i. Disengaging the Autopilot. The autopilot is
normally disengaged by momentarily pressing the
control wheel AP DISC switch. The autopilot may,
however, be disengaged by any of the following:
1. Actuation of the control wheel AP DISC
button. Disengagement is confirmed by
five flashes of the AP ENG annunciator.
2. Pressing the respective vertical gyro
FAST ERECT button.
INCREASE / DECREASE switch.
Disengagement is confirmed by the AP
ENG annunciator flashing five times and
illumination of the GA and YD ENG
5. Pulling the autopilot AP POWER circuit
6. Pressing the autopilot AP ENGAGE push
7. Transferring between pilot and copilot
Any of the following malfunctions will cause the
autopilot to automatically disengage.
8. Vertical gyro failure.
9. Directional gyro failure.
10. Autopilot power or circuit failure.
11. Torque limiter failure.
Disengaging under any of the last four conditions
will illuminate the AP DISC annunciator and the
flashing MASTER WARNING light. Pressing the
control wheel AP DISC switch will extinguish the AP
j. Elevator TRIM Annunciators. The elevator
trim annunciator indicates UP or DN when a sustained
signal is being applied to the elevator servo. The
annunciator should not be illuminated when engaging
Only the TCS button on the side that has
changing the autopilot without canceling
the other pilots GA mode.
k. Touch Control Steering (TCS). The TCS
push button located on the control wheel allows the
pilot to manually change aircraft attitude, altitude,
vertical speed, and/or airspeed without disengaging
the autopilot. After completing the manual maneuver,
the TCS push button is released, and the autopilot will
automatically resynchronize to the vertical mode. For
example, with IAS mode selected, the pilot may press
the TCS push button and manually change airspeed.
Once trimmed at the new airspeed, the TCS push
button is released and the autopilot will hold this
airspeed. If a large pitch attitude change is made, the
pilot should trim the aircraft normally before releasing
the TCS button while in the ALT hold mode.
3C-25. FLIGHT MANAGEMENT SYSTEM NO. 1
(1) System Overview. The FMS-800 flight
management system provides global autonomous
guidance using GPS navigation. This FMS guidance
may be used to fly published airways, direct routing,
TACAN emulation procedures, and published non-
precision or autonomous GPS approaches, as well as
various mission patterns.
The FMS-800 permits pre-flight loading of 40
complete mission plans using a data cartridge. It also
permits the crew to generate or modify mission plans
on the aircraft, using a global International Civil
Aviation Organization (ICAO) data base of waypoints
and automatic flight plan calculations.
The FMS-800 also provides simplified crew
control of the communication radios.
The C-12 installation uses a single Control
Display Unit (CDU). Any references to
"designated pilot" in this manual refer to
(2) System Architecture. Figure 3C-22
shows a simplified diagram of the FMS-800 system.
The CDU provides access to all system functions for a
single crewmember. It also provides user interface
between the FMS-800 and MIL-STD -1553B and non-
1553B aircraft systems.