a link was provided on parachute systems, when it was pulled out, a backpack was opened, from which a parachute was ejected by a spring, and he, in turn, pulled the main parachute from the backpack. This system is bulky, heavy, it has a lot of extra details. In addition, the problem is where to put the ring after disclosure. Therefore, fifteen years ago, another system became widespread: the exhaust parachute was made in a form convenient for folding into an outer pocket on a satchel. For disclosure, the parachutist simply takes it out of his pocket and throws it into the stream. Such an exhaust parachute was called “jellyfish”. He really looks a bit like this animal – round and shapeless.
But if two different devices do the same thing, then among them there is not one better – the “jellyfish” also has drawbacks. The biggest one – it may not work if the parachuter’s body is not optimally positioned when deployed. Therefore, on the training and spare parachutes used the old scheme – exhaust parachute with a spring.
How to fall
The optimal position of the parachutist’s body during deployment is lying face-up on the upstream. With some experience, it is not difficult to go into such a position from any random fall: you just need to give your body the correct aerodynamic shape, and the air flow will turn it as it should.
This form can be rehearsed before the flight. You need to lie on the ground face down, arms and legs spread to the sides, lift them higher and bend your back. So it is convenient to fly, and the parachute opens correctly.
The dome is controlled by two control lines, which the parachutist directs the parachute to the right or to the left. Pulling two lines at the same time, he reduces the horizontal speed. You can pull other lines, with a slightly increased vertical speed, but in practice, no one uses it.