User manual

Page 55
Aircraft Operation Manual
Piper Cheyenne I, IA, II, IIXL
For ight simulation use only
CAUTION: When the autopilot is engaged, manual application of a force to the
pitch axis of the control wheel for a period of 3 seconds or more will result in the
autotrim system operating in the direction to create a force opposing the pilot.
This opposing mistrim force will continue to increase as long as the pilot applies a
force to the control wheel and will ultimately overpower the autopilot. If the au-
topilot is disengaged under these conditions, the pilot maybe required to exert
control forces in excess of 50 pounds to maintain the desired aircraft attitude
The pilot will have to maintain this control force while he manually retrims the
aircraft.
CAUTION: Prior to Autopilot engagement, the pilot should make sure the V-bar
commands are satised. This will prevent any rapid changes in the aircraft’s ight
path when the Autopilot is engaged.
HEADING SELECT/PRESELECT Mode (HDG SEL)
Select a desired heading by positioning the heading „bug” on the HSI. This is
done with the HDG knob on the HSI. Depress the HDG button on the Mode Con-
troller to activate the HDG SEL mode. „HDG SEL” will light on the Annunciator
Panel and a computed, visually displayed bank command is shown on the FCI.
Following this bank command, the aircraft will bank and roll out on the desired
preselected heading.
The Command V-bar on the FCI will deect in the direction of the shortest turn
to satisfy the commanded turn to the preselected heading. The aircraft may be
manually banked to realign the V-bar and satisfy the command or, if the Autopi-
lot is engaged, the aircraft will automatically bank, turn to, roll out and hold the
preselected heading. As the aircraft approaches the selected heading the V-bar
will command a rollout to wings level.
With the HDG SEL mode in operation, subsequent changes made in the heading
„bug” position on the HSI will immediately cause the V-bar on the FCI to call for
a turn to the new heading. The HDG SEL mode is cancelled when NAV or APPR
coupling occurs, or whenever the FD or HDG mode buttons are depressed.
CAUTION: An invalid heading source (compass ag in view) will automatically
disengage the autopilot. The autopilot may then be re-engaged, however, only
the vertical modes will be useable.