Specifications

SECTION III
MODEL 560 INSTRUMENTATION AND AVIONICS
The IND-42C power switch (PWR) controls power to the indicator and to the DME-442
receiver-transmitter. The mode selector switch (SEL) is a nonlatching pushbutton switch which selects the
information to be displayed in the alphanumeric (right) digital display. When initially powered up, the
alphanumeric display will show ID (DME station identifier). Pressing the SEL switch will sequentially select
KT (knots), MIN (minutes-to-station), and ID. An NM (nautical miles) display is continually shown on the
numeric (left) digital display. The annunciators 1, 2, NM, HLD (hold), KT, MIN, and ID will be present when
the respective selection is made in order to identify the digital data presented and the source of the data.
Distance Measuring Equipment (DME) groundspeed or time to station readouts are only accurate
when the airplane is proceeding directly to or from the selected station. Since it is slant range that is
computed, groundspeed or time to station accuracy increases with distance from the station. The readouts
can be considered reasonably close to actual speed when distance from the station in miles is equal to or
greater than the airplane altitude in thousands of feet.
If the pilot desires to retune the CTL-32 NAV control to which the DME indicator is selected, but to
retain the DME readout of the present station, HLD is selected on the respective NAV control before the set
is retuned. The DME will hold on the previously tuned frequency and HLD will be annunciated on the
IND-42C indicator. An amber "H" will also be annunciated to the left of the distance display on the EHSI
presentation to indicate the DME frequency is being held.
The DME-442 system is self-tested by pressing the TEST button on a CTL-32 NAV receiver. Upon
initiation of self-test, all display segments and annunciators on the IND-42C indicator will illuminate for a
lamp test. If NM and ID were selected for display, the numeric display will show 100 NM. If KT was
selected for display, the alphanumeric display will show 100 KT. If MIN was selected for display, 60 MIN
will be displayed. At the completion of the test routine, AOK will appear in the alphanumeric display if no
faults were detected. AOK will also be heard over the DME aural output. The IND-442 displays will then
return to normal. If a fault is detected, the word DIAG and a self-test fault code will be displayed. A list of
fault codes is found in the Component Maintenance Manual and a partial list in the Collins Pro Line II Pilot's
Guide 523-0773070-001117, dated January 5, 1987, or later revision.
NOTE
The self-test routine takes approximately ten seconds to complete. For that reason, it
should not be attempted during a critical phase of flight.
RADIO ALTIMETER
HONEYWELL AA300
The Honeywell AA300 radio altimeter displays the absolute altitude in a digital readout on each
primary flight display (PFD). The radio altimeter system is a high resolution, short pulse system which
provides continuous operation in a wide variety of conditions. It operates on a frequency of 4300 MHz.
Figure 3-30. IND-42C Indicator
I 56OMB-01 Configuration AA 3-65