Air transport had to undergo many changes before it gained a modern look. Each type of aircraft is surprising. But especially - their ability to fly upside down and perform various maneuvers.
Flight principle
To successfully take off, the aircraft must gain sufficient speed. For example, large passenger “Boeing” accelerates to 270 km / h before takeoff. The secret of flight is concentrated in the wing structure. You can see the shape if you conditionally saw off the wing. The feature of its profile provides aircraft lift. Aviation terminology does not include the use of the term “wings”. In the narrow literature, the term wing, which consists of the left and right console, is used.
The profile has an asymmetric appearance, since its upper part has a larger area. Also, the lower and upper surfaces have different shapes. When the plane is in flight, the air moves towards him. Thus, it runs along the upper part of the wing faster than the lower surface. Here we apply the Bernoulli law: the higher the velocity of the liquid or gas, the lower the pressure indicator. It turns out that a lower pressure is formed at the top of the wing than at the bottom, respectively, it tends to rise up. So air transport overcomes the force of gravity and rises into the air, despite the considerable weight.
However, Bernoulli's law is not the only factor on which the lifting force depends. For example, airplanes that perform aerobatics or maneuvers to attack the enemy when it comes to military aircraft. They have a completely different, symmetrical wing design. However, this does not interfere with take-off, due to the presence of a positive angle.
Takeoff principle
What it is? It is easier to understand the principle of take-off with a simple example. If a person sitting inside a car moving at a sufficiently high speed puts his hand out the window with a slight tilt of his palm, then he can feel this effect on himself. The fact is that the hand will begin to rise noticeably. The same thing happens during the flight: if the pilot directs the plane up, the air pressure will increase. Due to this, the transport will begin to gain height, regardless of its weight.
At the same time, for a successful flight, one condition must be observed - air flows must evenly surround the wing of the aircraft. This phenomenon has its own term - laminar flow. If a violation of the elevation angle occurs, the correct air flows disappear, more precisely, they become vortices. In such conditions, the aircraft instantly loses its lift, and this phenomenon is considered to be a common cause of air crashes.
Interesting fact: Each aircraft model has its own lift index. It depends on the area of the wing on which the lifting force is formed. The larger the area, the higher this indicator. For example, the wing span of a Boeing is 68.5 m.The aircraft can take off with a weight of 442 tons (given its own weight and baggage, fuel, other components). The wing of the Eurostar SL aircraft has a span of 8.15 m. At the same time, its take-off weight is 470 kg.
The secret of flying upside down
It would seem, according to the theory of the formation of lifting force, an aircraft cannot fly upside down. Theoretically deployed wings will give negative lift and accelerate the fall of the aircraft. But it turns out that there is a traction vector that can be controlled. Also in the design flaps, ailerons are provided. Thus, the wing is only an auxiliary factor in flight.
The main thing is to create the right angle between the plane of the wing, as well as the direction of flight of the vehicle. When the aircraft picks up speed, the air flow under the wings becomes denser, and pressure rises in it. At the same time, over the plane of the wings, the pressure level drops - traction is formed. The correct angle is also called the angle of attack.
Both wings are specially positioned in the aircraft structure so that they are slightly turned forward. If you try to rotate such an aircraft during a flight upside down, it will begin to quickly fall down. However, the correct (positive) angle of attack will keep it at the same height. For this, the pilot needs to point the nose of the structure up so that it "looks" into the sky.
Large passenger liners will not cope with this task because of their gravity, as well as insufficient strength.Sports planes can easily move in their normal and inverted positions. Just for such maneuvers, they are equipped with symmetrical wings. Moreover, their location is important - in parallel with respect to the axis of the housing. When the plane takes off, its front end always lifts higher towards the sky than passenger liners.
In the normal position, the aircraft gains altitude because low air pressure forms above the wing, and high air pressure below it. This is due to the asymmetric shape of the wing and the features of its location. It is also necessary to observe a positive angle of attack. This is the angle that is formed between the direction of movement of the aircraft and the surface of the wing. Airplanes can fly upside down, which, thanks to their design, are able to change this angle.
