Electronic Attitude Direction Indicator (EADI) and the
Horizontal Situation Indicator (EHSI).
The MFD provides all of the internal diagnostics,
data processing, and hardware configuration to
provide the following display modes:
(1) HSI. Full compass rose (360) or HSI
ARC which includes course needles, a bearing needle,
heading bug, etc.
(2) Missed Approach Point. A centered 360
Missed Approach Point (MAP) or an expanded
compass rose segment (80). Both of these modes
include the current set of waypoints and course legs.
(3) ADI. Provides aircraft attitude pitch and
roll, lateral deviation, and vertical deviation.
(4) Primary Flight Display (PFD). ADI and
HSI combined on one display.
(5) Diagnostics. Provides Multi Functional
Display (MFD) status pages.
b. External Aircraft Controls.
(1) Reversionary Switch. The reversionary
switches are external push button switches allowing
the operator to place the EADI information on the
bottom display. The pilots switch is located on the
lower left portion of the dash panel under the Turn and
Slip Indicator. The copilots switch is located on the
lower right portion of the dash panel under the Vertical
Speed Indicator. The switch has two positions: normal
and reversionary. In the normal position the top
display is an EADI and the bottom display is an EHSI.
In the reversionary position the top display blanks and
the bottom display becomes an EADI.
(2) OBS / LEG Switch. The OBS / LEG
switch places the FMS 2 KLN 90B in either LEG or
OBS mode. The OBS / LEG switch is located on the
top center portion of the dash panel to the right of the
altitude select panel. While in LEG mode the KLN 90B
continuously updates the desired course in order to fly
a great circle route between the FROM and TO
waypoints. If the leg selection is made and FMS 2 is
selected as the primary navigation source, the digital
course label displays DTK. While in OBS mode the
pilots MFD control panel updates the course and
sends the manually selected course to the KLN 90B.
If the OBS selection is made and FMS 2 KLN 90B is
selected as the course source, the digital course label
displays CRS and reflects the pilots control panel
(3) EFIS #1 and EFIS #2 Power Switch. The
EFIS #1 / EFIS #2 power switch is a push-button
switch located on the lower left side of the dash panel
beneath the Turn and Slip Indicator. Power is applied
to the pilots display via EFIS #1 switch and power is
applied to the copilots display via EFIS #2 switch.
(4) DME Hold Switch. The DME hold switch
enables the DME hold feature of VOR 1. The DME
hold switch is located on the CTL -32 NAV Control
Head. The pilots MFD monitors the DME hold switch
and annunciates its position.
Switches. The COMPASS 1 switch is located on the
lower left side of the dash panel under the EFIS #1 /
EFIS #2 switch. The COMPASS 2 switch is located
on the lower right side of the dash panel under the
Vertical Speed Indicator. The compass switches
consist of a gyro FREE / SLAVE switch and an
INCREASE / DECREASE (slew) switch. Selecting
FREE on the FREE / SLAVE switch disengages the
gyro and allows manual slewing of the compass card
via the INCREASE / DECREASE Switch. When
FREE is selected, heading validity is ignored. The
COMPASS 1 switches control the pilot side compass
card and the COMPASS 2 switches control the copilot
side compass card. The MFD does not interface with
the slew Switches and only annunciates the state of
the FREE / SLAVE Switch.
c. Display Control Panel.
(1) MFD Control Panel. The MFD Control
Panel provides integrated display management via the
controls shown in Figure 3B-3. Unless otherwise
noted the pilots control panel drives the pilots
displays, and the copilots control panel drives the
copilots displays. The pilot can select PFD on the
display control panel when in the reversionary mode.
This makes the bottom display a PFD without some of
Whenever either display fails it is probable
that functions of that display will also fail.
Functions. Listed below are the controls found on the
Control Panel and their corresponding functions.
Refer to Figure 3B-3.