TM 1-1510-224-10
The pilot's and copilot's symbol generators are
the focal point of information flow in the systems. The
symbol generator converts information to video and
deflection formats required by the EADI and EHSI
displays, and provides analog steering information to the
flight director/autopilot interfaces.
When engaged and coupled to the flight director
commands, the digital integrated flight control system
will control the aircraft using the same commands
displayed on the EADI. When engaged and not coupled
to the flight director commands, manual pitch and roll
commands may be inserted using the touch control
steering (TCS) switch on the pilot's or copilot's
respective control wheel or the autopilot pitch wheel and
turn knob located on the pedestal extension.
3-16. ATTITUDE AND HEADING REFERENCE
SYSTEM.
The attitude and heading reference system
consists of the vertical gyros (VG-14A), directional gyros
(C-14A), dual remote compensator (CS-412), flux valves
(FX-220), and the inertial navigation system (INS).
The vertical gyros provide the digital flight
control system, electronic flight instrument system, and
weather radar antenna with pitch and roll information.
The inertial navigation system, when selected
for display on the EFIS, also provides inputs to the flight
control computer.
The directional gyros, with the flux valve and
compensator,
provide
stabilized
magnetic
north
referenced heading information for use by the digital
flight control computer, electronic flight instrument
system, INS, and mission equipment.
3-17. AIR DATA SYSTEM (ADZ-800).
The air data system consists of the digital air
data computer (AZ-800), pilot's barometric altimeter (BA-
141), and the altitude preselector (AL-801).
The
digital
air
data
computer
is
a
microprocesser-based digital computer which accepts
both
analog
and
digital
inputs,
performs
digital
computations, and supplies both digital and analog
outputs. It receives both pitot and static pressure for
computing standard air data functions. Altitude preselect
data is input from the altitude preselector. Information
from the digital air data computer is sent to the pilot's
barometric
altimeter
indicator,
transponder,
flight
director/autopilot, INS, and GPS.
3-18. ELECTRONIC FLIGHT INSTRUMENT SYSTEM
(EFIS).
a.
Description.
The
electronic
flight
instrument system consists of the pilot's and copilot's
electronic attitude
director indicators (EADI) and electronic horizontal
situation indicators (EHSI) display units (ED-800),
symbol generators (SG-805), display controllers (DC-
811), and instrument remote controllers (RI-106S).
The EFIS electronic displays present pitch and
roll attitude, heading, course orientation, flight path
commands, radio altitude, weather radar and lightning
sensor system presentations, and mode and source
annunciations.
b.
Electronic
Flight
Instrument
System
(EFIS) Preflight Test.
NOTE
For this test to be valid, the AUTO
PLT POWER switch must be on and
the radio altimeter must be on.
1.
TEST switch (display controller, fig. 2-18)
- Depress and verify the following:
2.
EADI
a.
Radio altimeter - Stews to 100 ±10
feet.
b.
DH display replaced with dashes.
c.
Marker
beacon
-
All
three
annunciators will be in view.
d.
HDG and ATT annunciators appear.
e.
ATT FAIL annunciator appears.
f.
Pitch and roll command cue - Out of
view.
g.
Caution and warning flags - All will
be in view.
h.
FD FAIL will appear momentarily
and then be replaced in the left
center of the display by the word
TEST to indicate that flight director
mode selector lamp test is good.
3.
EHSI - DTRK, NM, GSPD, and HDG
displays replaced with dashes.
4.
AP disconnect horn sounds after 5-7
seconds.
Preflight test of the composite mode will cause
the same results as the above test, except the digital
heading readout will be replaced with a red FAIL
indication, and the expanded localizer scale and pointer
will be removed.
NOTE
A localizer frequency must be tuned
on both NAV receivers to annunciate
ILS comparator
monitor.
3-22
