By akademiotoelektronik, 14/06/2022

Edge instrument (aeronautics) - Definition and explanations

Introduction

Les instruments de bord servent à présenter au pilote toutes les informations qui lui sont utiles au maintien en vol de son avion, à sa navigation, à ses communications avec les infrastructures de la gestion du trafic aérien et lui permettent d'interagir avec son avion (Un avion, selon la définition officielle de l'Organisation de l'aviation civile internationale...).

They are grouped on the dashboard (the dashboard is the element that indicates to the driver of a vehicle (automobile, boat), ...) as close as possible to the pilot. The four basic instruments are always arranged in the same way (in basic T configuration): the horizon (conceptually, the horizon is the limit of what can be observed, because of its own ...) Artificial in the center, the anemometer (anemometer - term of the 18th century, composed of the prefix anemo -...) on its left, the altimeter (an altimeter is a device allowing to measure the altitude.) To its right, the Directional gyro or road tray (the word "road" derives from Latin (via) Rupta, literally "track ...) below. This provision optimizes the visual circuit during the flight. The arrangement of the other instruments is relatively standard but varies from one plane to another. With generalization (generalization is a process which consists in abstract a set of ...) of screens bringing together all the information of the basic T on a single surface (a surface generally designates the superficial layer of an object. The term has ...) of visualization, the conventional instruments are kept on the on -board plates equipped with screens as well as rescue instruments to compensate for a possible failure of electronic systems.

They can be presented in classic form (see the first image below) or their information integrated into a screen (a monitor is a usual output device of a computer. This is the screen where ...) (See A319 cockpit storage position).The photos correspond to different planes in different flight situations;The instruments indications therefore do not correspond.

Les 4 instruments de base en T complétés par, en bas à gauche l'indicateur de virage, en bas à droite le variomètreLe poste de pilotage de l'Airbus (Airbus est un constructeur aéronautique européen et également un acteur majeur dans...) A319

The different types of instruments

On -board instruments use different systems for information and visualization: electromechanical, pneumatic, electronic, radioelectric instruments, etc.We could classify them according to their operating mode or their function (speed information (we distinguish :), attitude compared to the surrounding environment, navigation (navigation is science and all the techniques that allow:) or even simply in alphabetical order).The list below currently does not follow any of these logics.

Magnetic compass

It uses the terrestrial magnetic field (the earth has a magnetic field produced by the movements of its external nucleus --...) as a reference.

It consists of a reading telescope on a waterproof case filled with a liquid (the liquid phase is a state of the material. In this form, the material is ...) in which a mobile crew formed byA rose of caps and magnetic bars.It is an unprecise instrument which gives false indications as soon as the plane is not stable on a trajectory (the trajectory is the line described by any point of an object in motion, and ...)rectilinear, horizontal and at constant speed.It is nevertheless useful for adjusting or re -order the CAP curator (see compas and compass items).

In addition, it is influenced by the magnetic fields caused by the electrical equipment of the plane.Also, it is accompanied by a curve (in geometry, the word curve, or curve line designates certain sub-assemblies of ...) of calibration, established in standard conditions of tension (voltage is a force ofExtension.) Nearby equipment.

Finally, as for everything (all inclusive as a set of what exists is often interpreted as the world or ...) magnetic compass, it is necessary to take into account the declination of the magnetic pole (a magnetic pole is a point of "convergence"Magnetic field lines present ...) and local influences.

Aerodynamic (or anemobarometric) instruments)

Ils utilisent les propriétés liées à la pression (La pression est une notion physique fondamentale. On peut la voir comme une force rapportée...) de l'air (L'air est le mélange de gaz constituant l'atmosphère de la Terre. Il est inodore et...) environnant. Une sonde (Une sonde spatiale est un vaisseau non habité envoyé par l'Homme pour explorer de plus près des...) (appelée tube de Pitot) disposée sur l'avant du fuselage (Le fuselage désigne l'enveloppe d'un avion qui reçoit généralement la charge...) ou de la voilure permet de capter la pression totale à un endroit où la pression créée par l'écoulement de l'air autour (Autour est le nom que la nomenclature aviaire en langue française (mise à jour) donne...) de l'avion (vent relatif) et la pression atmosphérique (La pression atmosphérique est la pression de l'air en un point quelconque d'une atmosphère.) régnante s'additionnent. Des prises d'air disposées sur le côté du fuselage de l'aéronef (Un aéronef est un moyen de transport capable d'évoluer au sein de l'atmosphère...) permettent de mesurer la pression atmosphérique pure (pression statique) à un endroit où le déplacement (En géométrie, un déplacement est une similitude qui conserve les distances et les angles...) de l'air n'a aucun effet. La vitesse de l'avion par rapport au vent peut alors être déduite de la différence entre pression totale et pression statique. Cette différence représente la pression dynamique (Le mot dynamique est souvent employé désigner ou qualifier ce qui est relatif au mouvement. Il...), proportionnelle à la vitesse de l'avion par rapport à l'air. Le système installé sur les aéronefs est désigné par le terme anémobarométrique (voir plus bas anémomètre).

Altimètre

An altimeter is a simple barometer (the barometer is a measurement instrument, used in physics and ...) (exactly the same which serves meteorologists to read atmospheric pressure) which is calibrated to directly indicate altitude information (The altitude is the vertical elevation of a place or an object compared to a level ...) expressed in feet or meters.

Scientists have developed (spelling) a scale, which links static pressure directly with altimetry information.

We consider in atmosphere (the word atmosphere can have several meanings :) standard that 1 HPA (hectopascal) corresponds to 27 ft (feet).For the record (in general, memory is the storage of information. It is also the memory ...), the reference of the standard atmosphere (or OACI type atmosphere) was carried out at the level of theSea (sea level is the average height of the sea surface, compared to a level of ...) (berre pond) at a temperature (temperature is a physical quantity measured usingA thermometer and ...) of 15 ° C, 0 % humidity (humidity is the presence of water or water vapor in the air or in a substance ...) and an atmospheric pressure of1,013.25 hpa.

Atmospheric pressure is constantly changing;It is therefore necessary to reset the altimeter to have correct information.

Different altimetric calts: (see language (aeronautics), q code)

This timing is widely used for line planes, as well as for the delimitation of fixed air areas, such as TMA, CTR, and other areas of approaches or prohibitions.

Anémomètre (badin)

The first speed measurement instruments consisted of a vertical lever articulated around a pivot and supporting a rectangular palette oriented perpendicular to the flow of the relative wind and a needle.It was kept in zero position by a calibrated spring (peson principle).Wind pressure made the needle move to a dial to indicate the air speed.Designed in 1910, it was appointed indicator was the name of its inventor Albert was.

This system was called a deflection antenna on the SV4 Stampe (the SV-4 Stampe is a biplane designed for training which was later used for aerobatics ...).In 1965, some Tiger Moth were still equipped with it.

Aujourd'hui, le dispositif utilisé est un instrument appelé badin en France (en 1911, du nom de son inventeur, Raoul Badin) associé au tube de Pitot (Le tube de Pitot et l'antenne de Prandtl sont des systèmes similaires de mesure de vitesse des...). C'est un manomètre (Un manomètre est un instrument servant à mesurer une pression.) étalonné en fonction de la loi de Bernoulli (En mathématiques, la distribution de Bernoulli ou loi de Bernoulli, du nom du...) qui détermine la « pression dynamique » qui est égale à la différence entre la pression totale et la pression statique. Cette pression dynamique, est fonction de la vitesse de l'avion par rapport à l'air et permet d'afficher une information de vitesse air sur le badin. Elle est généralement mesurée en nœuds, mais, sur quelques avions français et sur les avions russes, elle est donnée (Dans les technologies de l'information, une donnée est une description élémentaire,...) en kilomètres (Le mètre (symbole m, du grec metron, mesure) est l'unité de base de longueur du Système...) par heure (L’heure est une unité de mesure du temps. Le mot désigne aussi la grandeur...). L'anémomètre donne la vitesse indiquée (Vi) ou vitesse lue. Cette vitesse correspond à la vitesse propre (Vp) ou vitesse vraie à la pression de 1 013,25 hPa (au niveau de la mer en atmosphère standard) et à la température de 15 °C. Avec la baisse de la densité (La densité ou densité relative d'un corps est le rapport de sa masse volumique à la...) de l'air, donc en montant, la vitesse propre est supérieure à la vitesse indiquée (une approximation (Une approximation est une représentation grossière c'est-à-dire manquant de...) peut être faite en ajoutant 1 % par tranche de 600 pieds au-dessus de la surface 1 013 hPa).

The colored arches (color is the subjective perception that the eye of one or more wave frequencies ...) indicate the maximum gear areas:

See aeronautical speeds.

For planes flying at speeds close to that of sound and beyond, other laws are applicable and, therefore, other instruments: the machmeter.

Variomètre

Date of creation: 1928 in Germany. In its classic version, this instrument uses static pressure variations to indicate altitude variations, that is to say vertical speeds.From air to outdoor static pressure is stored in a bottle called capacity that is put at pressure with time (time is a concept developed by humans to understand ...) known.Pressure in capacity is therefore late compared to current pressure.At the time of measurement, the instrument makes the difference between external pressure and capacity pressure.Note that the variideus works with a slight delay time, due to the time to fill the capacity.

There is a different version (in mathematics, the different is defined in algebraic theory of ...), where the instrument is called for total energy (or compensated variometer). It indicates the variation in the sum of kinetic energy (kinetic energy (also called in the ancient writings live live, or vive force) is ...) (due to speed), and potential energy ( due to altitude). It is used for the practice of sailing (theft is a leisure and competition activity during which ...), where it is interesting to know the energy gain of the glider (a glider is a Aerodyne which is, by definition, devoid of engine. It exists ...) due to the vertical speed (the vertical is a line parallel to the direction of the gravity, given in particular by the ...) of the mass (the term mass is used to designate two quantities attached to an air ...) of air, even during a resource. Indeed in flight, the absence of an engine (an engine (from the Latin mōtor: "the one that stirs") is a device ...) makes the only possible cause of an increase in energy is a mass ascending air (friction is neglected). The total energy variometer therefore indicates the energy variation translated into vertical speed. When taking speed preceding the takeoff (takeoff is the transitional phase during which an aircraft goes from the state ...), it indicates a positive value although the vertical speed is zero. Finally, there are so -called “clean” variometers which deduce the vertical speed of the air mass, as a function of the variations in total energy and the characteristics of the glider.

Gyroscopic instruments

They use the properties of the bodies in rapid rotation that are gyroscopes: fixity of the axis of the rotor in absolute space, gyroscopic torque, precession (precession is the name given to the gradual change of orientation of the axis of rotation rotationof a ...).Classic gyroscopes are trained by a pump (a pump is a device for sucking and repressing a fluid.) With a vacuum (the vacuum is usually defined as the absence of material in a space zone.) Or an electric motor whichgives them a very high speed of rotation (10,000 rpm in the first case, 20,000 rpm in the second).

Gyro compas / gyro directionnel

It is a gyroscope (a gyroscope (from the Greek "who looks at the rotation") is a device that exploits ...) with two degrees of freedom which allows you to keep a CAP reference in a much more precise way than'A magnetic compass.It is enslaved to a flow valve (the word flow (from the Latin fluxus, flow) generally designates a set of elements ...) (in English: valve flow) which allows it to be remedy automatically according to the magnetic field (In physics, the magnetic field (or magnetic induction, or land density ...) it is also called the road tray.

Horizon artificiel

It is a gyroscope with two degrees of freedom which allows you to visualize the attitude of the plane compared to its axes of roll and pitch and more precisely of their angles with a horizontal plane: plate and inclination.

Indicateur de virage et de dérapage (bille-aiguille)

The turn indicator is a gyroscope to a degree of freedom (the concept of degree of freedom covers several concepts in science and engineering :) which allows you to visualize the turn rate (and not the inclination) of the plane.

It is associated with a ball which moves in a curved tube according to the apparent vertical and which visualizes the slippage of the plane. The ball just works by gravity (gravitation is one of the four fundamental interactions of physics.). Indeed, when the slippage is zero and the symmetrical flight, the relative gravity (equivalent gravity created by the weight (the weight is the force of gravity, of gravitational and inertial origin, exerted by ...) and the force ( The word force can designate a mechanical power over things, and also, metaphorically, a ...) centrifugal) is according to the vertical axis of the plane. If the relative gravity forms an angle (in geometry, the general notion of angle is available in several concepts ...) with the vertical of the glider, it is that there is a slippage. In flight, the indication (an indication (from the Latin indication: indicate) is a advice or a recommendation, written ...) given by the ball is often doubled by a woolen thread glued to the canopy. The wool wire is glued by one of its ends, and the ten centimeters of the wire (often red color) moves with the relative wind. The wire then indicates the angle between the relative wind and the axis of the glider, which is the definition (a definition is a discourse that says what a thing is or what a name means. Hence the .. .) Spew or slide.

Centrale à inertie (Une centrale à inertie ou centrale inertielle est un appareil de navigation de précision...)

The inertia plant (the inertia of a body stems from the need to exercise a force on it to modify its ...) (in English inertial navigation system, INS) is made up of two gyroscopes with three degrees of freedom and a trihedron of accelerometers. After a phase (the word phase can have several meanings, it used in several areas and ...) of stabilization, all the movements of the aircraft around the reference position are known. It therefore replaces the artificial horizon and the Directional Gyro. By integration of the accelerometers signals, the speeds of the aircraft according to the three axes are calculated in the terrestrial repository. The position of the plane is thus calculated always in the terrestrial repository, thus disregarding (in philosophy, abstraction designates both an operation which consists in isolation by ...) movements due to air currents. The position drift is of the order of the sea mile per hour. This system is therefore insufficient to determine the altitude with sufficient precision. To correct defects, there are several methods including barometric coupling or coupling with a GPS. Line planes to cross the oceans (stylized oceans Ωcéans is a French documentary produced by ...) by borrowing MNPS spaces are equipped with three power plants of this type. There are two types of power plants, those that are equipped with mechanical or modern gyroscopes that are equipped with gyrolasers.

Gyrolaser

A gyrolaser is composed of a circuit of light (the light is the set of electromagnetic waves visible by the eye ...) traveling a triangle (in Euclidean geometry, a triangle is a flat figure, formed by three points. .) Equilateral. The light source (laser radius) is applied in the middle of the base of the triangle, or is separated into two beams towards the two lower angles of the triangle where two mirrors are placed which redirect the two beams of light towards the third summit. The speed of propagation of light being constant, if the triangle is animated by a rotation movement in its plane, the distance traveled in the two branches becomes different (Sagnac effect). Thanks to the properties of radiation (radiation, synonymous with radiation in physics, designates the process of emission or ...) laser (a laser is a device emitting light (electromagnetic radiation) ...), we then observe An interference (in wave mechanics, we speak of interference when two waves of the same type ...) at the top of the triangle. A detector (a detector is a technical device (instrument, substance, material) which changes ...) photoelectric can count and determine the direction of scrolling of the lines of this interference, whose frequency (in physics, the frequency generally designates the Measurement of the number of times a ...) is proportional to the speed of rotation of the triangle on itself. By going up three devices of this type according to a trihedral, and by treating the signals, it becomes possible to determine all the movements of an aircraft according to its three axes as with a mechanical gyroscope (in current language, mechanics is the domain of Machines, engines, vehicles, organs ...). By adding the accelerometers and the processing of their signals, an inertia plant has been reconstructed.

Instruments électromagnétiques