Beechcraft C-12C Operator And Technical Reference Manual page 273

(4) Knots/Minutes Display. Digital display of
time-to-station in minutes or groundspeed of aircraft in
knots. This information is accurate only if the aircraft
is flying directly toward the ground station.
(5) DIM Control. Controls intensity of digital
readouts.
d. Normal Operation.
(1) Determining Slant Range Distance to
Station.
1. VOR control panel – Tune required
station.
2. DME SEL switch – VOR-1 or VOR-2.
3. DME
distance in nautical miles.
(2) Determining Groundspeed And Time-To-
Station.
1. VOR control panel – Tune required
station.
2. DME SEL switch – VOR-1 or VOR-2.
3. DME indicator control switch – KTS.
4. DME knots/minutes display – Read
aircraft's groundspeed in knots and
time-to-station in minutes.
3A-26. GLOBAL
(KLN 90B).
For information on the Global Positioning
System, refer to Chapter 3, Paragraph 3-7.
3A-27. AUTOPILOT SYSTEM (AP-106).
a. Description.
integral part of the flight control system. The autopilot
and flight director have a common computer system.
When the autopilot is engaged, the flight control
system controls the aircraft and the pilot monitors the
flight path by observing the information displayed on
the pilot's horizon reference indicator, the pilot's
horizontal situation indicator, and the flight director
system indicators. The autopilot system can maintain
a pre-selected attitude, maintain a barometric altitude,
maintain an indicated airspeed, capture and maintain a
desired heading, capture and maintain a pre-selected
radio course, and capture and maintain an ILS
MILES indicator –
POSITIONING SYSTEM
The autopilot system is an
approach to published minimums. The autopilot/flight
director commands are selected by the autopilot mode
selector panel located on the pedestal extension. Roll
rate and pitch commands can be given to the system
through the autopilot pitch-turn panel, located on the
pedestal extension.
autopilot is indicated on the autopilot/flight director
annunciator, located on the instrument panel directly
above the pilot's horizon reference indicator.
autopilot control switches are also provided on each
control wheel.
CWS, pitch synchronize and control wheel steering,
and the other is placarded DISC TRIM/AP YD,
disconnect trim/autopilot yaw damp.
system is protected by the 10-ampere AP PWR circuit
breaker located on the overhead circuit breaker panel.
b. Autopilot Mode Selector.
flight director commands are selected by the autopilot
Read
mode selector. Selection is accomplished by pressing
the face of the appropriate push-on/push-off switch.
The lateral modes are HDG, NAV, APPR, and B/C.
When not in a lateral mode the flight director command
bars are biased out of view. The vertical modes are
ALT, IAS and pitch, and are all hold modes.
vertical mode is not selected, the pitch hold mode is
automatically operational. Selection of a mode causes
the legend of that push-button switch to illuminate.
The self-test switch on the lower right of the autopilot
control panel acts as a lamp test when pressed. For
operation at night, overall illumination of the autopilot
mode selector and switches is adjusted by the console
light control.
c. Controls and Functions, Mode Selector.
Refer to Figure 3A-19.
(1) HDG Switch/Indicator. Engages heading
mode. Commands aircraft to acquire the heading
indicated by heading marker on pilot's HSI.
(2) NAV
navigation mode.
commands intercept and track VOR radial selected on
pilot's HSI.
(3) APPR
approach mode. Commands aircraft to intercept and
track ILS inbound course.
(4) B
backcourse mode.
backcourse ILS.
(5) AUTO PILOT TRIM TEST Indicator.
Illuminates when in test position.
TM 1-1510-218-10
The operating status of the
One is placarded PITCH SYNC &
The autopilot/
Switch/Indicator.
VOR-1 or VOR-2
Switch/Indicator.
C Switch/Indicator.
Commands aircraft to intercept
Two
The autopilot
If a
Engages
selected
Engages
Engages
3A-31