What is an aileron? This is an aerodynamic control (roll rudders), which is equipped with conventional aircraft and created according to the "duck" scheme. Ailerons are located on the trailing edge of the wing consoles. They are designed to control the angle of inclination of the "iron birds": at the moment of application, the roll rudders deviate in opposite directions, differentially. In order for the aircraft to tilt to the right, the left aileron is directed down, and the right aileron is directed up, and vice versa.
What is the principle of operation of the roll rudders? The lift force is reduced in that part of the wing, which is placed in front of the aileron, raised up. At the part of the wing, which is placed in front of the lowered aileron, the lifting force increases. Thus, a force moment is formed, which modifies the speed of rotation of the aircraft around an axis identical to the longitudinal axis of the machine.
History
Where did the aileron first appear? This amazing device was installed on a monoplane created in 1902 by the innovator Richard Percy from New Zealand. Unfortunately, his car made only very unstable and short flights. The first aircraft to make a perfectly coordinated roll flight was the 14 Bis, built by Alberto Santos-Dumont. Beforethe aerodynamic controls replaced the Wright brothers' wing distortion.
So, let's study the aileron further. This device has many advantages. The control surface that combines the flaps and roll rudders is called the flaperon. In order for the ailerons to imitate the function of the extended flaps, they are simultaneously lowered down. For long-term roll control, a simple differential turn is added to this deviation.
To adjust the tilt of liners with the above layout, a modified thrust vector of motors, gas rudders, spoilers, rudder, transformation of the center of mass of the aircraft, differential displacement of altitude rudders and other tricks can also be used.
Side effects
How does the aileron work? This is a capricious mechanism that has some drawbacks. One of the side effects of its action is a slight yaw in the opposite direction. In other words, when using the ailerons to turn to the right, the aircraft may move slightly to the left at the time of the increase in bank. This effect appears due to the difference in drag between the left and right wing panels, caused by the change in lift when the ailerons oscillate.
The wing console, in which the aileron is deflected down, has a large coefficient of drag. In the current control systems of "iron birds" this side effect is reduced by various methods. For example, in order to create a roll, the ailerons are also displaced inopposite side, but at unequal angles.
Reverse effect
Agree, the control of the aircraft requires skill. So, on high-speed cars with a significantly elongated wing, the effect of reverse roll rudders can be noticed. What does he look like?
If the deflection of an aileron located close to the wingtip causes a maneuvering load, the aircraft wing turns out and the angle of attack on it deviates. Such events can smooth out the effect of aileron displacement, or they can lead to the opposite result.
For example, if it is necessary to increase the lift force of the half-wing, the aileron deviates downward. Further, an upward force begins to act on the trailing edge of the wing, the wing turns forward, and the angle of attack on it decreases, which reduces lift. In fact, the effect of the roll rudders on the wing during reverse is similar to the effect of a trimmer on them.
One way or another, the reverse of the roll rudders was found on many jet aircraft (especially on the Tu-134). By the way, on the Tu-22, because of this effect, the maximum Mach number was reduced to 1.4. In general, pilots study aileron control for a long time. The most common methods to prevent roll reversal are the use of spoiler ailerons (the spoilers are located near the center of the wing chord and practically do not cause it to twist when released) or the installation of additional ailerons near the center section. If the second option is present, external (located near the tips) roll rudders needed for productive control onlow speeds are turned off at high speeds, and lateral control is carried out by internal ailerons, which do not reverse due to the impressive rigidity of the wing present in the center section.
Control systems
And now consider the control of the aircraft. A group of on-board vehicles that guarantee the regulation of the movement of "steel birds" is called the control system. Since the pilot is located in the cockpit, and the rudders and ailerons are located on the wings and tail of the aircraft, a constructive connection is established between them. It is her responsibility to ensure the reliability, ease and efficiency of control of the position of the machine.
Of course, when the coordinating surfaces are displaced, the force affecting them increases. However, this should not lead to an unacceptable increase in tension on the adjustment levers.
The aircraft control mode can be automatic, semi-automatic and manual. If a person makes the piloting instruments work with the help of muscular strength, then such a control system is called manual (direct regulation of the liner).
Systems with manual administration can be hydromechanical and mechanical. In fact, we have found that the wing of an aircraft plays an important role in handling. On civil aviation machines, basic adjustment is carried out by two pilots using kinematic devices that regulate forces and movements, command double levers, mechanical wiring and control surfaces.
If the pilot controls the machine with the help of mechanisms anddevices that ensure and improve the quality of the piloting process, then the control system is called semi-automatic. Thanks to the automatic system, the pilot only controls a group of self-acting parts that creates and changes the coordinating forces and factors.
Complex
The liner's basic control means is a complex of on-board devices and structures, with the help of which the pilot activates the adjustment means that change the flight mode or balance the car in a given mode. This includes rudders, ailerons, adjustable stabilizer. Elements that guarantee the adjustment of additional control details (flaps, spoilers, slats) are called wing lift or auxiliary control.
The liner's basic coordination system includes:
- command levers that the pilot acts on by moving them and applying force to them;
- special mechanisms, executive and automatic devices;
- pilot wiring connecting basic control systems to command levers.
Performing governance
The pilot performs longitudinal control, that is, changes the pitch angle, deflecting the control column away from himself or towards himself. By turning the steering wheel left or right and deflecting the ailerons, the pilot implements lateral control, tilting the car in the right direction. To move the rudder, the pilot presses the pedals, which are also used to control the nose landing gear while the liner is moving on the ground.
In general, the pilot is the main link in the manual and semi-automatic control systems, and the flaps, ailerons and other parts of the aircraft are just a way to move. The pilot perceives and processes information about the position of the car and rudders, existing overloads, develops a decision and acts on the command levers.
Requirements
Basic aircraft control must meet the following requirements:
- When controlling the machine, the movements of the pilot's legs and arms, necessary to shift the command levers, must coincide with the natural human reflexes that appear when maintaining balance. Moving the command stick in the right direction should cause the "steel bird" to move in the same direction.
- The reaction of the liner to the displacement of the command levers should have a slight delay.
- At the moment of deviation of the control instruments (rudders, ailerons, etc.), the forces applied to the command handles must increase smoothly: they must be directed in the direction opposite to the movement of the handles, and the amount of labor must be coordinated with the flight mode of the machine. The latter helps the pilot to get a "feeling of control" of the aircraft.
- The rudders must act independently of each other: deviation, for example, of the elevator cannot cause aileron deflection, and vice versa.
- The offset angles of the steering surfaces are required to ensure the likelihood of the car flying in all required takeoff and landing modes.
We hope this article helped you understand the purpose of the ailerons and understandbasic management of "steel birds".
