BendixKing KXP 756 - Manual (Page 18)

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indicated in nautical miles on the
range/groundspeed/time-to-station
indicator. The distance is measured
on a slant from the aircraft to the
ground and is commonly referred to
as slant-range distance. Slant-range
distance should not be confused with
actual ground distance. The differ-
ence between slant-range distance
and ground distance is smallest at a
low altitude and long range. These
distances may differ considerably
when in close proximity to a TACAN
or VORTAC ground station. However,
if the range is three times the altitude
or greater, the error is negligible. To
obtain accurate ground speed and
time-to-station, the aircraft must be on
a direct course to or from a TACAN or
VORTAC ground station.
Note: It is recommended that the
power to the KTU 709 TACAN system
be turned on only after engine start-
up as this procedure increases the
reliability of the solid state circuitry.
The KDI 572/573/574 indicators
display range to the nearest 0.1
nautical mile from 0 to 99.9 nautical
miles and to the nearest 1 nautical
mile from 100 to 389 nautical miles.
Groundspeed is displayed to the
nearest knot from 0 to 999 knots.
Time-to-station is displayed to the
nearest minute from 0 to 99 minutes,
the display also will indicate 99
minutes for any computed time-to-
station greater than 99 minutes. The
indicators will display “RNV” when the
displayed range, groundspeed and
time-to-station are derived from an
area navigation system. The
indicators will display “dashes” while
in search or if power is turned on or
momentarily interrupted while in the
frequency Hold mode, indicating loss
of the DME holding frequency. Normal
operation is re-established by placing
the KDI 572/574 function switch in the
N1 (NAV 1) or N2 (NAV 2) position. A
“1” (one) is displayed when N1 or a “2”
(two) is displayed when N2 has been
selected as the channeling source. In
the Hold mode either a “1H” or “H2” is
displayed to indicate the channeling
source being held.
The KDI 573 Slave Indicator
provides a display identical to the
display on the KDI 572/574 Master
Indicator. An automatic dimming
function is designed into both
indicators to adjust the brightness of
the display to compensate for changes
in the ambient light level.
The KDI 572 Master Indicator
function selector switch serves as the
Power ON-OFF control for the system
as well as slecting the TACAN
channeling source N1 (NAV 1), Hold
(NAV 1 or NAV 2) and N2 (NAV 2).
The KDI 574 requires a external panel
mounted switch to provide ON-OFF
and NAV 1, HOLD, NAV 2 Switching.
In hold (H1 or H2) The KDI
572/574 will uncouple the frequency
selector control from the TACAN and
allow a new navigation frequency to
be selected without channeling the
KTU 709, until the N1 (NAV 1) or N2
(NAV 2) function is again selected on
the KDI 572/574. This feature may be
used to advantage during an approach
where both NAV receivers are tuned
to the ILS frequency. If there is no
corresponding DME channel on the
ILS frequency, the TACAN may be
channeled to a nearby VORTAC
station before the approach is begun
and then placed in Hold position
where it will remain giving useful
distance information up to the time of
loss of signal.
The KTU 709 TACAN will not
output TACAN bearing composite
when its designated tuning source
(either NAV 1 or NAV 2) is deselected
or when a frequency HOLD is
attempted (either NAV 1 or NAV 2).
This feature provides better pilot