What are the planes. Civil aviation aircraft with straight and trapezoidal wings

The main units of the aircraft

Airplanes are heavier-than-air aircraft, they are characterized by the aerodynamic principle of flight. Airplanes have lift Y is created due to the energy of the air flow, washing the bearing surface, which is fixed relative to the body, and translational motion in a given direction is provided by the thrust of the power plant (PU) of the aircraft.

Different types of aircraft have the same main units (components): wing , vertical (VO) and horizontal (GO) plumage , fuselage , power plant (SU) and chassis (Figure 2.1).

Rice. 2.1. The main structural elements of the aircraft

Aircraft wing1 creates lift and provides lateral stability to the aircraft during its flight.

often the wing is a power base for placing the landing gear, engines, and its internal volumes are used to accommodate fuel, equipment, various components and assemblies of functional systems.

For improvement takeoff and landing characteristics(VPH) of modern aircraft, mechanization equipment is installed on the wing along the leading and trailing edges. On the leading edge of the wing is placed slats , and on the back - flaps10 , spoilers12 And aileron spoilers .

In terms of power, the wing is a beam of complex design, the supports of which are the power frames of the fuselage.

Ailerons11 are cross-government bodies. They provide lateral control of the aircraft.

Depending on the scheme and flight speed, geometric parameters, structural materials and structural power scheme, the mass of the wing can be up to 9 ... 14 % from the takeoff weight of the aircraft.

Fuselage13 combines the main units of the aircraft into a single whole, i.e. provides a circuit for the power circuit of the aircraft.

The internal volume of the fuselage is used to accommodate the crew, passengers, cargo, equipment, mail, baggage, rescue equipment in case of emergencies. Cargo aircraft fuselages are equipped with advanced loading and unloading systems, devices for fast and reliable cargo mooring.

The function of the fuselage of seaplanes is performed by a boat, which allows you to take off and land on the water.

the fuselage in terms of force is a thin-walled beam, the supports of which are the wing spars, with which it is connected through the nodes of the power frames.

the mass of the fuselage structure is 9…15 % from the takeoff weight of the aircraft.

Vertical plumage5 consists of a fixed part keel4 And rudder (RN) 7 .

Keel 4 provides the aircraft with directional stability in the plane X0Z, and РН - directional controllability about the axis 0y.

Trimmer RN 6 ensures the removal of prolonged loads from the pedals, for example, in the event of an engine failure.

Horizontal tail9 includes a fixed or limited movable part ( stabilizer2 ) and the moving part - elevator (RV) 3 .

Stabilizer 2 gives the aircraft longitudinal stability, and RV 3 - longitudinal controllability. RV can carry a trimmer 8 to unload the steering column.

Weight, structures of GO and VO usually do not exceed 1.3 ... 3 % from the takeoff weight of the aircraft.

Chassis aircraft 16 refers to takeoff and landing devices (TLU), which provide takeoff, takeoff, landing, run and maneuvering of the aircraft when moving on the ground.

The number of supports and their relative position center of gravity (CM) of the aircraft depends on the chassis layouts and the characteristics of the operation of the aircraft.

The landing gear of the aircraft shown in Fig. 2.1 has two main supports16 and one bow support17 . Each support includes a power rack18 and supporting elements wheels15 . Each support can have several racks and several wheels.

Most often, the landing gear of an aircraft is made retractable in flight, therefore, special compartments in the fuselage are provided for its placement. 13. It is possible to clean and place the main landing gear in special gondolas (or engine nacelles), fairings14 .

The chassis ensures the absorption of the kinetic energy of impact during landing and braking energy during the run, taxiing and maneuvering the aircraft on the airfield.

amphibious aircraft can take off and land both from ground airfields and from the water surface.

Fig.2.2. Amphibious aircraft landing gear.

on the body seaplane install a wheeled chassis, and place under the wing floats1 ,2 (fig.2.2).

The relative mass of the chassis is usually 4…6 % from the takeoff weight of the aircraft.

Power point 19 (see Fig. 2.1), provides the creation of aircraft thrust. It consists of engines, as well as systems and devices that ensure their operation in flight and ground operation of the aircraft.

For piston engines, the thrust force is created by a propeller, for turboprops - by a propeller and partly by the reaction of gases, for jet engines - by the reaction of gases.

CS includes: engine attachment points, nacelle, CS control, engine input and output devices, fuel and oil systems, engine start systems, fire and anti-icing systems.

The relative mass of the control system, depending on the type of engines and their layout on the aircraft, can reach 14 ... 18 % from the takeoff weight of the aircraft.

2.2. Technical, economic and flight technical
aircraft characteristics

The technical and economic characteristics of the aircraft are:

Relative payload mass:

`m mon = m Mon /m 0

Where m mon - payload mass;

m 0 - aircraft takeoff weight;

Relative mass of the maximum paid load:

`m knmax = m knmax / m 0

Where m knmax mass of maximum payload;

Maximum hourly output:

P h = m knmax ∙ v flight

Where v flight - flight speed of the aircraft;

Fuel consumption per unit of productivity q T

The main flight performance characteristics of aircraft include:

Maximum cruising speed v cr.max;

cruising economic speed V to p .ek;

Cruise altitude H to p;

Flight range with maximum paid load L;

Average lift-to-drag ratio TO in flight;

rate of climb;

Carrying capacity, which is determined by the mass of passengers, cargo, baggage carried on an aircraft for a given flight mass and fuel supply;

Takeoff and landing characteristics (TLC) of the aircraft.

The main parameters characterizing the airborne landing are the approach speed - V z.p.; landing speed - V P; take-off speed - V omp; takeoff run length l once; landing run length - l np; the maximum value of the lift coefficient in the landing configuration of the wing - WITH y max n;maximum value of the lift coefficient in the takeoff configuration of the wing WITH at max vzl

Aircraft classification

Classification of aircraft is carried out according to many criteria.

One of the main criteria for classifying aircraft is appointment criterion . this criterion predetermines the flight performance, geometric parameters, layout and composition of the functional systems of the aircraft.

According to their purpose, aircraft are divided into civil And military . Both the first and second aircraft are classified depending on the type of tasks performed.

The classification of civil aircraft only is considered below.

Civil aircraft designed to transport passengers, mail, cargo, as well as to solve a variety of economic problems.

Aircraft are divided into passenger , cargo , experimental , training , as well as aircraft target national economic purpose .

Passenger aircraft, depending on the flight range and carrying capacity, are divided into:

- long haul aircraft - range of flight L>6000 km;

- medium haul aircraft - 2500 < L < 6000 км;

- short haul aircraft - 1000< L < 2500 км;

- aircraft for local airlines (MVL) - L <1000 км.

long haul aircraft(Fig. 2.3) with a flight range of more than 6000 km are usually equipped with a control system of four turbofan engines or propfan engines, which makes it possible to increase flight safety in the event of failure of one or two engines.

Medium haul aircraft(Fig. 2.4, Fig. 2.5) have a control system of two or three engines.

Short haul aircraft(Fig. 2.6) with a flight range of up to 2500 km, they have a control system of two or three engines.

Aircraft of local airlines (LA) are operated on air routes with a length of less than 1000 km, and their control system can consist of two, three or even four engines. The increase in the number of engines to four is due to the desire to ensure a high level of flight safety with a high intensity of takeoffs and landings, typical for international aircraft.

MVL aircraft include administrative aircraft, which are designed to carry 4 ... 12 passengers.

Cargo aircraft provide transportation of goods. These aircraft, depending on the flight range and carrying capacity, can be subdivided similarly to passenger ones. transportation of goods can be carried out both inside the cargo compartment (Fig. 2.7) and on the external sling of the fuselage (Fig. 2.8).

Training aircraft provide training and training for flight personnel in educational institutions and civil aviation training centers (Fig. 2.9) Such aircraft are often made double (instructor and trainee)

experimental aircraft are created to solve specific scientific problems, to conduct full-scale research directly in flight, when it is necessary to verify hypotheses and constructive solutions.

Aircraft for national economy depending on the intended use, they are divided into agricultural, patrol, observations of oil and gas pipelines, forests, coastal zone, traffic, sanitary, ice reconnaissance, aerial photography, etc.

Along with aircraft specially designed for these purposes, small-capacity MVL aircraft can be re-equipped for specific tasks.

Rice. 2.7. Cargo airplane

Rice. 2.10

Rice. 2.9

Fig.2.8

Rice. 2.8. Transportation of goods on an external sling

Rice. 2.9. Trainer aircraft

Rice. 2.10. Aircraft of national economic purpose

Aerodynamic layout aircraft characterizes the number, external shape of the bearing surfaces and the relative position of the wing, tail and fuselage.

The classification of aerodynamic layouts is based on two features:

- wing shape ;

- plumage arrangement I.

In accordance with the first sign, six types of aerodynamic configurations are distinguished:

- with a straight and trapezoidal wing;

- with swept wing;

- with a delta wing;

- with a straight wing of small elongation;

- with an annular wing;

- with round wing.

For modern civil aircraft, the first two and partly the third type of aerodynamic configurations are practically used.

According to the second type of classification, the following three options for aerodynamic layouts of aircraft are distinguished:

Normal (classical) scheme;

Schemes "duck";

Tailless scheme.

A variation of the "tailless" scheme is the "flying wing" scheme.

Aircraft normal circuit (see fig. 2.5, 2.6) have GO located behind the wing. This scheme has become dominant on civil aviation aircraft.

The main advantages of the normal circuit:

Possibility of effective use of wing mechanization;

Easy balancing of the aircraft with extended flaps;

Reducing the length of the forward fuselage. This improves the pilot's view and reduces the airfoil area, since the shortened forward fuselage causes less destabilizing ground moment;

The possibility of reducing the areas of VO and GO, since the shoulders of GO and VO are much larger than those of other schemes.

disadvantages of the normal scheme:

GO creates negative lift in almost all flight modes. This leads to a decrease in the lift force of the aircraft. Especially in transitional flight conditions during takeoff and landing;

GO is located in the disturbed air flow behind the wing, which adversely affects its operation.

To remove the GO from the "aerodynamic shadow" of the wing or from the "wake" of the flaps in transitional flight modes, it is shifted relative to the wing in height (Fig. 2.11, a), it is carried out to the middle of the keel (Fig. 2.11; b) or to the top of the keel (Fig. 2.11, c).

Rice. 2.12

Rice. 2.11

Rice. 2.11 Horizontal tail layouts

A. VO., offset relative to the wing in height;

b. VO is located in the middle of the keel (cruciform plumage);

V. T-shaped plumage;

g. v - figurative plumage.

In the practice of aircraft construction, there are known cases of using a combined, so-called v-tail (Fig. 2.12). the functions of GO and VO in this case are performed by two surfaces spaced at an angle relative to each other. The rudders placed on these surfaces, with a synchronous up and down deflection, work as a RV, and when one rudder is deflected up and the other down, the aircraft is steered in directional respect.

Quite often, a two-keel and even a three-keel air defense can be used on aircraft.

With the aerodynamic layout of the aircraft according to duck pattern on GO they are placed in front of the wing on the forward part of the fuselage (Fig. 2.13)

The advantages of the "duck" scheme are:

Placement of GO in an undisturbed air flow;

The possibility of reducing the size of the wing, since the GO becomes a carrier, i.e. participates in the creation of the lifting force of the aircraft;

Sufficiently easy parrying of the emerging diving moment when the mechanization of the wing is deflected by the deflection of the GO;

Rice. 2.13 The layout of the aircraft according to the scheme "duck"

An increase in the GO shoulder by more than 30% than in the normal scheme, which makes it possible to reduce the wing area;

When high angles of attack are reached, the flow stall on the GO occurs earlier than on the wing, which practically eliminates the risk of the aircraft reaching supercritical angles of attack and stalling it into a tailspin.

For an aircraft made according to the "duck" scheme, the shift of the focus position back when moving from M<1 к М>1 is less than that of normal aircraft, so the increase in the degree of longitudinal stability is observed to a lesser extent.

The disadvantages of this scheme are:

Reducing the bearing capacity of the wing by 10-15 % due to the bevel of the flow from the GO;

A relatively small arm of the VO, leading to an increase in the area of the VO, and sometimes to the installation of two keels to increase directional stability. This compensates for the destabilizing moment created by the elongated forward fuselage.

Tailless scheme is characterized by the absence of GO (see Fig. 1.13), while the functions of GO are shifted to the wing. Aircraft made according to this scheme may not have a fuselage, in which case they are called a "flying wing". Such aircraft are characterized by minimal drag.

The tailless scheme has the following advantages:

Since triangular wings are used on such aircraft, with large dimensions of the onboard rib, it is possible to reduce the relative thickness of the profile, ensuring the rational use of the wing volume for fuel placement;

The absence of GO loads makes it possible to lighten the tail section of the fuselage;

The cost and weight of the airframe are reduced, since there is no GO, for the same reason, the frictional resistance of the aircraft decreases due to a decrease in the area of the surface streamlined by the air flow;

Significant geometric dimensions of the onboard rib provide the ability to create the effect of "air cushion" in the landing mode of the aircraft;

Since double swept wings are used in the "tailless" scheme, a significant increase in the lift coefficient occurs during takeoff.

Among the shortcomings of this scheme, the most significant are:

Impossibility of full use of the bearing capacity of the wing on landing;

Reducing the aircraft ceiling due to a decrease in aerodynamic quality, which is explained by holding the elevons in the upper deflected position to achieve the highest angle of attack of the wing;

Difficulty, and sometimes the impossibility of balancing the aircraft with the flaps extended;

It is difficult to ensure the directional stability of the aircraft due to the small shoulder of the VO, therefore, sometimes three keels are installed (see Fig. 1.13).

In the practice of experimental aircraft construction, you can find options with a combination of basic schemes in one aircraft.

A variant is possible when two GOs are used on the aircraft - one in front of the wing and the second behind it. When implementing the "tandem" scheme, the aircraft has a wing and GO that are almost commensurate in area. The "tandem" scheme can be considered as an intermediate between the normal scheme and the "duck" scheme, due to which the operational range of balance of balance is expanded with relatively small losses in the aerodynamic quality for balancing the aircraft.

The main design features by which aircraft are classified are:

Number and arrangement of wings;

Fuselage type;

Type of engines, number and placement of them on the aircraft;

Chassis scheme, characterized by the number of supports and their relative position relative to the aircraft CM.

Depending on the number of wings, monoplanes and biplanes are distinguished.

Scheme monoplane dominates in aircraft construction, and most aircraft are made according to this scheme, which is due to the lower drag of the monoplane and the possibility of increasing the increase in flight speeds.

Planes scheme "biplane" (Fig. 2.16) are distinguished by high
maneuverability, but they are low-speed, so this scheme is implemented for special-purpose aircraft, for example, for agricultural ones.

Figure 2. 16 Biplane aircraft

According to the location of the wing relative to the fuselage, aircraft can be operated according to the scheme "low-wing" (Fig. 2.17, a), "medium-wing" (Fig. 2.17, b) and "high-wing" (Fig. 2.17, c).

Fig.2.17. Various wing layouts

Scheme "low-wing" the least advantageous in terms of aerodynamics, since in the zone of junction of the wing with the fuselage, the smoothness of the flow is disturbed and additional resistance arises due to the interference of the wing-fuselage system. This disadvantage can be significantly reduced by setting fairings, ensuring the elimination of the diffuser effect.

The placement of the gas turbine engine in the root part of the wing makes it possible to use
ejector effect from the engine jet, which is called active fairing.

The low-wing aircraft has a higher location of the lower fuselage contour above the ground. This is due to the need to prevent the wing tip from touching the runway surface during a rolled landing, as well as to ensure the safe operation of the control system when placing engines on the wing. In this case, the process of unloading and loading cargo, luggage, as well as boarding and disembarking passengers becomes more complicated. This shortcoming can be avoided by equipping the landing gear of the aircraft with a "squat" mechanism.

The "low-wing" scheme is most often used for passenger aircraft, as it provides greater safety compared to other options for emergency landing on soil and water. During an emergency landing on the ground with the landing gear retracted, the wing absorbs the impact energy, protecting the passenger cabin. When landing on water, the aircraft is immersed in water up to the wing, which gives the fuselage additional buoyancy and simplifies the organization of work related to the evacuation of passengers.

An important advantage of the "low-wing" scheme is the smallest mass of the structure, since the main landing gear is most often associated with the wing and their dimensions and weight are less than those of a high-wing. Compared to a high-wing aircraft with a landing gear on the fuselage, a low-wing aircraft has a lower mass, since it does not require weighting of the fuselage associated with attaching the main landing gear to it.

The low-wing aircraft with the placement of the main supports on the wing retains the basic rule: the aircraft is supported by the bearing surface. This rule is maintained in all operational modes, both in flight and during takeoff and landing. The wing in the latter case rests on the chassis during the run and run. Thanks to this, it is possible to unify the power circuit, which determines the ways of transferring maximum loads, and to reduce the weight of the aircraft structure as a whole. The considered advantages have become the reason for the dominant position of the "low-wing" scheme on passenger aircraft.

Scheme "medium plan" (Fig. 2. 17, b) is most often not used for passenger and cargo aircraft, since the wing box (its power section) cannot be placed in the passenger or cargo cabin.

With the growth of take-off masses and aircraft parameters, it becomes possible to bring the wing layout of wide-body aircraft closer to the mid-plane. The wing in this case is raised to the level of the floor of the passenger cabin or cargo compartment, as is done on the A-300, Boeing-747, Il-96, etc. Thanks to this solution, it is possible to significantly improve aerodynamic characteristics.

In its pure form, the "medium-plan" scheme can be implemented on double-deck aircraft, where the wing practically does not interfere with the use of fuselage volumes for accommodating passenger compartments, cargo spaces and equipment.

The "high-wing" scheme (Fig. 2.17, c) is widely used for cargo aircraft, and also finds application on MVL aircraft. In this case, it is possible to obtain the smallest distance from the lower contour of the fuselage to the runway surface, since the high wing does not affect the choice of the height of the fuselage relative to the ground.

When using schema "high-wing" there is a possibility of free maneuvering of special vehicles during aircraft maintenance.

The transport efficiency of cargo aircraft is increased due to the lowest position of the cargo compartment floor, which allows for quick and easy loading and unloading of bulky cargo, self-propelled equipment, various modules, etc.

The resource of engines increases, since they are located at a considerable distance from the ground and the probability of solid particles from the runway surface entering the air intakes is sharply reduced.

The noted advantages of the high-wing aircraft explain the dominant position that this scheme has taken on transport aircraft in the domestic (An-22, An-124, An-225), foreign (C-141, C-5A, C-17 (USA) and others .) practice.

The "high-wing" scheme easily provides a rated safe distance from the runway surface to the end of the propeller blade or the lower contour of the GTE air intake. This explains the rather frequent use of this scheme on MVL passenger aircraft (An-28 (Ukraine), F-27 (Holland), Short-360 (England), ATP 42, ATP-72 (France-Italy)).

The undoubted advantage of the "high-wing" scheme is a higher value WITH at max due to the preservation of a completely or partially aerodynamically clean upper surface of the wing above the fuselage, greater efficiency of wing mechanization by reducing the end effect on the flaps, since the fuselage side and the engine nacelle play the role of end washers.

However, the large mass of the airframe structure in comparison with other schemes adversely affects either the payload, or the fuel supply and flight range. The weighting of the airframe structure is explained by:

The need to increase the area of VO by 15-20 % due to part of it getting into the shading zone from the wing;

An increase in the mass of the fuselage by 15-20 % due to an increase in the number of reinforced frames in the attachment area of the main landing gear, strengthening the structure of the lower fuselage contour area in case of an emergency landing with the landing gear not extended, and due to hardening of the pressurized cabin.

When attaching the main landing gear to the power base of the fuselage, there are difficulties in providing the required gauge.

The small track of the chassis increases the load on one concrete slab,
which may require a higher aerodrome class to operate the aircraft.

The desire to provide an acceptable gauge often makes it necessary to increase the overall width of the reinforced frames in the area where the main supports are located, to form protruding landing gear nacelles and to increase the midsection of the aircraft, and hence its aerodynamic drag. As statistics show, in this case, the frontal resistance of the chassis nacelles can reach 10-15 % from the total resistance of the fuselage.

The lower safety of a high-wing aircraft during an emergency landing on water and land sometimes makes it impossible to use this scheme on aircraft with a large passenger capacity, since during an emergency landing on the ground, the wing with its mass, together with the engines, tends to crush the fuselage and the passenger cabin. When landing on water, the fuselage sinks to the lower contours of the wing and the passenger cabin may be under water. In this case, the organization of work to rescue passengers is much more complicated and evacuation of people is possible only through emergency hatches in the upper part of the fuselage.

by fuselage type aircraft are divided into conventional ones, i.e. made according to a single-fuselage scheme (Fig. 2.18, a); according to the two-fuselage scheme and the "nacelle" scheme (Fig. 2.18, b).

Rice. 2.18 Classification of airplanes by fuselage type

The most widely used single-fuselage scheme, which allows to obtain the most advantageous configuration of the fuselage shape from an aerodynamic point of view, since the frontal resistance in this case will be the smallest compared to other types.

When placing the tail of the aircraft not on the fuselage, but on two beams (Fig. 2.18, b) or replacing the fuselage with a gondola, an increase in drag occurs. The "nacelle" scheme (Fig. 2.18, b) is characterized by poor streamlining of the nacelles, which can lead to aircraft instability at high angles of attack. Therefore, the two-beam "nacelle" scheme in the practice of aircraft construction is rarely implemented, mainly on transport aircraft, where issues of transport efficiency become paramount. An example of such a solution is the Argosy cargo aircraft from Hawker Sidley.

Fig. 2.19 Aircraft "Adgie Aircraft"

By engine type distinguish between aircraft with PD, turbojet, TVLD, etc.

By number of engines aircraft are divided into one-, two-, three-, four-, six-engine.

On passenger aircraft, from the condition of ensuring flight safety, the number of engines should not be less than two. An increase in the number of engines over six is unjustified due to the difficulties associated with ensuring the synchronization of the operation of individual control systems and the increase in time and labor intensity of maintenance work.

According to the location of the engines subsonic passenger aircraft can be classified into four main groups: engines - on the wing (Fig. 2.20, a), engines - in the root of the wing, engines - on the rear fuselage (b) and a mixed version (c) of the engine layout.

When choosing a place for installing engines, they take into account the features of the general layout of the aircraft, operating conditions and ensuring maximum engine life, strive to obtain the least frontal resistance of the control system, and minimize air losses in the air intakes.

So, on aircraft with three engines, it is advisable to use a mixed layout option (Fig. 2.20): two engines under the wing and a third one in the rear fuselage or on the keel.

Rice. 2.20 Aircraft engine layouts

On aircraft with two engines, the control system is placed on the wing or on the rear fuselage.

With an increase in the bypass ratio of the engine, its diameter increases. Therefore, when arranging the engines under the wing, it is necessary to increase the height of the chassis to ensure a normalized distance from the bypass of the engine nacelle to the ground. This leads to an increase in the mass of the aircraft structure and creates a number of problems related to passengers, baggage and maintenance. First of all, this applies to MVL aircraft, which are often operated from airfields that do not have special equipment. At the same time, the effect of unloading the wing in flight due to the placement of engines on it is significantly reduced, since with an increase in the bypass ratio, the specific gravity of the turbojet engine decreases.

Figure 2.21 shows two aircraft, the design of which was created on the basis of the same requirements for paid load, range, air-to-air ratio, fuselage midsection, etc. Figure 2.21 shows the difference between the two aircraft in terms of the height of the wing and fuselage relative to the ground.

Fig. 2.21 Effect of bypass engines on aircraft layout

By type of landing gear they are divided into wheeled, ski, float (for seaplanes), caterpillar and hovercraft chassis.

The predominant distribution was received by a wheeled chassis, and quite often a float is used.

According to the chassis diagram aircraft are divided into tricycle and
two-support.

The three-bearing scheme is carried out in two versions: a three-bearing scheme with a nose support and a three-bearing scheme with a tail support. In most cases, aircraft use tricycle with nose support. The second version of this scheme is found on light aircraft.

The two-bearing chassis scheme on civil aircraft is practically not used.

On heavy, especially transport, aircraft, a multi-support chassis scheme has become widespread. For example, on a Boeing-747 aircraft, a five-post landing gear is used, on an An-225 aircraft, a sixteen-post landing gear, and on a passenger Il-86, a four-post landing gear.

2.4. DESIGN REQUIREMENTS
AIRCRAFT

All requirements for the design of aircraft are divided into are common , mandatory for all airframe units, and special .

The general requirements include aerodynamic, strength and rigidity, reliability and survivability of aircraft, operational, maintainability, manufacturability of aircraft production, economic and requirements, minimum weight of the airframe structure and functional systems.

Aerodynamic requirements are reduced to ensuring that the influence of the aircraft shape, its geometric and design parameters correspond to the given flight data obtained at the lowest energy costs. The implementation of these requirements provides for ensuring the minimum resistance of the aircraft, the required characteristics of stability and controllability, high air handling characteristics, indicators of the cruising flight mode.

The fulfillment of aerodynamic requirements is achieved by choosing the optimal values of the parameters of individual units (parts) of the aircraft, their rational mutual layout and a high level of specific parameters.

Strength and stiffness requirements are presented to the airframe frame and its skin, which must withstand all types of operational loads without destruction, while deformations should not lead to a change in the aerodynamic properties of the aircraft, dangerous vibrations should not occur, and significant residual deformations should not appear. The fulfillment of these requirements is ensured by the choice of a rational power circuit and cross-sectional areas of power elements, as well as the selection of materials.

Reliability and survivability requirements aircraft provide for the development and implementation of constructive measures aimed at ensuring flight safety.

Aircraft reliability represents the ability of a structure to perform its functions while maintaining performance indicators for a specified period of an inter-regulatory period, resource or other unit of measurement of operating time. Reliability characteristics are flying hours per failure, the number of failures per one flight hour, etc.

The reliability of the aircraft can be increased by selecting reliable structural elements, their duplication (redundancy).

Aircraft survivability is determined by the ability of the structure to perform its functions in the presence of damage. To meet this requirement, constructive measures are necessary, for example, the use of statically indeterminate power circuits, effective fire protection measures and, mainly, redundancy. These requirements are especially important to ensure a given level flight safety .

Operational Requirements provide for the establishment of such
structures that allow in a short time to provide technical
maintenance of aircraft with minimal material and technical costs.

The implementation of such requirements is possible by providing convenient access to the units, standardization and unification of units, units, parts of the aircraft and connectors, the use of built-in systems for automatic monitoring of the technical condition of aircraft systems and units, effective systems for troubleshooting and troubleshooting, increasing the resource and inter-regulation service life.

Maintainability Requirements predetermine the possibility of quick and cheap restoration of failed (damaged) parts of the aircraft, operational maintenance of the number of aircraft and engine fleet. The significance of these requirements is increasing due to the constant complication of aircraft and means of navigation.

There are two main types: military And civil. Structures of the first type are used to perform various strategic tasks, mainly for defense or, conversely, the destruction of military facilities. Within this family, a complex grid is formed, consisting of a complex system of subgroups. Civil liners are passenger and cargo, the main types of aircraft are discussed in more detail below.

It is worth noting that there are many groups according to various characteristics and it is impossible to single out a single most common one. So, there are the following classifications of aircraft: according to the aerodynamic configuration, according to the tail, according to the number and type of wings, and so on.

It is impossible to consider all classifications within the framework of one article. Moreover, a huge amount of literature is devoted to a detailed description of the classifications and types of aircraft. Therefore, here we will consider the most common division.

Perhaps it is worth starting with the technique used for strategic purposes, since there are more types in this category. Basically, such aircraft can be seen at parades dedicated to the Great Victory Day, in films or in museums.

Bombers

The main task that bombers must perform is to defeat ground targets from the air. For this, bombs and rockets are used. The list of the most famous bombers includes Su-24, Su-34, XB-70 Valkyrie, Boeing B-17.

The first aircraft of this type can be called "Ilya Muromets", created in 1913 by designer Igor Sikorsky. Directly under the bomber, it was converted during the First World War.

Fighters

These aircraft are used to destroy air targets. However, despite such a sonorous and rather aggressive name, fighters belong to the class of defense equipment, and as a rule, these aircraft are not used separately for the offensive. It is curious that at first the fighter pilot had to shoot at the enemy from a revolver while driving the ship, which later gave way to a machine gun. During the Second World War, fighters were actively used, for example, LaGG-3, MiG-3, Yak-1. German pilots flew Bf. 109, Bf. 110 and Fw 190.

Fighter-bombers

A universal technique that combines the qualities of the two aircraft described above. Their main advantage is that they can fire at ground targets without cover. They combine three most important features: lightness, maneuverability and sufficient weapons for a firefight. Among the most common examples are the MiG-27, Su-17, F-15E Strike Eagle, SEPECAT Jaguar.

Fighter-bomber Lockheed Martin F-35 Lightning II

Interceptors

This is a subspecies of fighters worthy of a separate class. The primary task of such aircraft is the destruction of enemy bombers. They differ from fighters by the presence of radar equipment in addition to rapid-fire guns. The well-known Soviet models include Su-9, Su-15, Yak-28, MiG-25 and others.

Stormtroopers

Aircraft from this category were designed for air support of ground forces during combat. The secondary task is the defeat of sea and ground targets. Perhaps the most famous name for ground attack aircraft designed in the Soviet Union is the Il-2. Interestingly, this particular model is the most mass-produced in history: a total of 36,183 units of this technique.

Aircraft of civil aviation

Today, air transport is one of the most popular means of transportation. In the modern world, there are so many pieces of passenger equipment that every 3 seconds, somewhere on the globe, one passenger airliner lands. Below is the most common classification of aircraft.

Passenger wide-body double-deck aircraft Airbus A380

Widebody

Such aircraft are large in size, they are designed for flights over medium and long distances (some models overcome routes up to 11,000 km long). The length of the hull can reach 70 meters, and the width of the cabin allows you to accommodate 7-10 seats in a row. Aircraft such as the Boeing 747 and A380 have two decks. Due to the high cost, aircraft from this group are at the disposal of a relatively small number of airlines.

Narrow-body

This is the largest group, liners from which are used, as a rule, for routes of short or medium length. The fuselage diameter most often does not exceed 4 meters. The most famous aircraft from this category is the Boeing 737, more precisely, 10 types of aircraft belonging to the Boeing 737 family.

Regional and local

The former include small aircraft that carry up to 100 passengers over distances not exceeding 2-3 thousand km. Notably, both turboprop and jet engines can be used. Examples of aircraft from this group include ERJ, ATR, Dash-8 and SAAB.

Local aircraft cover at a time routes no more than 1000 km long, a maximum of 20 seats are provided in the cabin. The most famous manufacturers of this equipment are Cessna and Beechcraft.

In contact with

Today, there are quite a few different aircraft, but not every one of them is called an airplane. This term refers to any aircraft that is designed to fly in the sky due to the power plant that creates thrust and wings that remain motionless at all times. It is the fixed wing that is the main characteristic of the aircraft, which distinguishes it from any other aircraft.

By itself, this term appeared back in 1857 - then the Russian pilot called the balloon so, there were no airplanes in the sense in which we use this word today. In a close to modern value, it was mentioned a few years later - in 1863. It was the article "Aeronautics", published in 1863 in the magazine "Voice". The author was the journalist Arkady Evald.

To date, there are a huge number of aircraft classifications. For example, by the number of wings, by the aerodynamic system, by the type of chassis and by speed.

In this text, we will consider one of the main typologies. Any aircraft, first of all, are divided according to their purpose. They are civilian, military and experimental. Each of these categories, in turn, is also divided into several types.

As the name implies, these are aircraft designed to carry passengers or cargo. The first flight on an aircraft of this type took place in Russia more than a hundred years ago - in 1914. The flight was made from St. Petersburg to Kyiv, and the plane was called "Ilya Muromets". There were 16 passengers on board.

Today, the most famous and frequently used airliner of our time is called the American aircraft of the Douglas DC-3 model. He first flew with passengers back in 1935. Over the past time, the aircraft has been improved, many other models, including those of Soviet aviation, were created on its basis.

Civil aircraft can be transport, training and special applications. Transport, in turn, are divided into:

Freight - for the transportation of goods;
Passenger - those planes that we fly;

There are many types of such vehicles. The easiest way to divide them is simply by manufacturer. In fact, the vast majority of aircraft in the world are produced by such companies:

Boeing

This is an American company that appeared a very long time ago, in 1916. Since then, it has been producing aircraft for civil aviation. The most popular model is the Boeing 737. It is this aircraft, released in 1968, that is most often used today. The very name "Boeing" has already become almost synonymous with the word airplane.

Airbus

This company is today the main competitor of the Boeing described above, although it was founded much later - in 1970. This European company, today its main office is located in France. Some models of this manufacturer are economical, which makes them a serious competitor to Boeing.

Military

Military aircraft are designed to conduct combat operations, that is, to protect against the enemy or vice versa, to attack. They are divided into some types, but in general, they can perform a variety of tasks - depending on the situation.

Bombers

This subspecies of military aircraft essentially has one task - the destruction of any ground objects from the air. This is done by dropping bombs or missiles on the target. To date, there are a lot of different models, among the most commonly used Su-24 and Su-34.

It was in the bomber that the first passenger plane "Ilya Muromets", which was discussed above, was converted. During the First World War, the aircraft was converted and in the future it always served as a bomber.

Fighters

Unlike bombers, such aircraft are used for air combat. The name "fighter" sounds loud and menacing, but in fact such aircraft belong to defense equipment. It is for the offensive that they are almost never used. Fighters were actively used by both sides during the Second World War - the most famous models are the MiG-3 and Yak-1.

It is interesting that in the very first models of fighters, not a machine gun was installed, as today, but a revolver, so the rate of fire was much lower.

Fighter-bombers

Naturally, the two models described above were combined to obtain a universal model that combines the functions of both types. The main advantage of this variety is the ability to bomb any ground targets without cover at all. Such aircraft are very light, maneuverable and equipped with powerful weapons. The most successful models are MiG-27, Su-17, SEPECAT Jaguar.

Interceptors

In fact, this is not a completely separate class, just a subspecies of fighters. The main difference is that interceptors are designed to destroy a specific target, namely enemy bombers. They also differ slightly in structure - such models are additionally equipped with radar equipment. famous models - Su-15, Su-9 and others.

The purpose of attack aircraft is to support ground forces from the air. They were also often used simply to destroy various objects. The most popular model is called Il-2 and this aircraft is the most mass-produced in history - almost 37 thousand units were produced.