# plane

Cessna 172 : With more than 44,000 units, the most popular aircraft type in the world
Airbus A380 : The largest mass- produced civil airliner in the history of aviation
Fighter aircraft of various generations over New York - The General Dynamics F-16 , North American P-51 , Fairchild-Republic A-10 and McDonnell Douglas F-15 (from left to right)

An airplane is an aircraft that is heavier than air and generates the dynamic lift required for its flight with non-rotating lift surfaces. The operation of aircraft at the aviation participate is by air traffic laws regulated.

Colloquially, aircraft are sometimes also called fliers , but the main meaning of the term flier is the pilot .

## definition

The International Civil Aviation Organization (ICAO) defines the term aircraft as follows:

Airplane . A power-driven heavier-than-air aircraft, deriving its lift in flight chiefly from aerodynamic reactions on surfaces which remain fixed under given conditions of flight.

- International Civil Aviation Organization

In legal usage, an aircraft is a motor-driven aircraft, heavier than (the air it displaces), which is lifted by wings that remain unchanged under constant flight conditions, commonly referred to as motor aircraft . So when a legal text refers to aircraft , it always only refers to powered aircraft, not gliders , powered gliders and microlights . The latter are a sub-class of air sports equipment in Germany .

Some authors use a broader definition according to which rotary wing aircraft are also a subgroup of aircraft. The actual aircraft are then for better definition than fixed-wing aircraft , fixed wing aircraft or fixed wing aircraft designated. However, this classification contradicts both the legal definition and general usage and can therefore be regarded as out of date.

The definition used in this article is based on the slang meaning of the term aircraft , which includes all aircraft that have a fuselage with fixed wings.

## Differentiation from other aircraft

Fairey Rotodyne : A
winged combination aircraft
Space gliders like the
space shuttle start like rockets and land like airplanes
The VTOL UAV Hummingbird flies by flapping its wings

In aircraft, the lift - when the aircraft moves forwards - is generated by deflecting the necessary air flow on the wings (with a suitable profile and angle of attack ). As a result of the deflection, an impulse directed vertically downwards is transmitted to the air. According to Newton's first law , this change in direction of the flow downwards requires a continuously acting force. According to Newton's third law ( actio and reactio ), an equal and opposite force, the lift, acts on the wing.

In addition to the rigid connection between the wing and the fuselage, there are also some types of aircraft with convertible and swivel wing planes in which the wings are flexibly fixed to the fuselage. This means that operational requirements can be met with these types that are not possible with a rigid wing. In a broader sense, the fixed wing principle is also used by aircraft with completely flexible wings, such as paragliders and motorized paragliders , as well as with dismountable wings such as hang gliders .

### Ground effect vehicles

Ground effect vehicles fly with the help of wings just above the surface of the earth and thus resemble low-flying aircraft. As a rule, however, they are not able to rise beyond the sphere of influence of the ground effect and are therefore - similar to hovercraft  - not considered aircraft.

### Rotary wing aircraft

In rotary wing aircraft ( helicopters , helicopters ) the wings are constructed in the form of a horizontal rotor . The air flow over the rotor blades results from the combination of the rotary motion of the rotor and the incoming air from its own motion and wind.

Some rotary-wing aircraft, such as the composite helicopters or combination aircraft, have, in addition to their main rotor , more or less long, fixed wings that provide additional lift.

An intermediate thing between fixed-wing aircraft and rotary wing aircraft are the convertible aircraft , which can change flight modes (flight states) in flight.

### Missiles

Unlike the aircraft, the rocket flies with a rocket engine ( recoil drive ) by ejecting the supporting mass carried along with it, independently of an air flow, even if it can have aerodynamic control surfaces for flight phases in the atmosphere . However, these are not used for buoyancy, but only for stabilization and control. A special case is the space glider , which usually starts with a launcher and lands in aerodynamic flight . It can be seen as an airplane.

### Rotor planes

A rotor aircraft has Flettner rotors as supporting elements , which use the Magnus effect . Rotor planes are rarely found even in model making and have so far had no practical significance. They must not be confused with rotary wing aircraft.

### Swing planes

In ornithopters even swing plane called the wings like birds' wings move up and down to generate lift and thrust. They are therefore sometimes also called flutter wings . In the early days of aviation in particular , attempts were made to build swing planes based on nature's example. It is not known that person-carrying aircraft of this type have flown so far, but there are functional, remote-controlled model ornithopters and micro- drones , such as. B. the DelFly of the TU Delft .

## General structure

Traditionally, an aircraft is divided into three main groups (main construction groups): airframe, engine system and equipment.

### Airframe

The airframe consists of the fuselage, the supporting structure , the tail unit , the control unit and the chassis at a land plane or to the buoyancy bodies (floats) at seaplanes . In the case of vertical take-offs and older gliders, a skid landing gear can be used instead of landing gear or floats. In many, mostly older publications, the term airframe or simply airframe is used instead of airframe .

#### Fuselage

The fuselage is the central structural element of most aircraft. The structure is attached to it, and in addition to the pilots, it also houses a large part of the operating equipment. In a passenger aircraft, the fuselage accommodates the passengers. Often the landing gear is wholly or partially on the fuselage. The engines can be integrated into the fuselage. In flying boats , the hull forms the main buoyancy body.

A distinction is made between different hull shapes. Today, round fuselage cross-sections are the rule if the machine has a pressurized cabin . Freight machines often have a rectangular fuselage cross-section in order to optimize the loading volume. Most aircraft have only one fuselage, there are also machines with double fuselages and flying wing planes .

#### Structure

Wing with
flaps extended a few degrees

In addition to one or more wings as the main component, the structure consists of all the components that provide lift.

#### Tail unit

The tail unit consists of the horizontal stabilizer with the elevators and the associated trim tabs, the vertical stabilizer with the rudder and the trim tab for it and the ailerons. In addition, the main task of the tail unit is to stabilize the given flight position and direction, and also to control all three axes of the aircraft.

Tail unit Controls effect Axis system
Tailplane Horizontal stabilizer and elevator Rotation around the transverse axis (pitching) Y axis
Vertical stabilizer Vertical fin and rudder Rotation around the vertical axis (yaw) Z axis
Surface stabilizer Ailerons and spoiler Rotation around the longitudinal axis (rolling) X axis

#### Control unit

In a fixed wing aircraft, the control unit or control system consists of the control stick or the control column with control horn or handwheel and the rudder pedals with which the control commands are given. Linkages, cables, hydraulics, electrical ( fly-by-wire ) or optical ( fly-by-light ) signals can be used to transmit the control forces or signals . The control column is replaced by the sidestick on some modern aircraft .

#### landing gear

The landing gear enables an aircraft to move on the ground, to achieve the required take-off speed, to absorb the impacts of the landing and shocks e.g. B. to dampen by bumps. Landing gears are divided into a rigid and semi-rigid landing gear, which also maintains its position unchanged during the flight, whereby the semi-rigid landing gear is partially retracted (e.g. only the nose landing gear), and a retractable landing gear, which is used before and after take-off or landing can be drawn in and, if necessary, covered by landing gear flaps. Retractable landing gears are essential for aircraft with high top speeds. The nose wheel landing gear is used as the landing gear, in which a small wheel is attached under the front of the aircraft and the main landing gear is behind the aircraft's center of gravity. This gives the pilot a good view while taxiing on the ground. The formerly widespread rear or tail landing gear with a small wheel or a grinding spur at the rear is rarely used today. A special feature is the tandem undercarriage, in which the undercarriage parts that carry the main load are the same size at the front and rear of the fuselage and the aircraft is stabilized by support wheels on the wing.

### Engine

Turbofan engine of a Boeing 747

The power plant of an aircraft comprises one or more motors (generally of the same type) with accessories. The most common designs are: reciprocating piston engine ( aircraft engine ) with propeller , gas turbine (shaft power engine ) with propeller ( turbo-prop ) and the turbine jet engine , mostly in turbofan design. Ramjet engines , rocket engines and electric motors are rare / experimental .

The accessories include the fuel system and lines, if necessary a lubrication system , the engine cooling system , engine support and engine cowling.

Outside of combat flying, the jet engines are no longer integrated in the wings or fuselage for maintenance reasons, the Nimrod MRA4 is an exception .

Kerosene , AvGas , MoGas or ethanol are usually used as fuel .

### Operating equipment

Operating equipment: cockpit of a Dornier Do 228

The operating equipment of an aircraft includes all on-board components of an aircraft that do not belong to the airframe and engine and which are necessary for the safe execution of a flight. It consists of the components for monitoring the attitude , flight and engine status, for navigation , for communication , supply systems, warning systems, safety equipment and, if necessary, special equipment. The electronic part of the operational equipment is also called avionics .

Many specialist authors now count the control unit or the control unit no longer part of the airframe, but rather part of the operating equipment, since the control of modern aircraft is significantly influenced by the sensors of the operating equipment and by on-board computers.

## Construction methods

Materials for aircraft should have the greatest possible strength (see also specific strength ) against static and dynamic loads , so that the weight of the aircraft can be kept as low as possible. In principle, steels , light metal alloys , wood , fabrics and plastics are particularly suitable for aircraft construction. While wood up to medium sizes has been used sensibly, all-metal and composite construction is generally preferred in aircraft construction today, in which different materials are combined in such a way that their respective advantages complement each other optimally.

Structures on aircraft can be implemented using different construction methods. A distinction can be made between four construction methods, wood construction, mixed construction, metal construction and FRP construction .

### Wooden construction

Inside view of the wooden fuselage of a Fisher FP-202

In the wooden construction , a frame made of wooden longitudinal straps and frames is glued for the hull , which is then planked with thin plywood. The wing consists of one or two spars to which the so-called ribs are glued at right angles at the front and back . The ribs give the wing the right shape. In front of the spar, the wing is planked with thin plywood, this planking is called a torsion nose . It prevents the wing from twisting parallel to the spar during flight. Behind the spar, the wing is covered with a fabric made of cotton or special plastic. This material is glued to the spar or the torsion nose and to the trailing edge that connects the ribs on the wing's trailing edge and coated with tensioning varnish. Tensioning varnish contracts as it dries and thus ensures that the covering is taut. In the case of powered aircraft, the fabric must also be sewn onto the ribs. More modern upholstery fabrics made of plastic contract when heated, they are ironed to stretch. In powered aircraft, aluminum powder is mixed into the upper layers of tensioning lacquer as UV protection. Examples of such aircraft are e.g. B. the Schleicher Ka 2 or the Messerschmitt M17 . The pure wood construction is now out of date.

Metal construction:
Shell construction of a Bushcaddy R-80

### Metal construction

The metal construction is the most common type of construction for powered aircraft. The fuselage consists of a welded or riveted metal frame, which is planked with sheet metal on the outside. The wings consist of one, in the case of large aircraft, several, spars to which the ribs are riveted or screwed. As with the fuselage, the planking consists of thin sheet metal. One of the most famous motorized aircraft made of metal is the Cessna 172 , but there are also gliders made of metal, such as the LET L-13 Blaník .

### Mixed construction

The fuselage of a Piper PA-18 (mixed construction: metal frame and covering) here without covering during a major overhaul

The mixed construction is a mixture of wood and metal construction. Usually the fuselage consists of a welded metal frame, which is covered with fabric, while the wings are built as in the wooden construction. However, there are also airplanes whose wings also consist of a covered metal frame. The basic structure of spars and ribs differs from the wooden construction only in the materials used. The Schleicher K 8 is an aircraft with a fuselage made of a metal frame and wooden wings, while the wings of the Piper PA-18 are made of an aluminum frame.

An aileron of a Schleicher ASK 21. The FRP is sanded, the individual fiberglass layers are clearly visible.

### Plastic construction

For some years now, metal construction has been increasingly being replaced by fiber-composite plastic construction (FRP construction for short). The aircraft consists of mats, mostly fabric made of glass, aramid or carbon fibers, which are placed in molds, soaked with synthetic resin and then cured by heating. In addition, a support material, either rigid foam or a honeycomb structure, is glued into the areas of the aircraft that have to absorb a lot of energy. Here, too, frames in the fuselage and spars in the wings are not dispensed with. The FRP construction was first used in gliding, the first aircraft of this construction was the FS 24, the prototype was built from 1953 to 1957 by Akaflieg Stuttgart . In the meantime, however, manufacturers of powered aircraft are also switching to FRP construction. B. Diamond Aircraft or Cirrus Design Corporation . Examples of the FRP construction are the Schempp-Hirth Ventus or the Diamond DA40 . Particularly in large aircraft construction, combinations of metal and FRP construction are currently being produced. A popular example is the Airbus A380 .

## Maintenance and service life

### maintenance

Aircraft are subject to mandatory maintenance requirements by certified companies throughout their life. These are divided into A-, B-, C- and D-Check, the latter takes place after about six to ten years or several 10,000 flight hours. The entire aircraft is being overhauled. The maintenance intervals for the turbines are 20,000 flight hours.

### lifespan

In contrast to certain individual components such as landing gear , aircraft are generally not subject to a maximum operating time. When designing their aircraft, commercial aircraft manufacturers only set one target value for the service life, at Boeing called the Minimum Design Service Objective , at Airbus Design Service Goal (DSG). These target values ​​are based on typical use within 20 years. Most types are designed for about 50,000-60,000 flight hours; the number of possible flights varies between 20,000 for long-haul aircraft, e.g. B. Boeing 747 , and 75,000 for short-haul aircraft, e.g. B. Boeing 737 . These minimum targets are exceeded in large numbers, particularly with regard to age and flight hours. Even before the first machine reaches the limit of the DSG, Airbus offers an extended limit Enhanced Service Goal (ESG) in connection with certain maintenance requirements. Since 1988, the incident on Aloha Airlines flight 243 has brought the issue of widespread fatigue damage (WFD) in older aircraft to the attention of authorities and manufacturers. For aircraft with a maximum take-off weight of 75,000 pounds (34 t), the Federal Aviation Administration has required manufacturers to specify Limits of Validity (LOV ) from 2013–2017 (depending on the age of the aircraft type) since 2011 , beyond which the aircraft may no longer be operated. These upper limits are well above the minimum target of 30,000–110,000 flights or 65,000–160,000 flight hours. Boeing estimates that when the oldest aircraft come into effect in July 2013, only 25 Boeing machines worldwide will be above the new LOV. Military aircraft are designed for a service life of approx. 15 years, but only for 5,000–8,000 flight hours.

A traffic machine covers an average of 5 km per flight on the tarmac. This results in a mileage on the ground of more than 250,000 km within the service life.

## Basics: buoyancy and propulsion

### boost

Forces on the plane

The size of the dynamic lift force on a wing (with its given profile ) is determined by the size of the angle of attack (the angle between the inflowing air and the wing plane ), the profile shape, the wing size , the density of the air and its flow speed. By increasing the angle of attack at constant airspeed, the lift increases proportionally; this does not apply to the peculiarity of supersonic flight . In lifting body aircraft, the fuselage is aerodynamically shaped in such a way that it provides a large proportion of the lift.

In straight flight the lift force is equal to the weight ( equilibrium ); in flight maneuvers such as take-off and climb it is greater, and in descent it is less than the weight force.

### Relationship between lift, propulsion and air resistance

In order to move forward, the aircraft must generate propulsion in order to overcome the drag that inhibits free forward movement. The air resistance of an aircraft is dependent

• form drag , also called parasitic drag , caused by the friction of the air on the body of the aircraft,
• from buoyancy. The “induced” part of the air resistance that is dependent on lift is called the induced drag .${\ displaystyle F_ {a}}$

While the parasitic drag power increases with increasing flight speed in the third power of the speed, the induced drag power decreases inversely proportionally. The resulting total resistance leads to a loss of energy during the flight, which must be compensated for by adding energy (fuel, solar or wind energy) in order to continue the flight. If the energy supplied is greater than the loss due to the total resistance, the aircraft is accelerated. This acceleration can also be converted into a gain in altitude ( conservation of energy ).

Both a favorable drag coefficient ( value) and the ratio of drag coefficient to lift coefficient , the glide ratio, are decisive for the aerodynamic quality of an aircraft . ${\ displaystyle c_ {w}}$${\ displaystyle c_ {w}}$${\ displaystyle c_ {a}}$ ${\ displaystyle E}$

The relationship between the drag coefficient and the lift coefficient of a certain wing profile and thus its aerodynamic characteristics is called the profile polar, shown in the Otto Lilienthal polar diagram .

This results in the buoyancy formula

${\ displaystyle F_ {a} = c_ {a} \ cdot q \ cdot A}$

as well as the resistance formula

${\ displaystyle F_ {w} = c_ {w} \ cdot q \ cdot A,}$

where and stands for the coefficients of lift and drag, for dynamic pressure (depending on speed and air density) and for the reference area . ${\ displaystyle c_ {a}}$${\ displaystyle c_ {w}}$${\ displaystyle q}$${\ displaystyle A}$

### Airspeed and flight envelope

A distinction can be made between the following expressions for speeds:

• Indicated air speed (IAS)
• Calibrated air speed (CAS) is the IAS corrected for the instrument error.
• Equivalence speed (EAS) is the CAS corrected for compressibility.
• True air speed (TAS) is the EAS corrected for the air density at a higher altitude.
• Speed (Engl. Above ground groundspeed , GS) is corrected by the wind TAS.
• Mach number (engl. Mach number , MN), a EAS expressed by a multiple of the speed of sound.

The pilot receives the speed in relation to the surrounding air via his airspeed indicator . This is determined from the static and dynamic pressure on the pitot tube of the airspeed indicator. This indicated air speed (IAS) is dependent on the air density and thus the flight altitude. The IAS is decisive for dynamic lift . It is therefore of the greatest importance to the pilots. In modern cockpits , the IAS is mathematically corrected for the instrument error and displayed as a CAS.

The possible speed range of an aircraft depending on the flight altitude is represented by the flight envelope . The lower limit is represented by the pulling speed, the upper limit by the reaching of the strength limits. In aircraft, which due to the high power of their engine can reach the speed of sound, but which are not designed for supersonic flights, it is a certain distance below the speed of sound.

How fast an aircraft flies in relation to the speed of sound is represented by the Mach number . Named after the Austrian physicist and philosopher Ernst Mach , the Mach number 1 is equated to the speed of sound. Modern commercial aircraft with jet engines are i. A. Optimized for speeds (IAS) from Mach 0.74 to 0.90.

In order for the wing to generate sufficient lift, at least the minimum speed is required. It is also called stall speed named because when they fall below a stall (Engl. Stall occurs) and the resistance rises sharply, while the lift breaks down. The stall speed will decrease when high flotation devices (such as landing flaps ) are deployed.

With rotary wing aircraft, the flight speed is limited by the aerodynamics of the rotor blades : On the one hand, the blade tips can reach the supersonic range, on the other hand, the flow can stall when the aircraft is reversing.

The drive power to be installed based on the mass of the rotary wing aircraft also increases disproportionately to the possible maximum speed.

Aircraft take off and land advantageously against the wind. As a result, the displayed speed contributing to the lift is greater than the speed over the ground, with the result that much shorter take-off and landing distances are required than with a tailwind.

### Types of propulsion

There are various options for generating the propulsion, depending on whether and which means are to be used with which force generation and transmission principle:

Without self-propulsion
With gliders , hang-gliders and paragliders , propulsion is guaranteed even without self-propulsion, as the existing height can be converted into speed with little loss. The gain in height itself is achieved by towing with winches ,
tow planes or updrafts (e.g. thermals or upwinds on slopes and waves), or by increasing the starting position.

Propeller in connection with muscle power

In 1934, the Zaschka muscular power aircraft was able to achieve hovering flights of 20 meters in length in Berlin-Tempelhof without external help.
The Gossamer Albatross is an airplane powered by muscle power. With him in 1979 the English Channel was crossed.

Muscle- powered aircraft (HPA) represent an extreme form of propeller drive : A muscle-powered aircraft is only propelled with the help of the pilot's muscle power, utilizing the gliding properties of the aircraft construction, which understandably must be extremely light. This is especially true for muscle power helicopters

Propeller in connection with an electric motor
A propeller can also be driven by an electric motor. This type of propulsion is mainly used in solar and model airplanes , now also in microlight aircraft .

Propellers in connection with piston engines
Propellers in connection with piston engines were the common type of drive until the development of the gas turbine. The practical power limit for aircraft engines of this type was 4,000 PS (2,940 kW) and the achievable speed was 750 km / h. Today this type of propulsion is common for smaller one to two-engine aircraft. Due to the special requirements for the safety of the engines, special aircraft engines are used.

Turboprop
Propeller turbine engines - turboprop for short - are used for short and regional commercial aircraft, military transport aircraft, maritime patrol aircraft and single or twin-engine business aircraft in the subsonic range. Further developments for future use in commercial aircraft and military transport aircraft are "Unducted Propfan", also known as "Unducted Fan" (UDF) and "Shrouded Propfan" (e.g. MTU CRISP).

Turbine
jet engine Turbine jet engines are used for modern, high-speed aircraft up to near the speed of sound (up to the transsonic speed range or the
transonic speed range) or also for speeds in the transsonic and supersonic range. For flights in the range of supersonic speeds , turbojet engines often have an afterburning system to increase performance .

Ramjets
Ramjets reach hypersonic speeds and have only a few moving parts. However, they work i. A. only at high speeds and must first be accelerated to them in some other way. A combination of turbojet engine with afterburning and ramjet engine is called a turbojet engine or turbo-amjet.

Deflagration jet engine
Historically, the deflagration jet engine was the predecessor of the rocket engine, at that time for cruise missiles . It is easy to build because of fewer moving parts and simple functionality; extremely high wear only enables operating times of (maximum) a few hours. Because of the very loud operating noise, detonation jet engines are banned in many countries (including the Federal Republic of Germany ).

Rocket
engines Rocket engines have so far only been used in experimental aircraft.

Booster
In order to increase the propulsion and especially the lift when starting STOL aircraft, boosters in the form of jet engines (example: variants of the Fairchild C-123 ) or solid or steam rockets (see also boosters (rocket propulsion) ) were sometimes used .

Convertible plane

Convertible aircraft, also known as transformation aircraft or transformation helicopters, use the configuration of a helicopter for vertical takeoff. When transitioning to forward flight, they are reconfigured to be a fixed-wing aircraft. In this way they combine the advantages of rotary wing and fixed wing aircraft. The conversion usually takes place by tilting the rotor, which then works as a traction engine - called tilt rotor or tiltrotor (e.g. Bell-Boeing V-22 ). The convertible aircraft also include tilt-wing, tilt -rotor, retractable-rotor and stop-rotor aircraft . Most non-jet powered vertical takeoff aircraft ( VTOL aircraft) are convertible aircraft.

## Flight control

The flight control, engl. Flight Control System (FCS), comprises the entire system for controlling aircraft around all three spatial axes. In addition to the control surfaces and the control elements in the cockpit, this also includes the transmission of control inputs (see also fly-by-wire ).

### axes

Axes of an airplane

To describe the control, axes are named: transverse axis ( English pitch ), longitudinal axis ( English roll ), and vertical axis ( English yaw ). In a 3-axis-controlled aircraft, one or more control surfaces are assigned to each axis. A 2-axis control dispenses with z. B. on ailerons or rudder, the missing component is replaced by the inherent stability . See also: Roll-Pitch-Yaw Angle

### Control surfaces and control nozzles

The control may be performed by various components: the rudder and flaps jet flap called slot dies, by adjusting the jet engines ( thrust vector control : the exhaust plume can be moved in different directions), by twisting of the wing and tail, or by shifting weight. In the case of vertical take-offs, the tilting or swiveling of rotors or jet engines are additional control options, particularly in hovering and transition flight.

Rudders as control surfaces

The control of an aircraft is shown using the example of control via rudders:

• The ailerons at the rear end of the wings control - always at the same time and in opposite directions - the bank angle of the aircraft, i.e. the rotation around the longitudinal axis, the roll .
• The elevators at the rear of the aircraft regulate pitch , also known as pitching or tilting , by changing the angle of attack.
• The rudder - in conventional fixed-wing aircraft at the rear end of the aircraft - is used for side steering, also known as turning or yawing .
• Trim tabs on the elevator are used to trim the height. Larger aircraft also have aileron and rudder trim tabs.
• Spoilers ( English spoiler ) serve to limit the speed during descent and reducing the buoyancy.

The aircraft can turn around one or more of these axes simultaneously.

The elevator is usually attached to the rear of the aircraft fuselage, as is the rudder, this combination is known as the tail unit. In contrast to this, the height control can also be placed at the front (canard).

Elevator and rudder can also be combined as with the V-tail .

The function of the ailerons can be replaced by opposing deflection of the elevators.

All types of trim tabs serve to stabilize the aircraft attitude and make flight control easier for the pilot. In modern aircraft, the autopilot takes control of the trim tabs.

The high-lift aids are used for take-off, climbing and landing . At the trailing edge of the wing are the trailing edge lift aids or flaps, which, in contrast to the oars, are always used synchronously on both wings. Larger aircraft and STOL aircraft usually also have nose lift aids in the form of slats , Kruger flaps or nose flaps (tilting noses), which extend on the front wing edge analogous to the flaps on the rear wing edge. The flaps can be used to change the curvature of the airfoil in such a way that the tear-off speed is reduced and lift is maintained even during a slow landing approach or when climbing.

To limit the speed in descent, so-called brake / spoilers, called “spoilers”, are used on the wings. When extended, they reduce the lift on the wings ( flow separation ). A steeper landing approach is possible due to the reduced lift. Spoilers are also used to support the ailerons - in certain flight areas also as a replacement for - ailerons. After landing, the spoilers are fully extended so that no (positive) lift can act. This is usually done by an automatic mechanism that is initiated, among other things, by the compression of the main landing gear during landing.

There are also control surfaces with multiple functions:

In addition to the conventional arrangement of the control surfaces, there are also special forms, as indicated above:

### Controls

Control elements are those levers and pedals that can be operated by the pilot in the cockpit and are used to control the aircraft.

Joystick, or control stick sidestick
joystick , control horn or sidestick serve to control the transverse position and the longitudinal inclination and control the ailerons and the elevator.

The control stick of an aircraft is used to control bank and pitch at the same time. It is located in front of the pilot's lower abdomen and is usually held with one hand.

The control horn is another unit used to control aircraft around the longitudinal and transverse axes. It is located in the cockpit in front of the pilot and has handles for both hands. The forces that act on the aircraft during flight are transferred to the control unit in the form of resistance and deflection.

A sidestick is a control stick that is not positioned centrally in front of the pilot, but on the side and can only be operated with one hand.

Rudder pedals
The
rudder pedals operate the rudder and usually also the brakes on the ground . On gliders, the wheel brake (if available) is usually operated by pulling the airbrake lever.

Trim
serve to permanently trim

• a trim wheel or a trim lever to compensate for head or tail heaviness (height trimming),
• a trimming unit to compensate for lateral force differences, e.g. B. in multi-engine aircraft to compensate for an engine failure (side trim).

### Signal transmission

The control signals can be transmitted

### Instruments for recognizing the situation in space

The pilot recognizes his position in space either by observing the details of the area flown over and the horizon or by means of display instruments ( flight navigation ). When visibility is poor, the artificial horizon is used to display the flight position in relation to the pitch axis, i.e. the angle of attack of the aircraft fuselage, and in relation to the roll axis, the so-called bank position. The direction in which the aircraft is flying is shown by the magnetic compass and the course top . Magnetic compass and course gyro complement each other, since the magnetic compass tends to make errors in turning and acceleration when descending, climbing and turning, but the course gyro does not. However, the heading gyro does not have its own "north-looking" property and must be calibrated with the magnetic compass at least before take-off (in practice, at regular intervals when flying straight ahead). The turn indicator is used to indicate the direction of rotation and to measure the speed of rotation of the aircraft around the vertical axis (rate of turn). It usually contains a spherical vial that shows how coordinated a curve is being flown.

At least two instruments are important for altitude control: the absolute altitude in relation to sea ​​level is displayed via the barometric altimeter , the relative change in altitude, the so-called rate of climb or descent, expressed as altitude difference per unit of time, is signaled to the pilot via the variometer . In addition, when approaching larger aircraft, the absolute height above ground is displayed using the radar altimeter .

## Further classifications

In addition to the obvious classification according to the construction or the type of drive, other classifications have become established.

### Classification according to intended use

#### Civil aircraft

Civil aircraft are used for civil aviation , including general aviation and scheduled and charter traffic by airlines . Civil aircraft are mainly classified according to the following scheme:

The first aircraft were experimental aircraft . Experimental aircraft, also called test aircraft, are used to research techniques or to test research findings in the field of aviation.

Very early in the history of the aircraft also created sport aviation . A sport aircraft is a light aircraft for the exercise of a sporting activity, either for recreation or for a sporting competition.

Even before the First World War, the passenger aircraft was tested and built. Passenger aircraft are used for civil passenger transport and are also known as commercial aircraft . Smaller passenger aircraft are also known as feeder aircraft . Small passenger aircraft specially designed for business travelers are the business aircraft for which the engl. Expression Bizjet is used.

A cargo aircraft is an aircraft used to transport (commercial) cargo. Aircraft seats are therefore only built in for the crew; today they usually contain a transport system for pallets and aircraft containers.

A sub-category of cargo aircraft is the mail plane . Early mail planes could also be used to transport individuals.

Special aircraft for the field of agriculture and forestry, the fertilizer , soil-improving substances and plant protection products can carry in containers and can spread via spray nozzles, spreading plate or similar devices. They are commonly referred to as agricultural aircraft .

Fire-fighting planes, also known as "water bombers", are planes that can carry water and extinguishing additives in built-in or built-on tanks and throw them off via damaging fires .

There are various different categories under the term rescue aircraft (officially called "air rescue equipment ") such as rescue helicopters , intensive care transport helicopters , emergency doctor helicopters or aircraft to bring patients back from abroad. The umbrella term Search and Rescue (SAR) includes aircraft that are used to search for and rescue accident victims.

There are numerous special designs such as B. Research aircraft with special equipment (special radar , photo cameras, other sensors).

#### Military aircraft

Military aircraft are aircraft that are subject to military use. However, it is not always easy to draw the line cleanly. Many aircraft have both military and civil uses. Military aircraft are differentiated according to the following uses:

A fighter is a military aircraft primarily used to combat other aircraft. Today one speaks more of the fighter aircraft , as the aircraft cannot be assigned to any specific task in this category. They are used for aerial combat , military reconnaissance , tactical ground combat and / or other tasks.

A bomber is a military aircraft that is used to attack ground targets with aerial bombs, air-to-surface missiles, and cruise missiles.

A liaison aircraft is a small military aircraft that is typically used to transport commanders . It can also be used for battlefield reconnaissance (nowadays only for troop exercises), serve as a smaller ambulance aircraft or be used for messenger services. Today light helicopters are mostly used as liaison aircraft.

In- flight refueling refers to the transfer of fuel from one aircraft to another in flight. The aircraft that provides the fuel is usually a tanker aircraft specially developed for this task.

A reconnaissance aircraft is a military aircraft that is designed, converted, or equipped for the task of gathering information for military reconnaissance. Sometimes reconnaissance planes are also referred to as spy planes.

An attack aircraft , also known as ground attack aircraft is a military aircraft that is intended specifically for the fight against ground targets. This type represents its own type of aircraft, which is supposed to fulfill very specific tactical tasks. Since the attacks take place at low to medium altitudes and strong defensive fire is to be expected, special protective measures are taken, such as armoring the cabin and engines against ground fire. Transport aircraft that are equipped with laterally aligned machine weapons or even tubular artillery are called gunships . Rotary wing aircraft in the role of ground attack aircraft are known as attack helicopters .

A trainer is an aircraft that is used to train pilots.

Transport aircraft are special cargo aircraft that are developed for military cargo transport. They have to be robust, reliable, variably suitable for the transport of people, materials or freight and be able to be loaded and unloaded quickly. Can be transported, also in combination, for example relief supplies, parachutists, vehicles, tanks, troops or equipment.

In practice, the classification cannot always be strictly separated between civil and military, because some purposes can be given regardless of the use. For example, cargo or transport aircraft, depending on the cargo, medical aircraft depending on the doctor / patient and trainer, depending on the teacher / student, can be used in both civil and military areas.

### Classification according to the structure of the aircraft

Aircraft that have rigid wings are often categorized according to the number and position of the wings relative to the fuselage.

A monoplane is an aircraft with a single wing or a pair of wings. Monoplane, in turn, are divided into

• Low- wing aircraft , where the underside of the wing is flush with the underside of the fuselage;
• Mid- decker , in which the wing is arranged in the middle of the fuselage sides;
• Shoulder- wing planes in which the wings are arranged on or in the top of the fuselage;
• High- wing aircraft in which the wing is strutted over the top of the fuselage.

Biplane is the name of an aircraft that has two vertically staggered wings. A special form of the double decker is the "one and a half decker". Around the time of the First World War there were also triplane .

Double- fuselage aircraft have two fuselages; they are, in a sense, the catamarans of aircraft. Each fuselage usually has its own cockpit. Not to be confused with this are airplanes with a double tail girder, which however only have one fuselage, which is mostly designed as a fuselage nacelle.

Asymmetrical aircraft are a very rare type of aircraft, the most famous example being the Blohm & Voss BV 141 from 1938. Here the aircraft cockpit is on the wing, while the propeller and motor occupy the fuselage alone. The wings are asymmetrical.

An aircraft is referred to as a canard or duck aircraft in which the horizontal stabilizer is not conventionally mounted at the rear end of the aircraft, but in front of the wing on the aircraft nose; the flight image is reminiscent of a flying duck. If, in extreme cases, both wings are approximately the same size, this design is also referred to as a tandem wing .

A flying wing is an aircraft without a separate elevator, where there is no differentiation between wings and fuselage. If the fuselage itself forms the lifting body and it no longer has the typical dimensions of a wing, it is referred to as a lifting body . The union of these two concepts is called a blended wing body .

A seaplane is an aircraft that is designed to take off and land on bodies of water. It usually has a light, boat-like float under each of the two wings. When flying boats , the entire body is buoyant. Seaplanes and flying boats can only take off or land in the water. If these aircraft are equipped with (mostly retractable) landing gear, with which they can also take off and land on land, they are called amphibious aircraft .

### Classification according to take-off and landing characteristics

Fixed wing aircraft and some types of rotary wing aircraft require a more or less prepared runway of a certain length. The requirements range from a level lawn without obstacles to an asphalt or concrete runway.

Airplanes that get by with particularly short runways are classified as short take-off aircraft or STOL aircraft.

Aircraft that can take off and land vertically are vertical take-off aircraft or VTOL aircraft. You don't need a runway at all, just a solid base of sufficient size that can support your weight and on which the downwash generated by the VTOL aircraft does not cause too much damage, e.g. . B. a helipad .

VTOL aircraft that take off and land vertically on the ground are tail starters .

### Unmanned aircraft

Bundeswehr reconnaissance drone Luna

In the civil sector, unmanned aircraft are mostly used as model aircraft and are controlled via radio remote controls , rarely via program controls .

Unmanned aircraft in military or government use are called drones . The spectrum ranges from model airplanes to represent targets for anti-aircraft guns to unmanned reconnaissance aircraft and unmanned armed combat aircraft (combat drones). In the state sector, drones are used by the police and customs to search for and prosecute perpetrators, often with video and thermal imaging cameras, for which manned police helicopters were previously used. The control also takes place via radio remote control or program control.

While drones are usually reusable, unmanned aircraft with built-in warheads are known as cruise missiles .

## history

### The aviation pioneers

Between 1810 and 1811, Albrecht Ludwig Berblinger , the famous tailor from Ulm , constructed his first airborne glider, but demonstrated it to the public over the Danube under unfavorable wind conditions and fell into the river under the mockery of the spectators.

The English scholar Sir George Cayley (1773 to 1857) was the first to study and describe in a fundamental way the problems of aerodynamic flight. He broke away from swing flight and published 1809 to 1810 a proposal for an aircraft "with an employed surface and a propulsion mechanism". He was the first to describe the principle of the modern fixed-wing aircraft. In 1849 he built a manned triplane that flew a short distance.

The Russian Alexander Moshaiski built an airplane with a steam engine drive , with which he made several flight attempts between 1882 and 1886. The aircraft was able to take off from the ground, but subsequently lost speed and sagged. Its improved version, which was equipped with more power, would be airworthy according to the conclusion of the Russian aeronautical research institute ZAGI (tested in 1982). However, due to the death of the designer, the flight did not take place.

#### Otto Lilienthal and Clement Ader

Glider models like those flew by Otto Lilienthal

The aviation pioneer Otto Lilienthal (1848–1896) developed gliding planes after extensive theoretical and practical preparatory work and carried out successful gliding flights based on the principle of “heavier than air”. He has sailed well over 1,000 times. The maximum flight distances achieved were 250 meters. He tested the aerodynamic shape of his wings on his "rotary machine", which was functionally a forerunner of modern wind tunnels .

Clement Ader carried out the first (uncontrolled) motorized flight in history with his Eole. The Eole was a cantilever flying wing monoplane that was powered by a four-cylinder steam engine that acted on a four-bladed propeller. The Eole took off on its only flight on October 9, 1890, flew about 50 m, crashed and was destroyed in the process.

The German-American aviation pioneer Gustav Weißkopf is said to have covered one of the first controlled motorized flights in 1901 over a distance of half a mile. There was only testimony about this, but no photographic evidence.

Karl Jatho attributed to himself, in handwritten notes assigned to him, "air jumps" with his motorized Jatho kite from August 18, 1903, which initially ranged from approx. 18 m, later up to approx. 60 m. The timing of these notes and the timing of their publication are unclear; Just as unclear is the status of witness statements about these leaps in the air, which are said to have been made in August 1933, i.e. 30 years later. Attempts to fly the Jatho kite documented for 1907 failed.

#### Wright Brothers

Wright Flyer

The outstanding achievement of the Wright brothers was to have been the first to build an aircraft with which a successful, continuous, controlled powered flight was possible, and to have carried out this powered flight on December 17, 1903. In addition, they documented their flights in great detail and within a short period of time proved beyond doubt the suitability of their aircraft in other flights. Of outstanding importance is that Orville Wright was able to fly a full circle with the Wright Flyer as early as 1904. On the edge it should be noted that the Wright Flyer was the type after a " canard ", so the height control was in front of the main structure.

Samuel Pierpont Langley , a secretary at the Smithsonian Institute , tried a few weeks before the Wright flight to get his "Aerodrome" to fly. Although his attempt failed, the Smithsonian Institute claimed for some time that the Aerodrome was the first "airworthy machine". The Wright Flyer was donated to the Smithsonian Institute on the condition that the Institute could not recognize any previous motorized flight. This condition was formulated by the founders in order to prevent the institute's earlier presentation that Langley had carried out the first successful powered flight with the Aerodrome. This requirement repeatedly led to the assumption that there had been successful attempts at powered flight before the Wright Flyers, but that recognition had been suppressed in connection with the foundation requirement.

The first motorized aircraft were mostly biplanes. As an experiment, more than three wings were arranged one above the other. Such a multi-decker construction came from the Englishman Horatio Frederick Phillips . With the fifty-decker “Horatio Phillips No. 2 ”he made his first powered flight in England in the summer of 1907.

#### First crossing of the English Channel

In 1909, Europe set further practical milestones in the history of the airplane. On July 25, 1909, Louis Blériot was the first to cross the English Channel in an airplane with his Blériot XI monoplane . His flight from Calais to Dover took 37 minutes at an average altitude of 100 meters. Blériot was thus able to receive the cash prize offered by the English newspaper Daily Mail for the first canal crossing. With the Blériot XI, its designer became the “father of modern monoplane”. The success of the machine made him the first commercial aircraft manufacturer .

From August 22 to 29, 1909, the “Grande Semaine d'Aviation de la Champagne” was an air show near Reims that set several records: Henri Farman flew a distance of 180 kilometers in three hours. Blériot flew the highest airspeed over the 10-kilometer route with 76.95 km / h. Hubert Latham reached the highest altitude at 155 m on an "Antoinette" from aircraft designer Levasseur .

In 1910 the French engineer Henri Fabre made his first seaplane flight with the Canard Hydravion he had designed .

#### Monocoque

Formerly Aéroplane A.Deperdussin

In 1912, Louis Béchereau invented the monocoque construction method for aircraft. The fuselages of other aircraft consisted of a frame covered with painted fabric. The Deperdussin monocoque racing aircraft designed by Béchereau, however, had a streamlined fuselage made of a wooden shell without an internal frame . The "DEP" control was also new, with a steering wheel for the roll movement on the joystick for the pitching movement, a principle that is still widely used today. The aircraft was powered by a special aircraft engine, the Gnôme rotary engine . The Deperdussin Monocoques were the fastest aircraft of their time.

A major technical breakthrough came shortly before the First World War with the Russian designer and pilot Igor Ivanovich Sikorski , who later became known in the USA as a manufacturer of flying boats and a designer of helicopters. From 1913 to 1914 he proved with the first "large aircraft" he designed, the twin-engine Grand Baltiski , the four-engine Russki Vitjas and its successor, the four-engine Ilya Muromets , that such large aircraft can fly safely and stably, even with one or two engines are turned off or fail.

### The First World War

During the First World War , the military recognized the value of aerial reconnaissance. At the same time, they wanted to prevent the enemy from investigating. The airplane became a weapon, and the foundations of air warfare with propeller-driven airplanes were laid. The aircraft with pusher propellers, which were still widespread at the beginning of the war, were replaced by the more agile and faster machines with pull propellers. This was due to the fact that the synchronization of the on- board machine guns with the propeller was developed using an interrupter gear, so that the rigid armament could shoot through its own propeller circle. In this way, the pilot could target the enemy with the plane, which made the use of machine guns in air combat much more successful. Grenades , flechettes and then the first special high-explosive and incendiary bombs were dropped from the aircraft . First the soldiers in the enemy lines and later factories and cities were to be hit.

During the First World War, an aircraft industry was created from the ground, the first airfields were built and the technology of aviation radio was developed. The use of new metals (aluminum) made aircraft engines ever more powerful.

In 1915, Hugo Junkers tested the world's first all-metal aircraft , the Junkers J 1 . In 1919 Hugo Junkers also built the world's first all-metal airliner , the Junkers F 13 , whose design principles set the trend for the following aircraft generations.

### Interwar period

During the First World War, aircraft production had been greatly boosted. After this war, aircraft manufacturers had to struggle to survive as not so many military aircraft were needed. In Europe in particular, many of the former aircraft manufacturers went bankrupt if they did not succeed in converting their production to civilian goods. In the US, fighter jets could be bought at bargain prices. Former fighter pilots had to look for new jobs.

Commercial civil aviation

Many new civil services and airlines emerged in both the US and Europe , such as B. the Luft Hansa 1926. The most famous passenger aircraft of this time were the Junkers F 13 , the Junkers G 38 , the Dornier Wal , the Handley Page HP42 and the Junkers Ju 52 / 3m .

Long haul flights

Curtiss NC-4

The great challenge after the war was long-haul flights, especially crossing the Atlantic. This task cost several lives until one of three Curtiss flying boats of the US Navy launched in Newfoundland , the Curtiss NC-4 , landed in Lisbon on May 27, 1919 after 11 days .

Alcock and Brown's Vickers Vimy after crash landing at Clifden
Fieseler "Storch" (from 1936)

In the period from June 14th to 15th, 1919, British pilots Captain John Alcock and Lieutenant Arthur Whitten Brown made the first non-stop flight across the Atlantic from west to east. Your aircraft was a twin-engine modified Vickers Vimy IV bomber with an open cockpit.

Between May 20 and 21, 1927, Charles Lindbergh made the first non-stop solo flight from New York to Paris across the Atlantic with his “Ryan NYP” Spirit of St. Louis aircraft . He wins the Orteig Prize, which has been awarded since 1919 . This overflight alone gave the US aircraft industry and US airlines a significant boost. A trip by Lindbergh financed by Daniel Guggenheim to all US states led to the construction of airfields across the country. On April 12, 1928, Hermann Köhl , James Fitzmaurice and Ehrenfried Günther Freiherr von Hünefeld successfully crossed the transatlantic from east ( Baldonnel in Ireland) to west ( Greenly Island - Newfoundland) with a modified Junkers W 33 .

Flying boats
The age of the large flying boats began in the late 1920s , the most famous representatives of which were the Dornier Do X and Boeing 314 . The main areas of use were long transatlantic and Pacific flights.

The Short Mayo flying boat combination had been experimented with in England for transatlantic flights from 1937 onwards. The purpose of the Short-Mayo combination was to use a lightly fueled flying boat, in this case a Short-S.21, to carry a heavily loaded seaplane (a Short-S.20) at flight level and to release it there. This combination should optimize the relationship between performance, payload and fuel.

Catapult aircraft
A pioneer in catapult aircraft construction is Ernst Heinkel , who in 1925 set up a take-off runway (not yet a catapult) with an airplane on the Japanese battleship Nagato and personally commissioned it.

On a few large passenger ships like the Bremen , with the advent of the catapult technology, catapult aircraft were used, which were launched by means of a steam catapult. The aircraft were mostly used for fast mail delivery, such as the Heinkel He 12 and the Junkers Ju 46 . In the military sector, catapult aircraft were mainly used for aerial reconnaissance. Small machines such as the Arado Ar 196 were used from large warships and large catapult aircraft such as the Dornier Do 26 were used by Lufthansa for transatlantic airmail traffic from air base ships in the 1930s and as transport aircraft and sea during World War II -Range reconnaissance.

High-altitude aircraft
As early as 1937, the German Air Force began building high-altitude aircraft ; these were equipped with pressurized cabins and reached altitudes between 12,000 and 15,000 m. The most famous representatives were the Junkers Ef 61 , later the Henschel Hs 130 and the Junkers Ju 388 . They were used as high-altitude reconnaissance aircraft or high-altitude bombers, but only a few copies were built. As the first passenger aircraft with a pressurized cabin, the Boeing 307 Stratoliner allowed a flight over the weather and thus a significant increase in passenger comfort.

### 1939 to 1945

On June 20, 1939, the Heinkel He 176, the first test aircraft with an adjustable liquid rocket drive, took off . This aircraft is also the first to have a detachable cockpit capsule with a braking parachute as a rescue device. In an emergency, however, the pilot had to free himself from the capsule and jump off with the parachute. The aircraft reached a maximum speed of about 750 km / h.

The Heinkel He 178 was the first aircraft in the world to be powered by a turbine air jet engine. The first flight took place on August 27, 1939.

Due to the Battle of Britain, the fighter first came into focus. The two outstanding types of this time were the Messerschmitt Bf 109 and the Supermarine Spitfire , which were significantly increased in their performance through improvements in aerodynamics and also the performance of the engines in the course of their development.

The Heinkel He 280 was the world's first twin-engine aircraft ; it had two turbojet engines. It was also the first aircraft to be equipped with an ejection seat . The first flight took place on April 2, 1941. The ejector seat was first used as a rescue device on January 13, 1943, when the pilot had to catapult himself out of an He 280 that had become unable to fly due to icing.

The Allies used large four-engine bombers for strategic aerial warfare. Since attacks often had to be flown at night because of the German air defense, avionics found its way into air warfare. Devices for determining position, such as the GEE method, radar for navigation and night hunting, as well as radio devices were used. The fight led to ever greater altitudes and speeds. In order to be able to protect the bombers effectively, fighters with long range were developed, such as the North American P-51

The Arado Ar 234 B-2 from 1944 was the first four-engine bomber with an autopilot ( PDS ), followed. Shortly before the end of the war, the twin- engine flying wing Horten Ho IX was built . The outer shell was coated with a mixture of coal dust and glue to absorb radar rays.

With the Messerschmitt Me 163 , a rocket glider based on a glider was developed to readiness for use in mid-1944. Used as an object protection fighter, the aircraft impressed with its climbing performance, but was practically ineffective due to the circumstances of the mission.

During this time the airspeed increased up to the transonic range. Extensive research projects, especially on the German side, led to fundamental discoveries in high-speed aerodynamics, such as the use of wing arrowheads or the discovery of the area rule . The product of these efforts was the heavy jet bomber Junkers Ju 287 with negative sweep of the wings and application of the area rule.

The Japanese achieved outstanding success with their light and agile Mitsubishi Zero Sen in the Pacific. Only later developments in the USA made it possible to take action against the enemy with a chance of success. When the situation became more and more hopeless for Japan at the end of 1944, they invented kamikaze planes , the pilots of which suicidally steered the plane full of explosives onto Allied ships.

### 1945 until today

In 1947, the Bell X-1 officially broke the sound barrier as the first aircraft ; unofficially, according to reports from German fighter pilots, this was accidentally achieved in 1945 with a Messerschmitt Me 262 . The X-1 was an experimental aircraft with rocket propulsion , which was carried by a B-29 at an altitude of about 10 km and disengaged there, whereupon the rocket propulsion ignited and the aircraft broke the sound barrier.

The jet aircraft arms race began with the Cold War and the Korean War (1950–1953). On November 8, 1950, the world's first victory in a dogfight between jet aircraft in which a MiG-15 was shot down by a Lockheed P-80 . Basically, the P-80 and Republic F-84 were not up to the Soviet jets and were therefore soon replaced by the F-86 Saber .

With the commissioning of the British De Havilland DH.106 Comet for the airline BOAC in 1952, the age of jet turbines also began for commercial aircraft. However, the changing pressure loads were not adequately taken into account - the traffic now took place at greater heights and the load changes in the pressure cabin led to hairline cracks in the hull. When two machines of this type crashed in 1954, the causes had to be researched at great expense; it was material fatigue . This research benefited all designers. With the Tupolew Tu-104 , the Soviet Union established successful liner services from 1956. The Comet resumed service in autumn 1958 with a largely redesigned fuselage as the DH.106 Comet 4B, but only shortly before the Boeing 707 , which had a slightly longer range and could carry more than twice as many passengers. From 1962 onwards, the use of the more powerful and fuel-efficient turbofan engines improved the economy. At the beginning of the 1970s, the use of wide-body passenger aircraft such as the Boeing 747 "Jumbo-Jet" and the McDonnell Douglas DC-10 , followed later by Airbus series; the largest passenger aircraft today is the Airbus A380 .

With the beginning of the 1950s, the development of long-range strategic bombers that could also carry atomic bombs began . The most famous representatives were the Boeing B-52 , Convair B-58 , Myasishchev M-4 , the Tupolew Tu-95 and the Avro Vulcan . The B-58 was the first combat aircraft with a central on-board computer that combined the numerous assemblies.

In 1955, the French company Sud Aviation equipped its Alouette II helicopter with a 250 kW Turboméca Artouste shaft turbine and thus built the first helicopter with a gas turbine drive.

With the Hawker Siddeley Harrier , the serial production of vertical take-off VTOL aircraft began in 1966. However, almost all other VTOL aircraft did not get beyond the prototype stage. The USA is currently (2005) developing a new generation of V / STOL aircraft with the Lockheed Martin F-35 .

With the Vietnam War , Soviet and American aircraft collided again. The MIG 21 proved to be superior in many cases to the American McDonnell F-4 Phantom II. The Boeing B-52 was used for large-scale bombardments. The extensive use of helicopters, such as the CH-47 Chinook and Bell UH-1 , became increasingly important.

With the maiden flight of the Tupolev Tu-144 on December 31, 1968 and the Concorde on March 2, 1969, the episode of supersonic passenger air traffic began. The Americans had achieved a monopoly on conventional civil, turbine-jet powered passenger aircraft. The British and French wanted to break through this by building the Concorde. The increased oil price (it multiplied during the 1973 and 1979/80 oil crises ) made the Concorde uneconomical. The enormous fuel consumption was considered ecologically questionable. British Airways and Air France - both state-owned airlines at the time - were forced by their governments to buy the Concorde. The last flight of a Concorde took place on November 26, 2003.

The United States Air Force's Lockheed F-117 A Nighthawk was the world's first ready-to-use aircraft to make consistent use of stealth technology . The first F-117A was delivered in 1982. During the construction of the F-117, American engineers called it a "hopeless" case, suspecting that the shape of the aircraft would never allow it to fly. Before they got an official name, the engineers and test pilots called the unconventional aircraft that were hidden during the day to discovery by Soviet satellite to prevent "Cockroaches" ( cockroaches ). This designation is still widely used because, according to many, these aircraft are among the ugliest ever built. The aircraft is also known as the "wobblin goblin", especially because of its restless flight characteristics when refueling in the air . Due to its unstable aerodynamic properties, it can only be flown with the assistance of a computer.

On June 21, 2004, the SpaceShipOne rocket aircraft was the first privately financed suborbital space flight above 100 km. The machine was developed by Scaled Composites as part of the Tier One project in order to win the Ansari X-Prize competition of the X-Prize Foundation . This promised ten million dollars for those who would be the first to use an aircraft to transport two people or equivalent ballast to a height of more than 100 kilometers in addition to the pilot and to repeat this with the same aircraft within 14 days.

### Ongoing research and future

In order to address the issue of the necessary fuel savings, the possible use of flying wings is often discussed. This should also reduce noise pollution. A realistic research focus is the expanded use of lightweight materials such as CFRP and, to a certain extent, GLARE . New engines with heat recovery via heat exchangers are also being developed. The use of aerodynamic knowledge in z. B. the winglets or the Gurney flaps are examined. In the military sector, drones are becoming more and more popular, and completely new laser-based weapon systems are being tested with the Boeing AL-1 .

## Records

### Airspeed

The following table gives an overview of the speed records achieved by aircraft:

year Speed pilot nationality plane
1903 56 km / h Orville Wright United States Flyer 1
1910 106 km / h Leon Morane France Blériot XI
1913 204 km / h Maurice Prevost France Deperdussin monocoque
1923 417 km / h Harold J. Brow United States Curtiss R2C -1
1934 709 km / h Francesco Agello Italy Macchi-Castoldi MC72 (floatplane)
1939 755 km / h Fritz Wendel Germany Messerschmitt Me 209 V1
1941 1,004 km / h Heini Dittmar Germany Messerschmitt Me 163 (rocket fighter)
1947 1,127 km / h
Mach 1.015
Charles Elwood Yeager United States Bell X-1
1951 2,028 km / h Bill Bridgeman United States Douglas Skyrocket
1956 3,058 km / h Frank Everest United States Bell 52 X-2 (missile)
1961 5.798 km / h Robert White United States North American X-15 (rocket plane)
1965 3,750 km / h W. Daniel United States Lockheed SR-71 Blackbird (jet aircraft)
1966 7,214 km / h William Joseph Knight United States North American X-15 (rocket plane)
2004 11,265 km / h unmanned United States Boeing X-43A ( ramjet )

### size

Antonov An-225 - longest aircraft in the world

The Antonov An-225 "Mrija" cargo plane is the largest aircraft in the world . It has the greatest length, the highest takeoff weight, and the greatest thrust of any aircraft. Due to its capacity, the Airbus A380 is the largest passenger aircraft in the world (max. 853 passengers). Nevertheless, it is not the longest passenger aircraft: At 76.30 m, the Boeing 747-8 is the longest passenger aircraft in the world. The Scaled Composites Stratolaunch , which is intended for rocket launches, has the largest span .

The most powerful engine is the twin-engine Boeing 777-300 with 512 kN of thrust . It is difficult to determine the maximum range, as it can be increased for each aircraft with additional tanks (in extreme cases up to the maximum take-off weight). The aircraft with the longest standard range is the Boeing 777-200LR with 17,446 km. The longest range ever achieved without refueling belongs to the Voyager with 42,212 km.

Comparison of large aircraft:
Airbus A380 , Antonow An-225 , Boeing 747-8I , Hughes H-4 , Scaled Composites Stratolaunch
﻿﻿﻿﻿﻿
A380-800 A340-600 B747-8i B777-300ER Hughes H-4 Antonov An-225
length 72.7 m 75.3 m 76.3 m 73.9 m 66.7 m 84.0 m
span 79.8 m 63.5 m 68.5 m 64.8 m 97.5 m 88.4 m
height 24.1 m 17.3 m 19.4 m 18.6 m 25.1 m 18.1 m
Max. Takeoff weight 560 t 368 t 448 t 352 t 182 t 600 t
Range 15,000 km 13,900 km 14,815 km 14,600 km 4,800 km 15,400 km
Max. Number of passengers 853 419 605 550 750 Cargo plane
Thrust / power 4 * 311 kN
= 1244 kN
4 x 267 kN
= 1088 kN
4 x 296 kN
= 1184 kN
2 x 512 kN
= 1024 kN
8 2240 kW
= 17,920 kW
6 230 kN
= 1380 kN

## literature

• Ludwig Bölkow (Ed.): A century of aircraft. History and technology of flight . VDI, Düsseldorf 1990, ISBN 3-18-400816-9 .
• RG Grant: Flying. The history of aviation . Dorling Kindersley, Starnberg 2003, ISBN 3-8310-0474-9 .
• Ernst Götsch: Introduction to aircraft technology . Deutscher Fachverlag, Frankfurt am Main 1971, ISBN 3-87234-041-7 .
• Ernst Götsch: Aircraft technology. Introduction, basics, aircraft science. Motorbuchverlag, Stuttgart 2003, ISBN 3-613-02006-8 .
• Oskar Höfling : Physics, Volume II, Part 1, Mechanics - Warmth , 15th edition. Dümmlers, Bonn 1994, ISBN 3-427-41145-1 .
• Knaur's Lexicon of Natural Sciences . Droemersche Verlagsanstalt, Th. Knaur Nachf., Munich and Zurich 1969.
• How does this work? Meyers explained technology, Volume 1. Bibliographisches Institut, Mannheim and Zurich 1963.

Commons : Airplanes  - Collection of pictures, videos and audio files
Wiktionary: Airplane  - explanations of meanings, word origins, synonyms, translations

## Individual evidence

1. Aviator . duden.de
2. International Civil Aviation Organization (Ed.): Annex 2 to the Convention on International Civil Aviation . Rules of the Air. 10th edition. November 2016, p. 1–2 ( bazl.admin.ch [PDF; 878 kB ; accessed on July 12, 2017]).
3. The New Universal Lexicon . Bertelsmann Lexikon Verlag, 2007, ISBN 978-3-577-10298-8 , p.  284 .
4. ^ Heinz AF Schmidt: Lexicon of aviation . Motorbuch Verlag, 1972, ISBN 3-87943-202-3 .
5. Wilfried Copenhagen among others: transpress Lexikon: Luftfahrt . 4th revised edition. Transpress-Verlag, Berlin 1979, p. 255 .
6. Kathrin Kunkel-Razum, Birgit Eickhoff: Duden. Standard dictionary of German as a foreign language . Ed .: Bibliographisches Institut. 1st edition. Dudenverlag, Mannheim 2002 ("Airplane [...]: Aircraft with wings mounted horizontally on the sides of its fuselage.").
7. airplane. In: Digital dictionary of the German language . Retrieved on May 30, 2011 "Aircraft that usually consists of a fuselage equipped with a landing gear with horizontally mounted wings and a tail unit and whose flightability is achieved through dynamic lift"
8. David Anderson, Scott Eberhardt: Understanding Flight . 2nd Edition. McGraw-Hill, New York et al. a. 2009, ISBN 978-0-07-162696-5 (English, A Physical Description of Flight book excerpt [PDF]).
9. mdpi.com
10. a b boeing.com
11. a b FAST45 magazine from December 2009 ( Memento from December 26, 2012 in the Internet Archive )
12. a b boeing.com
13. also other types from other manufacturers from Page 69768
14. Jochim Scheiderer: Applied flight performance - An introduction to operational flight performance from take-off to landing , Springer-Verlag, 2008, ISBN 978-3-540-72722-4 , doi: 10.1007 / 978-3-540-72724-8 .
15. Dieter Scholz (2014): Flight control (PDF; 15 MB) script
16. ^ Wolfgang Leonhardt: Karl Jatho's first powered flight in 1903 . Books on Demand , Norderstedt 2002, ISBN 3-8311-3499-5
17. ^ Telegram from Orville Wright in Kitty Hawk, North Carolina, to His Father Announcing Four Successful Flights, 1903 December 17. In: World Digital Library . December 17, 1903, accessed July 21, 2013 .
18. The history of the fighter plane ( Memento from March 30, 2010 in the Internet Archive )
19. The end of Concorde , faz.net
20. to wobble = flutter, dangle, wobble