3-25
The DIRECTION OF PRECESSION in a gyro is always 90º from the direction of the applied
force.
A GYRO ERECTION SYSTEM must be capable of sensing the difference between the present
rotor position and the desired rotor position, and must apply forces that will cause the gyro to precess
toward the desired position. The mercury erection system discussed in this chapter is only one of several
possible types of gyro erection systems.
