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
Disconnecting Autopilot. The autopilot may be
disconnected by any of the following actions:
1. Pressing the DISC TRIM/AP YD
switch to first detent. (Location:
outboard horn either control wheel.)
2. Placing the ENG-DIS switch to DIS
position. (Location: AP mode select
panel.) NOTE After assuming
manual control, fly the aircraft using
the same heading, course, and
attitude displays to monitor autopilot
operation prior to assuming manual
Emergency Procedures. The autopilot can be
disengaged by any of the following methods:
1. Press the AP/YD disconnect switch
(either control wheel).
2. Move the engage lever to DIS
position (either control wheel).
3. Engage the go-around mode (yaw
damper will remain on).
4. AP PWR and AFCS DIRECT circuit
breakers (overhead panel) Pull.
switch (overhead panel) -OFF.
6. Aircraft MASTER switch (overhead
conditions will cause the autopilot to disengage
1. Any interruption or failure of power.
2. Vertical gyro failure indication.
3. Flight control system power or
4. Autopilot trim failure.
3-28. INERTIAL NAVIGATION SYSTEM.
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 the ground-based data link
system, its own TACAN system, the aircraft encoding
altimeter, the true airspeed computer, and the gyro
magnetic 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, radio magnetic indicators,
and to mission equipment. The INS is independent of
aircraft maneuvers, weather conditions and terrain, and
in conjunction with other aircraft equipment permits
operations on instruments alone 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 lamp will light informing the
pilot of an eminent 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 or the Data Link system. Altitude
information is automatically inserted into the INS
computer by an encoding altimeter whenever the INS is
The Mode Selector Unit (MSU) (fig. 3-22) controls
system activation and selects operating modes.
The Control Display Unit (CDU) (fig. 3-23) provides
controls and indicators for entering data into the INS and
displaying navigation and system status information.
The INS system is protected by the 10-ampere
PRIME POWER and the 5-ampere HEATER 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 battery unit.