gyroscopic principles

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Gyroscopic PrinciplesRigidity in space

Gyroscope will remain in a fixed positionPrecession

When a force applied to gyro, it will respond as if force were applied 90* in direction of rotation

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Property of gyro (page 84)A) tendency of spinning gyro to remain fixed in space (the

gyro rotor will try to maintain its position in space even when mounting base is tilted and rotate(

B) right angle obstinacy (the effect of outside force to tilt or rotate the gyro will move at right angle to the direction of force in the direction of rotation

Behavior of vertical gyro (page 86)The gyro continuously being corrected to vertical position of

airplane this will make possible for pilot to know the actual attitude of his air plane

Attitude a) nose up nose down (pitch) b) wing level (roll)The output from gyro is used in a) Autopilot b) flight recorder c) radar antenna stabilization

d) flight director

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Gimbal Rings

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Gyro inside the indicator (page 87) it used inside the indicators mounted directly on the

instrument panelfigure 5-4gyro mounted with spin axis vertically and have free

movement in all axishorizon indicator coupled to the inner gimbals to show the

attitude of air planefigure 5-5 gyro mounted to the spin axis horizontallycompass indicator card attached to vertical gimbalsdisadvantage of this type need manual heading correction

use magnetic compass at level flight as reference) in commercial air craft we use large expensive gyro not

too far from the center of gravity and control remote indicators in flight instrument panel

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Gyro horizon indicator no. 1 and no. 2 (page 88-89)

Inner portion of this indicator is moveable sphereHeavy black line = horizon (separate the light

color upper half from dark lower half W with dot at center and horizon bar extending

from the sides represent the air plane this symbol is fixed position in front of sphere

figure 5-9 and figure 5-10 show the position of indicator with respect to air plane body

other figure show the position of indicator with respect to pilot

nose up –nose down can read angle on the sphere with the center of W

bank left and right can read from the top of indicator with respect to position lower triangle

Remote gyro horizon (page 90)Integrated instrument show in addition to attitude (roll pitch)Slip indicator (ball insert in curve tube filled with damping

fluid) to show the air plane if slipping or sliding to one side or other

Rate of turn indicator above slip indicator if the needle is directly out side one dot the air plane is turning at rate of 180 degree per minute in the direction indicated

Glide slope deviation indicator on the right sideSpeed error indicator on the left show the air plan travel

faster or slower the preselected speedDecision light s (on the upper right corner) show the preselected radio altitude above the run way has been reached or decent Flight director light (on left hand upper corner) show flight director turned onPush to test button (at lower left)

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Artificial Horizon with:-ILS-AOA-DH

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Red flag shows air or electric power is off line, thus

instrument is not reliable.

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Artificial Horizon

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Manual Caging

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Remote vertical gyro (page 91)Vertical gyro called because its spin axis is automatically maintain vertically by

gravity sensing roll and pitch erection systemsErection system :a system maintain spin axis verticallyWe have two erection system1. Roll axis erection system 2. pitch axis erection systemTorquer: frustrated motor used to erect the spin axisRoll Erection torquing is cut off when the bank angle exceeds about 6 degreeWe use isolated transformer in the output to lessen possible bad effect on the three

legged signalCommercial A/C never bank or pitch beyond

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Remote horizon system (page 92/93)

Remote gyro horizon system comprised off (vertical gyro, instrument modules(servo amplifier), horizon ind.)

Instrument module part of black boxPush to test (switch on the front face of indicator.) when

push the indicator. will show right wing down and nose up and the gyro warning flag appear

In parked airplane this test would indicate whether the trouble is probably in vertical gyro or servo amplifier or in horizon indicator

Remote directional gyro (page 94)

The spin axis of Directional gyro is maintained in horizontal position

Directional gyro is used in a remote reading compass

Rate gyro inside turn ind. (page 95)

Gyro inside panel mounted rate of turn ind. Used in autopilot The difference between rate gyro (free in one axis) and

normal gyro(free in all axis) is having freedom of movement in one axis

The gimbals is capable of moving around x-axis but its motion limited by the spring

Basic rate gyro basic (page 97)Instead of using aspiring to restrict the motion in one axis there

is a torsion bar

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Inclinometer – slip indicator

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Co-ordinated Turn

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Gimbals vs. strap down (page 99)

Gimbals system isolate the acceleration sensing devices from rotational motion of the air plane and maintain plate form parallel to the earth rotation

Gyro scopic which cause the gyro gimbals to rotate about the gyro output axis and generate output signal from the gyro pick off which represent the angular displacement of the Gimbals

Strap down system gyro and accelerometers are mounted to the body of the vehicle the total # of sensor in each system is twelve (6 gyro , 6 accelerometer

Advantage of strap down over Gimbals system is if any sensor in Gimbals system fail the entire system useless (navigation failure) but the strap down remains operational even after three gyro and three accelerometers have failed

MEMSMicro-electromechanical Sensor

RLG Ring Laser Gyro

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DC-9 777

EADI