3-22 Change 3
The pilots and copilots symbol generators are the fo-
cal 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/
When engaged and coupled to the flight director com-
mands, 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 pilots or copilots respective control wheel
or the autopilot pitch wheel and turn knob located on the
3-16. ATTITUDE AND HEADING REFERENCE SYS-
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 sys-
tem, electronic flight instrument system, and weather ra-
dar antenna with pitch and roll information.
The inertial navigation system, when selected for dis-
play on the EFIS, also provides inputs to the flight control
The directional gyros, with the flux valve and compen-
sator, provide stabilized magnetic north referenced
heading information for use by the digital flight control
computer, electronic flight instrument system, INS, and
3-17. AIR DATA SYSTEM (ADZ-800).
The air data system consists of the digital air data
(BA-141), and the altitude preselector (AL-801).
The digital air data computer is a microprocessor-
based digital computer which accepts both analog and
digital inputs, performs digital computations, and sup-
plies both digital and analog outputs. It receives both pitot
and static pressure for computing standard air data func-
tions. Altitude preselect data is input from the altitude
preselector. Information from the digital air data comput-
er is sent to the pilots barometric altimeter indicator,
transponder, flight director/autopilot, INS, and GPS.
3-18. ELECTRONIC FLIGHT INSTRUMENT SYSTEM
a. Description. The electronic flight instrument sys-
tem consists of the pilots and copilots electronic attitude
director indicators (EADI) and electronic horizontal situa-
tion 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 at-
titude, heading, course orientation, flight path com-
mands, radio altitude, weather radar and lightning
sensor system presentations, and mode and source an-
b. Electronic Flight Instrument System (EFIS) Pre-
For this test to be valid, the AUTO PLT POWER
switch and the RADIO ALTIMETER switch must
1. TEST switch (display controller, fig. 3-8) - De-
press and hold.
2. Verify the following indications on the EADI:
a. Radio Altimeter - Slews to 100 +/-10 feet.
b. DH replaced with dashes.
c. Marker beacon symbology appears.
d. HDG and ATT annunciators appear.
e. ATT FAIL annunciator appears in the cen-
f. Pitch and roll command cue (artificial hori-
zon) - out of view.
g. Runway cue drops from center.
h. GS and localizer off flags (Red X) appear.
i. TEST will appear in the upper left corner
to indicate that the flight director mode se-
lector lamp is good.
3. Verify the following on the EHSI.
a. DTRK, NM, GSPD, and HDG replaces
b. HDG FAIL annunciator appears.
c. Course indicator and glidescope off flags
4. AP disconnect horn sounds after 5-7 seconds.
3-19. DISPLAY CONTROLLER (DC-811).
a. Description. The display controller (fig. 3-8), en-
ables each pilot to control formatting on his respective
EHSI and EADI, and to select the source of navigation,
attitude, and heading information.
b. Display Controller Controls, Indicators, and Func-
(1) Full/Map pushbutton selector switch. The
FULL/MAP pushbutton selector switch is a multiple func-
tion switch that allows selecting the format of the EHSI.