{"id":14480,"date":"2025-06-07T16:19:24","date_gmt":"2025-06-07T10:49:24","guid":{"rendered":"https:\/\/ibexaviation.com\/pilot-training\/?p=14480"},"modified":"2026-07-26T10:30:00","modified_gmt":"2026-07-26T05:00:00","slug":"gyroscopes","status":"publish","type":"post","link":"https:\/\/ibexaviation.com\/pilot-training\/gyroscopes\/","title":{"rendered":"Gyroscopic Theory"},"content":{"rendered":"<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-1.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<h2>Working Principle of Gyroscopes<\/h2>\n<p>Gyroscopes are used in aircraft to provide a stable reference for attitude, heading, and turn information.<br \/>\nThey are the operating principle behind instruments such as the attitude indicator, heading indicator, and turn coordinator. Gyroscopes help pilots maintain accurate control and orientation, even when outside visual references are unavailable.<\/p>\n<h3>Gyroscope &amp; Instruments<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-2.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Gyroscopes are used in a variety of flight instruments.<\/li>\n<li>Directional gyro indicator and gyro magnetic compass.<\/li>\n<li>Artificial horizon and turn &amp; slip indicator.<\/li>\n<li>Inertial navigation systems and inertial reference systems.<\/li>\n<li>Yaw dampers and autopilot.<\/li>\n<li>Stabilisation of radar scanners.<\/li>\n<\/ul>\n<h3>Gyroscopic Theory<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-3.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>A gyroscope has a spinning disc called the rotor which spins around its spin axis.<\/li>\n<li>Gyroscopes have two basic properties: rigidity and precession.<\/li>\n<li>A highly rigid gyroscope will have a low rate of precession and vice versa.<\/li>\n<li>A gyroscope with its spin axis horizontal to the Earth&#8217;s surface is called a horizontal gyro.<\/li>\n<li>A vertical gyro has its spin axis vertical to the Earth&#8217;s surface.<\/li>\n<\/ul>\n<h2>Rigidity and Precession of Gyroscope<\/h2>\n<p>Rigidity of a spinning gyroscope is its ability to maintain its axis in a fixed direction, providing a stable reference.<br \/>\nPrecession explains the effect on gyro when an external force is applied to a spinning gyroscope. The gyro responds by moving at right angles to the applied force due to precession.<\/p>\n<h3>Rigidity of Gyroscope<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-4.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Rigidity is also called gyroscopic inertia of a high-speed spinning rotor.<\/li>\n<li>The spin axis of a rotor maintains its direction relative to a point in space.<\/li>\n<li>This rule is valid only in the absence of any external force.<\/li>\n<li>The reference point in space could be a distant star.<\/li>\n<\/ul>\n<h3>Factors Affecting Rigidity<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-5.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Rigidity is affected by rotor mass, effective radius, and speed of rotation.<\/li>\n<li>Rigidity can be increased by increasing the mass or diameter of the rotor.<\/li>\n<li>Concentrating the rotor mass around its perimeter helps increase rigidity.<\/li>\n<li>Increasing the speed of rotation also increases rigidity.<\/li>\n<\/ul>\n<h3>Precession of Gyroscope<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-6.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Precession shifts the effect of an external force applied to the gyro.<\/li>\n<li>The effect of the external force is felt at right angles to the point of application.<\/li>\n<li>When an external force is applied to move the spin axis upwards,<\/li>\n<li>the spin axis will move to the right for a clockwise-spinning rotor.<\/li>\n<\/ul>\n<h3>Effect of Force on Precession of Gyroscope<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-7.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>When an external force is applied to change the spin axis of a gyro,<\/li>\n<li>the gyro resists the change caused by the external force.<\/li>\n<li>The spin axis moves 90\u00b0 from the direction of the applied force.<\/li>\n<li>The movement is in the direction of rotation of the rotor.<\/li>\n<\/ul>\n<h3>Rate of Precession<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-8.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>The rate of precession is directly proportional to the applied torque.<\/li>\n<li>The rate of precession is inversely proportional to the rotor mass and speed of rotation.<\/li>\n<li>These characteristics help maintain the property of rigidity.<\/li>\n<li><strong>Rate of Precession = Torque Applied \u00f7 (Rotor RPM \u00d7 Moment of Inertia)<\/strong><\/li>\n<li>A lightweight gyro rotating at lower speeds will have a higher rate of precession.<\/li>\n<li>A heavier gyro rotating at higher speeds will be more rigid and precess less.<\/li>\n<\/ul>\n<h2>Gimbal System in a Gyroscopic Assembly<\/h2>\n<p>Gimbals in a gyro assembly allow the gyroscope to remain free to tilt and rotate in different directions while keeping its spin axis stable in space. They isolate the gyro from aircraft movements so it can provide an accurate, independent reference for attitude or heading.<\/p>\n<h3>Single Gimbal System<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-9.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>The gyro is mounted in a ring-type suspension system called gimbals.<\/li>\n<li>Gimbals provide freedom of movement to the gyro.<\/li>\n<li>A single gimbal system provides the gyro with one degree of freedom.<\/li>\n<li>If this degree of freedom is aligned with the longitudinal axis,<\/li>\n<li>the spin axis will not be disturbed by aircraft pitch up or down.<\/li>\n<li>The spin axis will not be disturbed by aircraft banking left or right.<\/li>\n<li>Yawing movement of the aircraft will disturb the spin axis.<\/li>\n<li>A single gimbal system does not provide freedom to correct yaw.<\/li>\n<\/ul>\n<h3>Two Gimbal System<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-10.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>In a two-gimbal system, the inner gimbal is mounted on the outer gimbal.<\/li>\n<li>The outer gimbal is mounted onto the aircraft frame.<\/li>\n<li>A two-gimbal system provides the gyro with full freedom to move in any direction.<\/li>\n<li>The gyro can maintain its spin axis at a fixed point in space along all three axes.<\/li>\n<li>The spin axis remains undisturbed during pitch, roll, and yaw movements.<\/li>\n<\/ul>\n<h3>Function of Gyroscopes<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-11.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Gyroscopes can be classified based on their functions.<\/li>\n<li>Displacement gyros measure bank, heading, or pitch angles.<\/li>\n<li>Space gyros are unrestrained and free to wander.<\/li>\n<li>Tied gyros are returned to their original orientation by an external force.<\/li>\n<li>Earth gyros maintain their orientation relative to the Earth&#8217;s surface using gravity.<\/li>\n<li>Rate gyros measure the rate of change, such as the rate of turn.<\/li>\n<\/ul>\n<h3>Displacement Gyros<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-12.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Displacement gyros have two degrees of freedom using a two-gimbal system.<\/li>\n<li>They allow aircraft to pitch, roll, and yaw without disturbing the spin axis.<\/li>\n<li>Space gyros are unrestrained and maintain orientation relative to a point in space.<\/li>\n<li>They require low real wander and are used in inertial navigation systems.<\/li>\n<li>Tied gyros have two degrees of freedom and their spin axis is tied to a datum.<\/li>\n<li>The datum may be the horizontal or vertical plane of the Earth.<\/li>\n<li>Earth gyros are tied to the Earth&#8217;s surface by gravity.<\/li>\n<li>Directional gyro indicators use earth gyros.<\/li>\n<\/ul>\n<h3>Rate Gyros<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-13.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Rate gyros have a single-gimbal system with one degree of freedom.<\/li>\n<li>Turn indicators use rate gyros.<\/li>\n<\/ul>\n<h2>Power Sources of Gyroscopes <\/h2>\n<p>Gyroscopes are classified mainly based on power source and functionality. Based on Power source they are called air-driven or electrically-driven gyroscopes. Based on functions they are called Displacement or Rate Gyroscopes<\/p>\n<h3>Air-Driven Gyros<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-14.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Air-driven gyros use pneumatic power or air pressure to rotate the gyro.<\/li>\n<li>Pressurised air can be obtained from one of three sources:<\/li>\n<ul>\n<li>An engine-driven vacuum pump.<\/li>\n<li>Low-pressure air from the engine inlet manifold.<\/li>\n<li>A venturi mechanism mounted outside the aircraft.<\/li>\n<\/ul>\n<li>High-pressure air is accurately directed at the rotor to maintain a constant speed.<\/li>\n<li>Air-driven gyros are independent of electrical power.<\/li>\n<li>They continue to operate even during a total electrical failure.<\/li>\n<\/ul>\n<h3>Electric Powered Gyros<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/flight-instruments\/i14-gyroscopes-15.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Electric-powered gyros use an alternating current (AC) electric motor.<\/li>\n<li>Electric-powered gyros offer several advantages over air-driven gyros:<\/li>\n<ul>\n<li>Higher spin speeds increase rigidity.<\/li>\n<li>Constant rotor speed reduces real drift.<\/li>\n<li>The sealed gyro unit is protected from contamination and interference.<\/li>\n<li>Rapid achievement of operating rotor speed.<\/li>\n<li>Fast initialisation.<\/li>\n<\/ul>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Working Principle of Gyroscopes Gyroscopes are used in aircraft to provide a stable reference for attitude, heading, and turn information. They are the operating principle behind instruments such as the attitude indicator, heading indicator, and turn coordinator. Gyroscopes help pilots maintain accurate control and orientation, even when outside visual references are unavailable. Gyroscope &amp; Instruments Gyroscopes are used in a variety of flight instruments. Directional gyro indicator and gyro magnetic compass. Artificial horizon and turn &amp; slip indicator. Inertial navigation systems and inertial reference systems. Yaw dampers and autopilot. Stabilisation&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"disable_featured_image":false,"footnotes":""},"categories":[345],"tags":[],"class_list":["post-14480","post","type-post","status-publish","format-standard","hentry","category-cpl-atpl-flight-instruments"],"_links":{"self":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14480","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/comments?post=14480"}],"version-history":[{"count":1,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14480\/revisions"}],"predecessor-version":[{"id":16659,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14480\/revisions\/16659"}],"wp:attachment":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/media?parent=14480"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/categories?post=14480"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/tags?post=14480"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}