If the RUDDER BOOST annunciator is illuminated,
yaw damper and rudder boost will not engage.
(9) Radio altimeter - Check valid on EADI.
To perform the following checks, the air data
computer must be valid and less than 60 knots, and
the radio altimeter must be valid and less than 50
feet. These conditions must be satisfied to avoid
tripping the autopilot servo monitors while
overpowering the autopilot servos.
(10) Control wheel - Move to mid-travel.
(11) AP ENGAGE switch-indicator (autopilot
controller) - Depress to engage
autopilot and yaw damper. Check that
AP ENGAGE and YD
switch-indicators on the autopilot
controller and the remote annunciators
on the instrument panel are illuminated.
Autopilot elevator trim follow-up - Check as
(1) Control wheel - Hold aft of mid-travel.
(2) Trim wheel (autopilot controller) -
approximately 3 seconds.
controller) - Check illuminated after 6 to