BMS F-16C/D 4.34, Flight Manual

Page: 143 / 234

T.O. BMS1F-16CM-1 BMS 4.34 Change 2.00
BMS 4.34 Dash 1
© Red Dog 2012-2019
Page: 143
1.14 AUTOPILOT OPERATION
The F-16 features an autopilot system interfaced through the two 3-position switches located at the
bottom of the MISC panel.
The left one labelled ROLL is a standard 3-position switch, the right one labelled PITCH is the master
autopilot switch. It is a magnetic switch held in place in
the up and down positions. It snaps back to the centre
position when the A/P is disengaged. The left switch is
operative only when the right switch is placed out of OFF.
The autopilot provides the following modes:
•
ROLL Attitude hold
•
Heading select (HDG SEL on ROLL switch)
•
Steering select (STRG SEL on ROLL switch)
•
Altitude hold (ALT HOLD on PITCH switch)
•
PITCH Attitude hold
There are two more important switches relevant to the autopilot system. The TRIM A/P DISC switch
on the MANUAL TRIM panel disengages the autopilot and the paddle switch on the sidestick overrides
the autopilot while depressed.
1.14.1. Altitude Hold
Placing the right PITCH switch to ALT HOLD commands the aircraft to maintain a constant altitude.
The reference altitude is the altitude the aircraft was at when the A/P switch was e/- 100 ft.
Vertical velocity above +2000 ft/min or below -2000 ft/min may prevent the correct altitude capture.
The FLCS limits the pitch command from 0.5 to 2.0G when PITCH ALT HOLD is engaged.
The AOA also plays an important role in altitude capture. It remains accurate only below 5° AOA.
Stick steering & Autopilot override
If the pilot moves the stick while the A/P is engaged the aircraft will respond to pilot input, although the
stick will feel slower than usual. Upon releasing the stick the autopilot will resume its previous settings.
For example if you were flying 15000 feet with ALT HOLD engaged and pulled the stick back climbing
slowly to 20000 feet, when you released the stick the aircraft would descend back to 15000 feet.
If you want the aircraft to remain at 20000 feet in this example you would need to depress the paddle
switch when leaving 15000 feet (overriding the A/P setting), climb slowly to 20000 feet and then
release the paddle switch. Upon releasing the paddle the A/P will take this new actual altitude as the
reference.
1.14.2. Attitude Hold (PITCH)
Placing the right PITCH switch to ATT HOLD mode commands the aircraft to maintain the current
pitch attitude. Angles above or below 60° in pitch will not be captured.
As in altitude mode stick steering is available and the pitch can be changed with stick input but there is
no need to hold in the paddle, the autopilot in ATT will capture a new pitch attitude whenever the stick
is moved.