Autopilot Mode (Ap); Attitude Reference Mode Of Operation - Honeywell KFC 150 Pilot's Manual

Attitude Reference
Mode Of Operation
The system will be in the basic attitude
reference or "gyro' mode with engine(s) run-
ning and aircraft power on, but no modes
selected (annunciator panel blank). Aircraft
heading is shown on the KG 107 and pitch
and roll attitude on the KG 258 Horizon
Reference Indicator. (When the optional KI
525A PNI is installed in place of a KG 107,
aircraft heading will be shown
on
the KI
525A.)
Attitude Gyro Operation Note: When
shutting down the aircraft for short periods
of time, make sure the Attitude Gyro has
completely spun down before starting oper-
ations again. Gyro spin down occurs when
the air supply is cut off to the gyro and usu-
ally takes about 10 minutes.
During Gyro spin down most gyros
have a tendency to "tilt" (precess) to one
side. If the air supply is reapplied to the
gyro while in this state, slow gyro erection
(leveling) will occur due to gyro inertia. If
aircraft operations are initiated before the
gyro is fully erected, there is a greater pos-
sibility that the gyro may tumble causing
loss of primary attitude information from the
Attitude Gyro.
CAUTION: Overpowering the Autopilot
in the pitch axis in flight for periods of three
AUTOPILOT (AP) MODE
NOTE: The autopilot cannot be engaged
and used after power has been applied to
the system until the system self-test has
been performed.
and roll) stabilization and automatic elevator
trim as well as automatic response to all
selected autopilot modes.
On initial engagement, with no other
autopilot modes selected on the KC 191,
the KAP 150 will maintain the existing air-
craft pitch attitude and fly the aircraft wings
level.
yaw damper system will significantly damp
out yaw oscillations and improve turn coor-
dination.
WARNING: Whenever the autopilot is disen-
gaged the AP legend will flash and an aural
tone will sound to alert the pilot.
The autopilot provides two-axis (pitch
The addition of an optional third axis
seconds or more will result in the autotrim
system operating in the direction to oppose
the pilot and will, therefore, cause an
increase in the pitch overpower forces, and
if Autopilot is disengaged, will result in a
pitch transient control force. Operation of
the Autopilot on the ground may cause the
autotrim to run because of backforce gener-
ated by elevator downsprings or pilot
induced forces.
NOTE: For system limitations refer to the
Flight Manual Supplement for your particu-
lar aircraft.
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