3.7. GYROSCOPIC PRECESSION
The result of applying force against a
rotating body occurs 90 in the direction of
rotation from where the force is applied. This
effect is called gyroscopic precession and it is
illustrated in figure 3.5. For example, if a
downward force is applied at 9 o'clock, as in the
figure, the result appears at 6 o'clock as shown.
This will make the 12 o'clock position in the
figure tilt up an equal amount in the opposite
direction.
Figure 3.6 illustrates the offset control
linkage needed in a helicopter to enable the pilot
to tilt the main rotor disc in the direction he
wants to go. If such linkage were not used the
pilot would have to move the cyclic stick 90
out of phase or to the right of the direction
desired. The offset control linkage is attached to
a lever extending 90 in the direction of rotation
Figure 3.4. Tail Rotor Thrust to Compensate
from the main rotor blade.
for Torque.
Figure 3.5. Gyroscopic Precession.
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