The main parts of the aircraft. Airplane arrangement

The invention of the aircraft allowed not only to realize the oldest dream of mankind - conquer the sky, but also to create the fastest mode of transport. Unlike air balloons and airships, aircraft are not much dependent on the vagaries of the weather, they are able to overcome large distances at high speed. The components of the aircraft consist of the following design groups: the wing, fuselage, tail, landing equipment, power plant, control systems, various equipment.

Operating principle

Aircraft - aircraft (LA) heavier than air, equipped with a power plant. With the help of this most important part of the aircraft, the thrust necessary for the flight is the acting (driving) force that the motor (air propeller or jet engine) develops on the ground or in flight . If the screw is located in front of the engine, it is called pulling, and if behind - pushing. Thus, the engine generates the forward motion of the aircraft relative to the environment (air). Accordingly, the wing, which creates a lift as a result of this translational movement, also moves relative to the air. Therefore, the device can stay in the air only if there is a certain speed of flight.

What are the parts of the aircraft called

The body consists of the following main parts:

• The fuselage is the main body of the aircraft, connecting the wings (wing), plumage, power system, chassis and other components into one whole. The fuselage accommodates the crew, passengers (in civil aviation), equipment, payload. Fuel, chassis, motors, etc. can also be placed (not always)
• The engines are used to drive the aircraft.
• The wing is a working surface designed to create a lifting force.
• Vertical tail is designed for controllability, balancing and stability of the aircraft relative to the vertical axis.
• Horizontal tail is designed for controllability, balancing and stability of the aircraft relative to the horizontal axis.

Wings and fuselage

The main part of the aircraft is a wing. It creates the conditions for fulfilling the main requirement for the possibility of flight-the presence of a lift. The wing is attached to the body (fuselage), which can have one or another shape, but with minimal aerodynamic resistance if possible. To do this, it is conveniently provided with a streamlined droplet shape.

The front of the aircraft serves to accommodate the cockpit and the radar systems. In the rear part is the so-called tail empennage. It serves to provide controllability during the flight.

Construction of a feather

Consider an average aircraft, the tail part of which is made according to the classical scheme, typical for most military and civilian models. In this case, the horizontal plumage will include a fixed part - the stabilizer (from the Latin Stabilis, stable) and the movable one - the elevator.

The stabilizer serves to give the stability of the aircraft relative to the transverse axis. If the nose of the aircraft descends, then, respectively, the tail of the fuselage, together with the feathers, will rise upward. In this case, the air pressure on the upper surface of the stabilizer will increase. The created pressure will return the stabilizer (respectively, and the fuselage) to its original position. When lifting the nose of the fuselage upward, the airflow pressure will increase on the lower surface of the stabilizer, and it will return to its original position. Thus, automatic (without pilot intervention) is provided for the stability of the aircraft in its longitudinal plane with respect to the transverse axis.

The back of the aircraft also includes vertical tail. Similarly to the horizontal, it consists of a fixed part - the keel, and a movable - the rudder. The keel gives stability to the aircraft in relation to its vertical axis in the horizontal plane. The principle of action of the keel is similar to the action of the stabilizer - when the nose is turned to the left, the keel deviates to the right, the pressure on its right plane increases and returns the keel (and the entire fuselage) to its previous position.

Thus, relative to the two axes, flight stability is ensured by feathering. But there was still one axis - longitudinal. To provide automatic stability of movement relative to this axis (in the transverse plane), the wing fenders of the glider are placed not horizontally, but at some angle relative to each other so that the ends of the arms are deflected upwards. This arrangement resembles the letter "V".

Control systems

Steering surfaces are important parts of an aircraft designed to control an aircraft. These include ailerons, rudders and heights. Control is provided with respect to the same three axes in the same three planes.

The elevator is the movable rear end of the stabilizer. If the stabilizer consists of two consoles, there are accordingly two elevator wheels that are deflected downward or upward, both synchronously. With its help, the pilot can change the altitude of the flight of the aircraft.

The rudder is the movable rear part of the keel. When it is deflected in one direction or another, an aerodynamic force appears on it, which rotates the aircraft relative to the vertical axis passing through the center of mass, in the opposite direction from the direction of deflection of the rudder. The rotation occurs until the pilot returns the rudder to a neutral (non-deflected position), and the LA will move in a new direction.

Ailerons (from the French Aile, wing) are the main parts of the aircraft, representing the moving parts of the wing consoles. Served to control the aircraft relative to the longitudinal axis (in the transverse plane). Since the consoles of the wing are two, there are also two ailerons. They work synchronously, but, unlike the elevator, they deviate not in one direction, but in different directions. If one aileron is tilted up, then the other is down. On the wing console, where the aileron is deflected upwards, the lift force is reduced, and where it is downwards - increases. And the fuselage of the aircraft rotates in the direction of the raised aileron.

Engines

All aircraft are equipped with a power plant, allowing to develop speed, and, therefore, to ensure the occurrence of lift. The engines can be located at the rear of the aircraft (typical for jet aircraft), in front (light vehicles) and on the wings (civil aircraft, transport vehicles, bombers).

They are divided into:

• Reactive - turbojet, pulsating, two-circuit, direct flow.
• Screw - piston (screw-motor), turboprop.
• Missile - liquid, solid fuel.

Other systems

Of course, other parts of the aircraft are also important. Chassis allow aircraft to take off and land from equipped aerodromes. There are amphibious aircraft, where instead of the chassis special floats are used - they allow take-off and landing at any place where there is a pond (sea, river, lake). Known models of light-engine aircraft, equipped with skis, for operation in areas with a stable snow cover.

Modern aircraft are crammed with electronic equipment, communication devices and information transfer. Military aircraft use sophisticated weapons systems, detection of targets and suppression of signals.

Classification

By appointment, planes are divided into two large groups: civilian and military. The main parts of the passenger aircraft are distinguished by the presence of an equipped passenger compartment, occupying most of the fuselage. A distinctive feature are the portholes on the sides of the hull.

Civilian aircraft are subdivided into:

• Passenger - local airlines, main near (range less than 2000 km), medium (range less than 4000 km), distant (range less than 9000 km) and intercontinental (range more than 11 000 km).
• Freight - light (weight of cargo up to 10 tons), medium (weight of cargo up to 40 tons) and heavy (weight of cargo more than 40 tons).
• Special purpose - sanitary, agricultural, reconnaissance (ice reconnaissance, fish-breeding), fire-fighting, for aerial photography.
• Educational.

Unlike civilian models, military aircraft do not have a comfortable cabin with portholes. The main part of the fuselage is occupied by weapons systems, reconnaissance equipment, communications, engines and other units.

By appointment, modern military aircraft (given the combat missions they perform), can be divided into the following types: fighters, ground attack planes, bombers (missile carriers), scouts, military transport, special and auxiliary purposes.

Airplane arrangement

The device of aircraft depends on the aerodynamic scheme, on which they are executed. The aerodynamic scheme is characterized by the number of basic elements and the location of the bearing surfaces. If the nose of the aircraft in most models is similar, then the location and geometry of the wings and tail can vary greatly.

There are the following schemes of the aircraft:

• "Classical".
• "The flying wing."
• "Duck".
• "The tailless."
• "Tandem".
• Convertible circuit.
• Combined circuit.

Aircraft made in accordance with the classical scheme

Consider the main parts of the aircraft and their purpose. The classical (normal) arrangement of nodes and aggregates is typical for most of the world's apparatuses, whether military or civilian. The main element - the wing - works in a pure unperturbed flow, which flows smoothly around the wing and creates a certain lifting force.

The nose part of the aircraft is shortened, which leads to a reduction in the required area (and consequently, the mass) of the vertical tail. This is because the forward part of the fuselage causes a destabilizing travel time relative to the vertical axis of the aircraft. Reducing the forward portion of the fuselage improves the view of the front hemisphere.

Disadvantages of the normal scheme are:

• The operation of the horizontal tail (GO) in the tapered and perturbed flow significantly reduces its efficiency, which necessitates the use of plumage of a larger area (and, consequently, of the mass).
• To ensure the stability of flight, vertical tail (BO) should create a negative lift, that is, directed downward. This reduces the overall efficiency of the aircraft: from the magnitude of the lifting force that the wing creates, it is necessary to take away the force that is created on the GO. To neutralize this phenomenon, a wing of an enlarged area (and, consequently, also of mass) should be used.

Arrangement of an airplane according to the "duck" scheme

With this design, the main parts of the aircraft are placed differently than in the "classic" models. First of all, the changes touched the horizontal plumage line. It is located in front of the wing. According to this scheme, the first Wright brothers built their first plane.

Benefits:

• Vertical tail operates in undisturbed flow, which increases its efficiency.
• To ensure the stability of the flight, the tail creates a positive lift, that is, it is added to the lifting force of the wing. This allows you to reduce its area and, accordingly, the mass.
• Natural "protivoshtornaya" protection: the possibility of transferring wings to the supercritical angles of attack for "ducks" is excluded. The stabilizer is set so that it receives a larger angle of attack than the wing.
• Moving the focus of the aircraft back with increasing speed in the "duck" scheme occurs to a lesser degree than with the classical layout. This leads to less changes in the degree of longitudinal static stability of the aircraft, which in turn simplifies the characteristics of its control.

Disadvantages of the "duck" scheme:

• When the flow is broken at the plumage, not only the aircraft exit to smaller angles of attack occurs, but also its "subsidence" due to the reduction of its overall lift. This is especially dangerous in takeoff and landing modes because of the proximity of the earth.
• The presence in the nose of the fuselage of the feathering mechanisms worsens the view of the lower hemisphere.
• To reduce the area of the forward GO, the length of the forward part of the fuselage is considerable. This leads to an increase in the destabilizing moment relative to the vertical axis, and, accordingly, to an increase in the area and mass of the structure.

Planes made in accordance with the "tailless" scheme

In models of this type, there is no important, familiar part of the aircraft. A photo of flying machines "tailless" ("Concord", "Mirage", "Vulcan") shows that they do not have horizontal plumage. The main advantages of such a scheme are:

• Reduction of the wind drag, which is especially important for aircraft with high speed, in particular, cruising. At the same time, fuel costs are reduced.
• The high rigidity of the wing on torsion, which improves its characteristics of aeroelasticity, achieves high maneuverability characteristics.

Disadvantages:

• For balancing on some flight modes, part of the mechanization of the trailing edge of the wing (flaps) and the steering surfaces must be deflected upwards, which reduces the overall lift of the aircraft.
• The combination of the control elements of the aircraft relative to the horizontal and longitudinal axes (due to the lack of elevator) degrades the characteristics of its controllability. The absence of a specialized tail causes the steering surfaces to be on the trailing edge of the wing, perform (if necessary) the duties of both ailerons and elevator controls. These steering surfaces are called Elevons.
• Using a part of the means of mechanization to balance the airplane worsens its takeoff and landing characteristics.

"Flying Wing"

In this scheme, in fact, there is no such part of the aircraft as the fuselage. All the volumes needed to accommodate the crew, payload, engines, fuel, equipment are in the middle of the wing. Such a scheme has the following advantages:

• Least aerodynamic resistance.
• The smallest weight of the structure. In this case, the whole mass is on the wing.
• Since the aircraft's longitudinal dimensions are small (due to the lack of a fuselage), the destabilizing moment relative to its vertical axis is negligible. This allows designers to either significantly reduce the area of the VO, or even abandon it altogether (in birds, as is known, vertical tail is absent).

The disadvantages include the complexity of ensuring the sustainability of flight LA.

"Tandem"

The "tandem" scheme, when two wings are located one after another, is infrequent. This solution is used to increase the wing area at the same values of its span and the length of the fuselage. This reduces the specific load on the wing. Disadvantages of such a scheme is a large aerodynamic resistance, an increase in the moment of inertia, especially with respect to the transverse axis of the aircraft. In addition, as the speed of the flight increases, the longitudinal balancing characteristics of the aircraft change. Steering surfaces on such aircraft can be located either directly on the wings or on the tail.

Combined circuit

In this case, the component parts of the aircraft can be combined using different design schemes. For example, the horizontal plumage is provided for both the nose and the tail of the fuselage. They can be used so-called direct control of the lifting force.

In this case, the nose horizontal plumage together with the flaps create an additional lifting force. The moment of pitch that occurs in this case will be aimed at increasing the angle of attack (the nose of the aircraft rises). To parry this point, the tail fin must create a moment to reduce the angle of attack (the nose of the aircraft is lowered). For this, the force on the tail part must also be directed upwards. That is, there is an increase in the lifting force on the nose GO, on the wing and on the tail GO (and consequently, on the whole aircraft) without turning it in the longitudinal plane. In this case, the aircraft simply rises without any evolution relative to its center of mass. Conversely, with such an aerodynamic arrangement of the aircraft, it can carry out evolution with respect to the center of mass in the longitudinal plane without changing its flight trajectory.

The ability to carry out such maneuvers significantly improves the tactical and technical characteristics of maneuverable aircraft. Especially in combination with the direct control of the lateral force, for the implementation of which the aircraft must have not only the tail, but also the nose longitudinal plumage.

Convertible circuit

The construction of the aircraft, built on a convertible scheme, is distinguished by the presence of a destabilizer in the forward part of the fuselage. The function of destabilizers is a reduction in certain limits, or even a complete elimination of the displacement of the aerodynamic focus of the aircraft on supersonic flight regimes. This increases the maneuverability of the aircraft (which is important for the fighter) and increases the range or reduces fuel consumption (this is important for supersonic passenger aircraft).

Destabilizers can also be used in take-off / landing modes to compensate for the dive moment, which is caused by a deflection of the landing gear (flaps, flaps) or the nose of the fuselage. On subsonic flight modes, the destabilizer hides in the middle of the fuselage or is set to the weathervane mode (it is freely oriented along the flow).