TM 55-1510-220-10
4.
Heading switch (autopilot mode selector
control panel, fig. 3-20) Press.
Observe
that HDG light illuminates on
autopilot/flight director annunciator
panel.
5.
Back course switch (autopilot mode
selector control panel) Press. Observe
that NAV ARM lights illuminate
(autopilot/flight director annunciator
panel) indicating system is armed for
back localizer capture. Any previously
selected vertical mode will cancel.
6.
NAV CAP light will illuminate when
system has captured back localizer
course.
7.
Pitch control (autopilot/pitch turn panel)
Use to establish and maintain desired
rate of descent.
NOTE
The HDG mode should be used within
one mile of the runway due to the
large radio deviations encountered
when
flying
over
the
localizer
transmitter.
r.
Yaw Damper Operation.
(1)
The rudder channel of the autopilot may be
selected separately for yaw damping by depressing the YAW
DAMP switch on the pedestal. The switch face will
illuminate when the yaw damper is engaged.
(2)
To disengage the yaw damper, press the
disconnect button on the pilot's or copilot's control wheel to
the first detent or press the YAW DAMP switch on the
pedestal.
(3)
Refer to Emergency Procedures for other
means of disconnecting the yaw damper.
s.
Disconnecting Autopilot. The autopilot may be
disconnected by any of the following actions:
(1)
Pressing the DISC TRIM AP YD switch
(control wheels, fig. 2-30) to the first detent.
(2)
Placing the autopilot engage disengage switch
(autopilot mode selector control panel, fig. 3-20) to the DIS
position.
(3)
Refer to Emergency Procedures for other
means of disconnecting the autopilot.
NOTE
After assuming manual control, fly the
aircraft using the same heading,
course, and attitude displays used to
monitor autopilot operation prior to
assuming manual control.
3-29. INERTIAL NAVIGATION SYSTEM.
a.
Description. The Inertial Navigation System (INS)
is a self-contained navigation and attitude reference system.
It is aided by (but not dependent upon) data obtained from its
own TACAN system, the aircraft encoding altimeter, the true
airspeed computer, and the gyromagnetic compass system.
The position and attitude information computed by the INS is
supplied to the automatic flight control system, weather radar
system, horizontal situation indicator, and radio magnetic
indicators. In conjunction with other aircraft equipment, the
INS permits operation under Instrument Meteorological
Conditions (IMC). The INS provides a visual display of
present position data in Universal Transverse Mercator
(UTM) coordinates or conventional geographic (latitude-
longitude) coordinates during all phases of flight. When
approaching the point selected for a leg switch, an ALERT
light will illuminate informing the pilot of an imminent
automatic leg switch or the need to manually insert course
change data. The INS may be manually updated for precise
aircraft present position accuracy by flying over a reference
point of known coordinates. The INS may be updated
automatically by the TACAN system. Altitude information is
automatically inserted into the INS computer by an encoding
altimeter whenever the INS is operational.
The Control Display Unit (CDU) (fig. 3-25) provides
controls and indicators for entering data into the INS and
displaying navigation and system status information.
The Mode Selector Unit (MSU) (fig. 3-24) controls
system activation and selects operating modes.
The INS system is protected by the 10-ampere INS AC
POWER and the 5-ampere INS HTR AC POWER circuit
breakers on the mission AC/DC power cabinet, by the 5-
ampere INS CONTROL circuit breaker on the overhead
circuit breaker panel and by the 20-ampere circuit breaker on
the front of the INS battery unit.
3-45
