Systems Guide

Aerosoft
Twin Otter E
XTENDED
Systems
Vol
2
2-1-14
19 November 2013
COLLINS AP-106 AUTOPILOT
The Twin Otter Extended comes with a Collins AP-106 autopilot and FD-112V Flight Director. The ADI contains
Flight Director Bars which indicates the required flight path to obtain the desired autopilot functions. When
the Autopilot is engaged but no lateral mode selected, also called "Manual" mode. In this mode the Left/Right
acting knob on the center of the Yoke will set the desired bank angle. When the Autopilot is engaged but no
vertical mode selected, this called "Manual" mode. In this mode the thumbwheel in the center of the
Left/Right knob on the center of the Yoke will set desired pitch.
The following lateral modes can be set on the AP-106 autopilot panel:
• HDG: Sets desired heading to follow.
• NAV: Sets the autopilot to follow either the radial of a VOR station or will track the localizer of an ILS.
The VOR or ILS frequency must be tuned on the GPS NAV radio and the radial /front course must be
set on the HSI.
On the GPS pressing the CDI button you can selects whether NAV should follow a tuned VOR station
or a GPS flight plan. VLOC means that the AP will follow a VOR or Localizer, and GPS means that the
AP will follow the flight plan loaded in the GPS. The GPS will indicate what course the HSI should be
set to whenever the GPS flight plan changes to the next waypoint. "NAV ARM" and "NAV CAP" lights
will indicate whether the AP has armed or has captured the desired radial or localizer.
By pressing the CDI button you can select whether NAV should follow a tuned VOR station or a GPS
flightplan.
• VLOC/GPS: VLOC means that the AP will follow a VOR or Localizer and GPS means that the AP will
follow the flight plan loaded in the GPS. The GPS will indicate what course the HSI should be set to
whenever the GPS flight plan changes to the next waypoint. "NAV ARM" and "NAV CAP" lights will
indicate whether the AP has armed or has captured the desired radial or localizer.
• APPR: Approach mode will arm and track both localizer and glideslope of an ILS once they are
captured. "NAV ARM" and "NAV CAP" as well as "GS ARM" and "GS CAP" lights will indicate whether
the AP has armed or has captured the desired localizer and glideslope.
• B/C: Will make the AP follow the back course of a localizer.
The following vertical modes can be selected on the AP-106 autopilot panel:
• ALT: Will hold the altitude present when the ALT button was pressed.
• IAS: Uses pitch to hold the indicated airspeed present when the IAS button was pressed: Increasing
power will initiate or increase rate of climb. Decreasing power will initiate or increase rate of descent.
IAS mode may therefore be used for both climb and descent.
The "TRIM IN MOTION" light will lit whenever the elevator trim is altered by the AP. There are also two lights
"TRIM UP" and "TRIM DN" on the main AP panel.
FD-112V FLIGHT DIRECTOR
The Flight director will indicate the computed commands from the autopilot through two bars on the ADI.
The vertical bar indicate required roll in order to obtain the selected lateral mode. The horizontal bar will
indicate required pitch to obtain the selected vertical mode. The FD turns on if either the autopilot has been
engaged or a FD mode has been selected (HDG,NAV, B/C,APPR,ALT or IAS).
Basically the FD bars will give the pilot cues on how to fly the aircraft the way the AP would have done in order
to get to the set lateral and vertical mode. If the vertical bar is displaced to the left, it means the pilot should