Flight on a fighter in GTA 5 online: how to do it

There are several types of fighters introduced in the game. First type is usual military fighters that you can see on special military territory and it is rather hard to get there. Second type is introduced by special plane "Hydra". You can buy it in a special airplane shop, it is impossible to find this plane.
This unique plane has the following pros:

This transport is the most dangerous in the game
it has a function of horizontal and vertical flight
it is equipped with rockets and special guns that cause great damage
it could withstand the hit of several rockets

Usual fighter is similar to civil passenger plane in controlling, but here appears space button or button of your mouse, that is designed for shooting. Plane doesn't have any armor and explodes from one rocket.
Hydra is different from another aeroplanes because it has the function of vertical takeoff. To do this you should press "E" button and regulate the height. In this mode Hydra could also soar in the air and attack objects. It is hard to manage this plane, but if you will learn to do it, you may become one of the strongest players in the GTA online.