Airplane compass. Airplane magnetic compass
The magnetic compass in an airplane determines and maintains the heading of the flight direction. An aircraft's heading is the angle between the longitudinal axis of the aircraft and the actual direction along the meridian. It is customary to count the course from the northern direction of the meridian. From the meridian, the angle is measured clockwise to the longitudinal axis of the aircraft. As you know, the course can be magnetic, compass and true.
The operating principle of each compass is based on the action of a magnetic needle, which is installed in the plane of the magnetic meridian in the north direction. After determining the magnetic meridian using a compass, the angle to the longitudinal axis of the aircraft is measured - this is the magnetic course. It should be noted that modern compasses installed in the cockpit are structurally different from field compasses. The construction of aviation compasses uses materials that exhibit weak magnetic or diamagnetic properties. The main structural parts of an aircraft compass are: bracket, heading line, deviation device, card, bowler.
A cauldron is a vessel made of aluminum or copper and hermetically sealed with a glass lid. The inside of the pot is filled with liquid, usually naphtha or wine alcohol. Replacing or adding fluid significantly impairs the operation of the device and can lead to complete unusability. The liquid serves as a damper and dampens the vibrations of the cartridge, and also reduces the pressure of the stud on the firebox.
In the middle of the pot there is a column on which the card is attached. A card is a complex of connected magnets that are directed one to one with the same charged pole. In most cases, aviation compass cards consist of two horizontal and two vertical magnets. The magnets must be positioned with a high degree of accuracy, since the slightest shift can lead to deviations from the true values. The upper pairs of magnets have a significantly larger magnetic moment than the lower ones, in a ratio of 15 CGSm to 12 CGSm. As a result, the total moment should be no lower than 54-56 CGSm. The quality of the compass depends on the correct selection of magnets and their sizes. An arrow is installed at the end of the card, which points to the side of the horizon; it serves for orientation in the flight map. The overall magnetic system is designed for 200 hours of engine operation. There is a heading line inside the bowler, which is used as an index when calculating the course.
The airplane compass bowl is filled with liquid; when the temperature changes, its volume changes, which can lead to an error in the instrument’s readings. To avoid this situation, a compensation chamber is installed.
This design is used in all modern aircraft compasses. There are differences, they manifest themselves mainly in the depreciation system or the shape of the cartridge. Lighting devices are also used for night operation.
The practical use of a compass on an airplane shows that its use is different for the navigator and the pilot. The pilot uses this device to select the correct flight direction. It is used to analyze flight fidelity and detect course deviations. As for the navigator, he uses the compass to quickly calculate the flight map, as well as to analyze the course. The navigator's compass is considered to be the main one on board an aircraft. Because of this, there are two types of magnetic aviation compasses that are installed on the board of an aircraft - the main one and the directional one.
Aircraft magnetic compass deviation
Even at the dawn of aircraft construction, all aircraft, without exception, were equipped with magnetic compasses, which did an excellent job of determining the magnetic heading of the aircraft. However, with the further development of multi-engine units with a large part of electronics, significant problems arose with the operation of compasses. All electromagnetic vibrations emanating from other instruments significantly affected the operation and accuracy of the instrument. In some cases, the compass readings could differ from the true ones by ten degrees, and this is a lot to determine the correct direction of flight. During flight, all compasses experience accelerating and magnetic influences, which lead to deviation.
Magnetic deviation. Each compass system receives influence from various magnetic fields both from the Earth itself and from other sources of magnetism directly on board the aircraft. These can be radio systems, electrical wiring and its fields, as well as the steel mass of the structure itself. Because of this, compasses on board an aircraft have errors in their readings, which are commonly called magnetic deviation.
Constant magnetic deviation on board an aircraft is caused by inaccurate installation of the compass itself. It is characterized by dependence on the magnetic course itself.
The semicircular magnetic deviation in the compass reading can be caused by the so-called solid iron, which has a permanent magnetic charge. Readings are also affected by more permanent sources such as electrical appliances and wiring components. They have a constant force and direction of influence on the compass.
There is also such a thing as inertial deviation, which arises due to bumpiness, changes in speed, turn, all this creates forces that affect the readings of the magnetic compass on board the aircraft. All this makes it much more difficult to work with the device and calculate the correct direction.
Nevertheless, when making compasses and the aircraft themselves, designers take into account all these influences and deviations. To reduce third-party influences on the accuracy of compass readings, systems are used that can significantly reduce all of the above mentioned influences on the accuracy of readings.
§ 21. General information about magnetic compasses
Purpose. The compass is used to determine and maintain the aircraft's heading. Airplane heading called the angle between the north direction of the meridian and the longitudinal axis of the aircraft. The course is counted from the northern direction of the meridian in a clockwise direction to the direction of the longitudinal axis of the aircraft. The course can be true, magnetic and compass, depending on the meridian from which they are counting (Fig. 116).
The course measured from the geographical meridian is called true course. The course measured from the magnetic meridian, i.e. from the direction shown by the arrow, free from the influence of the iron and steel masses of the aircraft, is called magnetic course. The course measured from the compass meridian, i.e. from the direction shown by the compass needle located near aircraft iron and steel, is called compass course.
The discrepancy between the compass and magnetic meridians is explained by the fact that the magnetic needle of the compass is deflected under the influence of steel parts of the aircraft. The angle between the northern directions of the magnetic and compass meridians is called compass deviation. By analogy with declination, deviation is called eastern (+), if the northern end of the magnetic needle deviates to the right of the meridian, and western (-), if the northern end of the arrow deviates to the left of the meridian. Compass deviation (error) is a variable value for each aircraft heading.
The effect of steel aircraft parts on a compass magnet is explained by the fact that the lines of the earth's magnetic field, passing through various steel parts of the aircraft, magnetize them. As a result of the addition of the main earth's magnetic field and all induced fields in the steel and iron parts of the aircraft, a magnetic field of the aircraft is established. It is somewhat different from the earth's magnetic field in strength and direction. Every change in the aircraft's attitude causes a change in the aircraft's magnetic field.
The compass needle is set in the direction of the total magnetic field of the Earth and the aircraft.
When performing aeronautical calculations, you often have to move from one course to another. To move from a compass course to a magnetic course, the deviation value is algebraically added to the compass course:
MK = KK + Δ k
To switch from a magnetic course to a compass course, the deviation value is algebraically subtracted from the magnetic course:
KK = MK - Δ k
To move from the magnetic course to the true one, the magnetic declination is algebraically added to the magnetic course:
IR = MK + Δ m
To move from the true course to the magnetic one, the value of the magnetic declination is algebraically subtracted from the true course:
MK = IR - Δ m
Elements and characteristics of compasses.
The main part of the compass is the magnetic compass system, called cards(Fig. 117). The compass card is a thin brass or aluminum disk divided into 360 degrees. This disk, or dial, has a hollow float that reduces the weight of the card in the liquid. A pair or several pairs of magnets are symmetrically attached to the disk under the float. The magnet axes are parallel to the 0-180° line of the limb, called card axis. The magnetic poles of the same name are directed in one direction. The compass card rests with a pin on a cup made of hard stone (sapphire, agate), embedded in the compass column and called firebox
Inside the cauldron, which is an aluminum vessel hermetically sealed with a glass lid, there is a column that serves as a support for the compass card. Under the glass is exchange line- a thin wire installed against the dial and serving as an index when calculating the course of the card on the compass. Liquid is poured into the pot to dampen the vibrations of the cartridge. The pot is connected to a membrane chamber made of thin corrugated brass. The chamber serves to compensate for changes in liquid volume when temperature changes.
The disassembled diagram of the magnetic compass structure represents the basis of the designs of all aviation compasses. Different types of compasses differ only in devices for shock absorption, scale illumination, the shape of the card, compensation devices and other details.
The pilot must fly the plane along a strictly specified course; therefore, the compass intended for the pilot must, first of all, be convenient for monitoring the course of the aircraft. The pilot's compass is called travel It is the navigator's responsibility to calculate the aircraft's heading, and the navigator's compass must allow quick and accurate digital readings of the aircraft's heading at any given moment. The navigator's compass is called the main thing.
The magnetic compass card is the most critical component, and the operation of the compass as a whole depends on its quality. If you remove a card from the meridian, it tends to return to its original position. But during its reverse movement, the card will pass the zero position, deflect in the opposite direction and, like a pendulum, will oscillate in one direction or another.
In the absence of friction and fluid resistance, the rocking of the card would continue indefinitely. Such oscillations are called undamped.
In reality, frictional forces and fluid resistance act on the compass card, as a result of which the range of vibrations (amplitude) gradually decreases. Such oscillations are called fading. The ratio of two adjacent amplitudes is called damping decrement. Obviously, for a compass card this value is always greater than one.
The magnitude of the decrement and the period of oscillation characterize the compass card; the larger the decrement and the shorter the period, the faster the card is set to the equilibrium position; The larger the damping decrement, the sooner the compass will return to the zero position. In fig. 118 shows the decay graphs of three compasses. The attenuation decrements of two of them are 2.5 and 5 with equal periods. A compass with a decrement of 5 will return to the meridian sooner than a compass with a decrement of 2.5. 
Fig. 118. Decay graphs of magnetic compasses.
If the force causing the damping is strong enough, then the card returns to its equilibrium position without making a single oscillation. This compass is called aperiodic. The aperiodicity of compass cards is achieved by lightening the entire system of the card and attaching four to eight calming wires to the card, which, when the card moves in the liquid, create resistance to this movement, which quickly increases with increasing speed of the card.
If you tilt the compass card at a certain angle, then due to friction in the firebox, the card does not return exactly to its original position. The amount by which the card does not reach its original position is called stagnation of the cards. The greater the magnetic moment of the card and the greater the horizontal component of the earth's field, the less the stagnation of the card. Stagnation increases with increasing friction of the cartridge pin on the firebox. The quality of the compass card is higher, the less its stagnation. Due to the vibration of the compass, the amount of stagnation in flight at normal temperatures rarely exceeds 1°.
Compass hobby is the angle through which the liquid drags the compass card when the compass is rotated 360°. Compass drift is an extremely undesirable phenomenon, since when the plane changes course, it is impossible to determine the angle of rotation from the card drawn behind the pot. The larger the surface of the card and the closer it is to the walls of the pot, the greater the fascination. Compass drag is one of the reasons that prevents the otherwise advantageous increase in fluid resistance.
The card, which is the sensitive element of the compass, consists of a system of magnets, a dial, or dampers replacing it, a firebox, or pin, and a float. In fig. P9 shows the device of a card with a vertical dial. Such cards have a small attenuation decrement, approximately equal to 3-3.5. 
Fig. 119. Arrangement of a card with a vertical limb:
1-magnets, 2-column, 3-firebox, 4-float, 5-pin, 6-limb,
The center of gravity of the card should be below the fulcrum, i.e. below the tip of the pin. The limb and float are made of thin material. The pin is made of iridium or hard steel and has a radius of curvature at the tip of 0.1 - 0.2 mm, since a sharper pin can damage the firebox. A special spring washer prevents the card from jumping off the column.
The float is soldered with tin and acid-free flux. All parts of the card, except the pin, are coated with a special protective varnish.
The dial is graduated 360°. The division price depends on the diameter of the dial and the purpose of the compass; for pilot's compasses, the division value is 2-5°, for navigation compasses 1-2°.
For compasses with a large damping decrement, there is no dial on the card, and instead there are several damping antennae located radially (Fig. 120).
The compass column (Fig. 121), which supports the card, also serves to absorb vibrations caused by vibration of the aircraft. The radius of curvature of an agate or sapphire firebox is 2-3 mm. The column is installed at the bottom of the compass bowl. 
The inner surface of the bowl, made of aluminum casting, is made smooth to reduce fluid entrainment when the aircraft turns. The pot is impregnated with liquid glass or a special varnish to increase the tightness. A leaking pot will cause naphtha to leak and cause a bubble to form.
The kettle must be designed to compensate for changes in liquid volume when temperature changes. This compensation is carried out using a membrane box, as indicated in Fig. 117, or through a special compensation chamber (Fig. 122). The volume of the chamber must ensure normal operation of the compass at temperatures from +50 to -70°C. The compensation chamber slightly increases the dimensions of the compass; but its use is the best way to compensate for changes in fluid volume. The liquid that fills the pot and surrounds the card serves to dampen its vibrations and reduce the friction of the firebox on the pin. Previously, compasses were filled with alcohol in various aqueous solutions; Currently, compasses are filled with naphtha.
The pots have a special hole for filling with liquid, closed with a metal stopper with a lead gasket. Some compasses have a special chamber for installing a light bulb to illuminate the instrument scale. Sometimes the light bulb socket is mounted on a small bracket outside the compass.
The heading line, which is a thin wire, is attached to the compass bowl with screws. In compasses with a horizontal card, plane-parallel glass is installed. Compasses with a vertical card use spherical or, more often, cylindrical glass. To avoid distortions and errors when taking readings, the glass must be geometrically correct.
§ 22. Types of compasses, their design and installation
A universal type of compass is the A-4 compass, which is used as a traveling and main compass. Pilots also use the KI-11 compass as a travel compass.
Compass A-4 (Fig. 117) is used as the main compass in the navigator's cabin and as a guide in the pilot's cabin.
The compass card has two cylindrical magnets attached to a float. The countdown is made using four dampers, on which the numbers 0, 1, 2 and 3 are printed, indicating hundreds of degrees. The angle between dampers 0 and 3 is 60°; the angle between the remaining pairs of dampers is 100°. A centigrade scale with divisions of 1° is attached to the compass bowl; The 50° division replaces the heading line.
When counting the heading, hundreds of degrees are shown by the number on the damper, set opposite the scale, tens and units - the number on the scale opposite the damper.
In addition to these dampers, there are two more shortened dampers located parallel to the magnets of the card, i.e. along the line of the magnetic meridian. These dampers form the compass needle, with the north end of the needle colored red. The purpose of the arrow is to show the general direction to the north, since the damper with the number 0 does not show this direction.
For better damping, the compass card is made in the form of a skirt. The column is equipped with spring shock absorption.
A deviation device is attached to the bottom of the pot to compensate for semicircular deviation (the design and principle of operation of the deviation device are described below, see § 23). The compass pot is filled with naphtha.
Volume compensation of the A-4 compass is arranged as follows. In the upper part of the kettle there is an additional annular chamber, partially filled with naphtha (compensation chamber). This chamber communicates with the pot through an annular cutout. The liquid level in the compass bowl is always above the bottom surface of the glass. The lower surface of the glass has some convexity to remove air bubbles that appear during aircraft evolutions. The decrease in the volume of liquid in the kettle, which occurs as the temperature drops, is compensated by the liquid coming from the compensation chamber. Since changes in atmospheric pressure do not affect changes in the volume of liquid inside the pot, the compass can work at any altitude.
The compass is illuminated by an electric light bulb, powered by the on-board network. The light bulb shines into the end of the compass glass and illuminates the instrument scale.
The time to reach zero when deviating from the magnetic meridian by 90°, which characterizes the moment of inertia, is 5 seconds. at normal temperature. The settling time of the compass when deviating by 90° from the magnetic meridian is 25 seconds. at normal temperature.
The drag at an angular velocity of 710 rps is up to 3° at normal temperature. The compass works fine at rolls up to 17°.
The weight of a card in air is 10.5 g, in naphtha - up to 2 g.
The compass has two magnets made of iron-nickel-aluminum steel with a diameter of 3 mm and a length of 32 mm. The magnetic moment of each magnet is at least 80 units. CCSM.
The KI-11 compass (Fig. 119) is a travel compass and is installed in the cockpit. The compass has a vertical scale on the card. The dial of the device is divided into divisions of 5° with digitization every 30°.
The course is marked directly on the card against the heading line installed between the glass and the card. The compass card is float with one pair of magnets. The column is damped by a coil spring. Volume compensation is carried out using a compensation chamber located in the upper part of the kettle. Due to the fact that changes in atmospheric pressure do not affect the volume of liquid inside the pot, the compass can work at high altitudes.
The compass glass is a convex-concave lens, as a result of which the card appears slightly enlarged.
The lamp for illuminating the KI-11 compass is designed to be powered from the on-board network of the aircraft.
The compass is installed on the pilot's instrument panel so that when the aircraft is in the flight line, the compass card is strictly horizontal. The compass is installed on the dashboard in a hole with a diameter of 80 mm and secured using a fastening ring.
The compass damping decrement is about 3.5; calming time is about 25 seconds; the entrainment angle at a compass rotation speed of 1/10 rpm is 15-20°; stagnation is less than 0.5°.
The time to reach zero when deviating from the magnetic meridian by 90° is about 3 seconds. at normal temperature. The calming time for a deviation of 90° from the magnetic meridian is about 20 seconds. at normal temperature. The compass damping decrement is about 3.5.
The drag angle at a compass rotation speed of 1/10 rps is 15-20° at normal temperature.
The weight of a card in air is 9.5 g, in naphtha - about 2 g.
The magnets in the KI-11 compass are the same as in the A-4 compass.
Installation of compasses on an airplane. When installing a compass on an airplane, the following requirements must be considered.
The pilot must have a clear view of the compass without changing his head position. It is best to use a compass with a vertical card mounted on the top of the instrument panel directly facing the pilot.
For the navigator, it is best to install the compass directly in front of his workplace, slightly below eye level.
It should be remembered that the action of a piece of steel on a magnetic needle is inversely proportional to the cube of the distance between them; therefore, sometimes it is enough to move the compass away from the source of the magnetic field by a few centimeters to obtain a noticeable decrease in deviation.
Electrical devices on an airplane must be shielded, and the DC wiring must be bifilar, that is, the wires from the positive side of the on-board network must be twisted together with the wires from the negative side.
The installation of the compass should provide easy access to the deviation device and the locking screw of its mounting ring.
The heading line of the compass must be in the plane of symmetry of the aircraft or be parallel to it.
Date of publication on the website: November 20, 2012
About "actions of a piece of steel".
I remember the defect from the incorrect reading of KI-13. On modern aircraft it is installed in the center, at the top, on the canopy frame, the most optimal location. Moreover, for a long time no one cared about this, this is why you need a compass on an airplane, until someone became interested in why our “bull’s eye” points “in the wrong direction at all” :-)
The reason turned out to be that the roller of one of the blind flight curtains was made of steel during repairs.
AVIATION TRANSPORT Statistics say that aviation is the safest mode of transport. On average, just over three thousand people die in aviation accidents worldwide each year. For comparison, I will cite the same statistics of road accidents,
From the book Everything about everything. Volume 1 author Likum ArkadyWho invented the compass? The simplest form of compass is a magnetic needle mounted on a rod so that it can rotate freely in all directions. The needle of such a so-called compass points to “north”, by which we mean the North Magnetic Pole
From the book 100 Great Inventions author Ryzhov Konstantin Vladislavovich21. COMPASS The compass, like paper, was invented by the Chinese in ancient times. In the 3rd century BC. Chinese philosopher Hen Fei-tzu described the structure of a contemporary compass this way: it looked like a pouring spoon made of magnetite with a thin handle and spherical, carefully
From the book Great Soviet Encyclopedia (AS) by the author TSB From the book Great Soviet Encyclopedia (AV) by the author TSB From the book Great Soviet Encyclopedia (YOU) by the author TSB From the book Great Soviet Encyclopedia (GI) by the author TSB From the book Great Soviet Encyclopedia (GO) by the author TSB From the book Great Soviet Encyclopedia (KA) by the author TSB From the book Great Soviet Encyclopedia (KO) by the author TSB From the book Great Soviet Encyclopedia (MO) by the author TSB From the book Great Soviet Encyclopedia (PO) by the author TSB From the book 100 Famous Inventions author Pristinsky Vladislav Leonidovich From the book Great Encyclopedia of Technology author Team of authors From the author's book From the author's bookAviation rocket engine An aviation rocket engine is a direct reaction engine that converts some type of primary energy into the kinetic energy of the working fluid and creates jet thrust. The thrust force is applied directly to the rocket body
AVIATION COMPASS
compass, an aeronautical instrument indicating to the pilot the course of the aircraft relative to the magnetic meridian (magnetic compass, gyromagnetic compass), a given direction (gyro-semi-compass) or the direction to a radio beacon (radio compass, radio-semi-compass) and relative to any celestial body (astronomical compass).
Great Soviet Encyclopedia, TSB.
2012See also interpretations, synonyms, meanings of the word and what an AVIATION COMPASS is in Russian in dictionaries, encyclopedias and reference books:
- COMPASS in Miller's Dream Book, dream book and interpretation of dreams:
Seeing a compass in a dream means that you will be forced to fight with limited means, with your hands tied, thus doing... - COMPASS in the Directory of Constellations, Latin names.
- COMPASS in the Big Encyclopedic Dictionary:
(lat. Pyxis) constellation of the Southern ... - COMPASS JOURNAL. in the Encyclopedic Dictionary of Brockhaus and Euphron:
scientific and literary magazine of the Naval Cadet Corps; has been published as a manuscript since March 1905 as articles accumulate, monthly if possible. ... - COMPASS in the Encyclopedic Dictionary of Brockhaus and Euphron.
- COMPASS
[Dutch kompas] a device for orientation relative to the cardinal points on land, at sea and in the air; consists of a magnetic needle rotating... - COMPASS in the Encyclopedic Dictionary:
a, m. (sailors have a compass) A device for determining the cardinal directions, the magnetized arrow of which always points to the north. Compass - related... - COMPASS in the Encyclopedic Dictionary:
, -a (sailors have a compass, -a), m. A device for determining the cardinal points (sides of the horizon). Magnetic card (with a magnetized pointer, always ... - COMPASS
COMPASS (lat. Pyxis), constellation South. ... - COMPASS in the Big Russian Encyclopedic Dictionary:
COMPASS (German: Kompass), a device indicating the direction of geogr. or mag. meridian; serves for orientation relative to the sides of the horizon. There are magnetic, mechanical. (gyrocompass), ... - AVIATION in the Big Russian Encyclopedic Dictionary:
AVIATION TRANSPORT, see Transport... - AVIATION in the Big Russian Encyclopedic Dictionary:
AVIATION SPORTS, collect. name aviation kinds of sports. See Aeromodelling, Parachuting, Gliding, Airplane... - COMPASS in the Encyclopedia of Brockhaus and Efron.
- COMPASS in Collier's Dictionary:
a device for determining horizontal directions on the ground. Used to determine the direction in which a ship, aircraft, or ground vehicle is moving; ... - COMPASS
compa"s, compa"sy, compa"sa, compa"sov, compa"su, compa"sam, compa"s, compa"sy, compa"som, compa"sami, compa"se, ... - COMPASS in the Complete Accented Paradigm according to Zaliznyak:
ko"mpas, ko"mpas, ko"mpas, ko"mpasov, ko"mpas, ko"mpas, ko"mpas, ko"mpas, ko"mpas, ko"mpas, ko"mpase, ... - AVIATION in the Complete Accented Paradigm according to Zaliznyak:
aviation, aviation, aviation, aviation, aviation, aviation, aviation, aviation, aviation, aviation, aviation, aviation, aviation data, aviation, aviation, aviation, aviation, aviation, aviation, aviation, … - COMPASS
It helps, doesn't... - COMPASS in the Dictionary for solving and composing scanwords:
Southern... - COMPASS in the Dictionary for solving and composing scanwords:
Assistant... - COMPASS in the New Dictionary of Foreign Words:
(later Latin compasso measure) a device for orientation relative to the sides of the horizon, indicating the direction of the geographic (true) or magnetic meridian; The simplest compass is... - COMPASS in the Dictionary of Foreign Expressions:
[a device for orientation relative to the sides of the horizon, indicating the direction of the geographic (true) or magnetic meridian; The simplest compass is a magnetic one, in a housing... - COMPASS
air compass, astrocompass, hydrocompass, gyro-latitude compass, pel compass, pel compass, radio astro compass, radio compass, ... - AVIATION in the Russian Synonyms dictionary:
aeronautical... - COMPASS
m. 1) A device for orientation relative to the sides of the horizon, indicating the direction of the geographic or magnetic meridian. 2) transfer decomposition The one who determines... - AVIATION in the New Explanatory Dictionary of the Russian Language by Efremova:
adj. 1) Correlative in meaning. with noun: aviation, associated with it. 2) Characteristic of aviation, characteristic of ... - COMPASS in Lopatin’s Dictionary of the Russian Language:
compass, ... - AVIATION in Lopatin's Dictionary of the Russian Language.
- COMPASS in the Complete Spelling Dictionary of the Russian Language:
compass,... - AVIATION in the Complete Spelling Dictionary of the Russian Language.
- COMPASS in the Spelling Dictionary:
compass, ... - AVIATION in the Spelling Dictionary.
- COMPASS in Ozhegov’s Dictionary of the Russian Language:
a device for determining the cardinal points (sides of the horizon) Magnetic card (with a magnetized arrow, always pointing to ... - COMPASS in Dahl's Dictionary:
husband. , German , Belomorskoe, uterus, magnetic needle on a pin, with a paper card on which the cardinal points or 32 are indicated... - COMPASS in the Modern Explanatory Dictionary, TSB:
(German: Kompass), a device indicating the direction of the geographic or magnetic meridian; serves for orientation relative to the sides of the horizon. There are magnetic, mechanical (gyrocompass), radio compass... - COMPASS
(compass obsolete), compass, m. (Italian compasso) (physical). A physical device for recognizing cardinal directions, consisting of a magnetized needle that always points to ... - AVIATION in Ushakov’s Explanatory Dictionary of the Russian Language:
aviation, aviation. Adj. to aviation. Aviation... - COMPASS
compass m. 1) A device for orientation relative to the sides of the horizon, indicating the direction of the geographic or magnetic meridian. 2) transfer decomposition The one who … - AVIATION in Ephraim's Explanatory Dictionary:
aviation adj. 1) Correlative in meaning. with noun: aviation, associated with it. 2) Characteristic of aviation, characteristic of ... - COMPASS
- AVIATION in the New Dictionary of the Russian Language by Efremova:
adj. 1. ratio with noun aviation, associated with it 2. Characteristic of aviation, characteristic of ... - COMPASS
m. 1. A device for orientation relative to the sides of the horizon, indicating the direction of the geographic or magnetic meridian. 2. transfer decomposition The one who determines... - AVIATION in the Large Modern Explanatory Dictionary of the Russian Language:
adj. 1. ratio with noun aviation I, associated with it 2. Characteristic of aviation [aviation I], characteristic of ... - COMPASS in the Large Modern Explanatory Dictionary of the Russian Language:
m. Constellation of the Southern ... - LIFTING AIRCRAFT ENGINE
aircraft engine, a gas turbine engine, usually of a somewhat simplified design, that develops vertical thrust in a vertical take-off and landing aircraft. P. a. ... - in the Great Soviet Encyclopedia, TSB:
Aviation Institute named after. Sergo Ordzhonikidze (MAI), one of the largest educational and research centers in the field of aircraft manufacturing in the USSR. Founded in… - in the Great Soviet Encyclopedia, TSB:
Aviation Institute, trains engineers for the aviation, instrument-making, radio-electronic and mechanical engineering industries. Founded in 1932 on the basis of the aerodynamic department of Kazan University. ... - AIRCRAFT ALTIMETER in the Great Soviet Encyclopedia, TSB:
aviation, a device for measuring the altitude of an aircraft above the ground. There are barometric altimeters and radio altimeters. The principle of operation of barometric V. ... - DMB (FILM) in the Wiki Quotation Book.
-
k B - Soviet heavy-caliber aviation machine gun of 12.7 caliber ... - MACHINE GUN in The Illustrated Encyclopedia of Weapons:
AVIATION FEDOROV-DEGTYAREV, PROTO SAMPLE 1925 - Soviet built-in aviation machine gun of caliber 6, 5 ...
The magnetic compass in an airplane determines and maintains the heading of the flight direction. The aircraft heading is the angle between the real longitudinal direction and the aircraft axis along the meridian. It is customary to count the course from the northern direction of the meridian.
From the meridian, the angle is measured clockwise to the longitudinal axis of the aircraft. As we know, the course is possibly magnetic, compass and genuine.
The operating principle of each compass is based on the action of a magnetic needle, which is installed in the plane of the magnetic meridian in the north direction. After determining the magnetic meridian, the angle to the longitudinal axis of the aircraft is measured using a compass - this is the magnetic course. It must be emphasized that modern compasses installed in the cockpit are structurally different from field compasses.
In the construction of aviation compasses, materials are used that do not exhibit strong magnetic or diamagnetic properties. The main structural parts of an aircraft compass are: bracket, heading line, deviation device, card, bowler.
A cauldron is a vessel made of aluminum or copper and hermetically sealed with a glass lid. The inside of the pot is filled with liquid, in most cases it is naphtha or ethyl alcohol. Replacing or adding fluid significantly impairs the operation of the device and can lead to complete unusability.
The liquid helps as a calmer and dampens the vibrations of the cartridge, in addition, it reduces the pressure of the stud on the firebox.
In the middle of the pot there is a column on which the card is attached. A card is a complex of connected magnets, which are directed one to one with the same charged pole. As a rule, aviation compass cards are made up of two horizontal and two vertical magnets.
The magnets must be positioned with a high degree of accuracy, because the slightest shift can lead to deviations from the original values. The upper pairs of magnets have a much larger magnetic moment than the lower ones, in a ratio of 15 CGSm to 12 CGSm. As a result, the total moment should be no lower than 54-56 CGSm. The level of quality of the compass depends on the correct selection of their sizes and magnets.
At the end of the map there is an arrow, which indicates the side of the horizon; it helps to navigate the flight map. The non-specialized magnetic system is calculated for 200 hours of engine operation. A course line is applied to the bowler, which is used as an index when calculating the course.
The airplane compass bowl is filled with liquid; when the temperature changes, its quantity changes, which can lead to an error in the instrument’s readings. In order to avoid a similar situation, a compensation chamber is installed.
This design is used in all modern aircraft compasses. There are differences, they appear mostly in the aggregate of depreciation or the shape of the card. In addition, lighting devices are used to operate in night mode.
The practical use of a compass on an airplane suggests that its use is different for a pilot and a navigator. The pilot uses this device to select the right direction of flight. It is used to identify the accuracy of deviations and analyze the flight from the course.
As for the navigator, he uses a compass to quickly calculate the flight map and to analyze the course. The navigator's compass is usually considered to be the main compass on board an aircraft. Therefore, there are two types of magnetic aviation compasses that are installed on the board of an aircraft - the main one and the travel one.
Aircraft magnetic compass deviation
Even at the dawn of aircraft construction, all aircraft, without exception, were equipped with magnetic compasses, which performed an excellent job of determining the magnetic heading of the aircraft. However, with the upcoming development of multi-engine units with a large part of electronics, serious problems with the operation of compasses have appeared. All electromagnetic vibrations emanating from the second devices significantly affected the accuracy and performance of the instrument.
In some cases, compass readings could differ from the original ones by a dozen degrees, and this is quite a lot to determine the correct direction of flight. During the flight, all compasses experience accelerating and magnetic effects, which lead to deviation.
Magnetic deviation. The totality of each compass takes effect from different magnetic fields of both the Soil itself and other sources of magnetism specifically on board the aircraft. This could be radio systems, electrical wiring and its fields, and the metallic mass of the structure itself.
Therefore, compasses on board an airplane have errors in their readings, which are commonly called magnetic deviation.
This deviation parameter can be calculated at the experimental level; in addition, three subcategories of deviation are distinguished, in particular constant, quarter and semicircular.
The constant magnetic deviation on board the aircraft is caused by the inaccuracy of the compass itself. It is characterized by dependence on the magnetic course itself.
The semicircular magnetic deviation in the deviation of the compass reading is possibly caused by the so-called hard iron, which has a permanent magnetic charge. In addition, readings are affected by more permanent sources, such as wiring elements and electrical appliances. They have a constant force and direction of action on the compass.
There is also such a thing as inertial deviation, which appears due to bumpiness, speed transformation, turn, all this forms forces that affect the readings of the magnetic compass on board the aircraft. All this significantly complicates the work with calculations and the device for correct direction.
Nevertheless, when manufacturing the airplanes and compasses themselves, the designers take into account all deviations and these influences. To reduce third-party actions on the accuracy of the compass readings, aggregates are used, which can significantly reduce all of the above actions on the accuracy of the readings.
Review of the compass and men and airplanes
