Compass aircraft
Compass aircraft

Compass aircraft. Magnetic compass aircraft.


Magnetic compass on the plane detects and stores the course direction of flight. The course of the aircraft - is the angle between the longitudinal axis of the aircraft and the actual direction of the meridian. It accepted to count rate from the northern direction of the meridian. By ticking the meridian angle clockwise to the longitudinal axis of the aircraft. As we know, the course can be magnetic, compass and true.

The principle of operation of each compass is based on the action of the magnetic needle, which is installed in the plane of the magnetic meridian in the north direction. After determining the magnetic meridian with the help of a compass, the angle to the longitudinal axis of the aircraft is measured - this is the magnetic course. It should be noted that the modern compasses installed in the cockpit of the aircraft are structurally different from the field ones. The design of aviation compasses uses materials that exhibit weak magnetic or diamagnetic properties. The main constructive parts of the compass are: bracket, course feature, deviation device, card, bowler.

Bowler - a vessel made of aluminum or copper, and a hermetically sealed cover glass. The inside of the pot filled with a liquid, usually a naphtha or ethyl alcohol. Replacing or refilling fluid significantly reduces the unit and can lead to the utter uselessness. The liquid serves as a damper and damps vibrations of the card, also reduces the pressure on the studs furnace.

Compass aircraft

In the middle of the pot is a column on which a card is attached. A kartushka is a complex of connected magnets, which are directed one to one by the same-named charged pole. In most cases, the charts of aviation compasses consist of two horizontal and two vertical magnets. Magnets should be located with a high degree of accuracy, since the slightest shift can lead to a deviation of the indicators from the true ones. The upper pairs of magnets have a significantly greater magnetic moment than the lower pairs, in the ratio 15 CGSm to 12 CGSm. As a result, the total moment must be no lower than 54-56 CGSm. From the correct selection of magnets and their size depends on the quality of the compass. At the end of the card is an arrow that points to the side of the horizon, it serves for orientation in the flight map. The total magnetic system is calculated for 200 hours of operation of the engines. Inside the bowler there is a heading feature, which is used as an index when counting the course.

Bowler compass plane filled with liquid, temperature changes, its volume change, this can lead to faulty readings. To avoid this situation, set compensation chamber.

This design is used in all modern aircraft compasses. There are differences, they are largely in the form of depreciation or compass card. Also for night mode are used lighting.

Practical use of the compass on the plane shows that its use for the navigator and pilot different. The pilot uses this instrument to select the correct direction of flight. It is used to analyze the loyalty of the flight and to identify deviations from the course. With regard to the co-driver, it uses the compass to quickly calculate flight maps and analysis of the course. Compass Navigator is considered to be the main on-board aircraft ship. Because of this are two types of magnetic compasses aircraft, which are installed on aircraft forest - and this is the main track.

Magnetic deviation of the aircraft

Even at the dawn of aircraft construction, all planes were equipped without exception with magnetic compasses, which coped well with the task set for determining the magnetic course of the apparatus. Nevertheless, with the further development of multi-engine aggregates with a large part of electronics, there were significant problems with the operation of compasses. All the electromagnetic oscillations emanating from other instruments significantly influenced the operation and accuracy of the instrument. In some cases, the compass readings could differ from the true ones by a dozen degrees, and this is very much to determine the correct direction of flight. All compasses during the flight experience accelerating and magnetic influences, which lead to deviation.

Magnetic deviation. Compass system each receives from the various effects of the magnetic fields of both the Earth and other sources of magnetism directly on board the aircraft. It can be radio, wiring, and its fields, and the steel weight of the structure itself. Because of this, the compasses on board the aircraft have errors in their statements, which are called the magnetic deviation.

This parameter deviations can be calculated from the experimental level, while there are three sub-categories of deviation, namely permanent, quarter and semi-circular.

Permanent magnetic deviation on board the aircraft caused by the inaccuracy of the installation of the compass. It is characterized by dependence of the magnetic heading.

Semi-circular magnetic deviation in the deviation of the compass can be caused by so-called hard iron, which has a permanent magnetic charge. Also readings affect more permanent sources such as electrical appliances and wiring components. They have a constant strength and direction of the impact on the compass.

Yet there is such a thing as inertia deviation, which occurs due to turbulence, change the speed, turns, all this creates the forces that influence the testimony of a magnetic compass on board. All this greatly complicates the product and the loyalty rating for directions.

Nevertheless, in the manufacture of compasses and the aircraft themselves, the designers take into account all these effects and deviations. To reduce third-party effects on the accuracy of the compass readings, systems are used that can significantly reduce all the above-mentioned effects on the accuracy of the readings. 



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