navigation cross-reference. The display colors are
changed in the MAP mode as follows: green to cyan,
yellow stays the same, red to magenta, magenta to
blue. When using the MAP mode, the gain control is
used to adjust the prominence of ground features.
(2) RANGE Selector Control Knob. The
range selector knob selects for displays, range at 5,
40, 80, 160, and 320 nm. This enables the
pilot to select the displayed distance for most weather
conditions that exist. There are four range calibration
rings on each range setting with numerical read-out of
their range in nautical miles. In addition to the range
rings, bearing markers are positioned dead ahead and
20° to either side of the aircraft heading for use in
judging the storm bearing and necessary heading
(3) Weather Radar Control Indicator TILT
Control Knob. The TILT knob is used to adjust the
radar antenna angle + 12°, relative to the horizon.
Proper tilt adjustment is one of the most important
factors in obtaining optimum use from the weather
radar. Too high an angle will pass the majority of the
radar beam above the storm cell, particularly when the
storm is a great distance away. Too low an antenna
tilt will clutter the indicator with ground returns. The
maximum distance at which ground clutter can be
obtained will depend greatly on the terrain and aircraft
altitude. The tilt setting is displayed in the top right
corner of the screen. When the STBY switch is in the
ON position the designation is replaced by STAB.
(4) BRIGHT / GAIN / MAX Control Knobs.
These knobs control display brightness and manual
adjustment of gain. Brightness of the display screen is
fully adjustable to compensate for a range of ambient
light levels, while automatically maintaining equal
brightness between the three colors displayed.
Likewise, the gain control can be manually adjusted in
both weather and ground mapping modes to provide
maximum flexibility in target interpretation. Whenever
the gain is varied from the preset maximum level, the
screen will annunciate VAR to remind the pilot to reset
the gain for standard intensity levels.
(5) STBY OFF / ON Selector Switch. The
selector knob permits the pilot to select gyro-stabilized
control of the weather radar system. In the ON
position, the radar's antenna scan is kept parallel to
the horizon and at the same relative tilt angle
previously selected. The displayed view is kept
straight and level, despite changes in aircraft pitch and
roll, thus preventing ground clutter from wiping out
potential weather targets.
c. Weather Radar System Operation.
Never operate the weather radar in the WX,
WXT, or MAP modes on the ground when
personnel are forward of the aircraft wing
and within 5 feet of the aircraft nose.
Failure to observe this warning may result
in permanent damage to the eyes and other
body organs of those persons.
reliability, it is recommended that the
aircraft engines be started before applying
power to the weather radar system.
(1) Turn On Procedure. Mode selector
switch Turn clockwise past detent to SBY position.
(2) Operating Procedure.
1. Mode selector switch TEST. Verify
that all four colors are present.
If TEST mode is bypassed and WX, WXT, or
MAP mode is selected, the display will light
up, and the warmup annunciator in the
lower left corner will illuminate. The
transmitter will become operational after
2. Mode selector switch SBY while
taxiing and until clear of personnel,
then as required.
(3) Shutdown Procedure.
1. Mode selector switch OFF.
3B-29. RADAR GRAPHICS.
a. Description. The KGR-358 radar graphics
unit interfaces with the weather radar system (KWX-
58), and receives navigation data from the flight
management system (KNS-660). The unit can display
NAV 1 or NAV 2 or both in a weather overlay, or as
navigation information only display. In addition, NAV
information can be viewed in a 360° (circle) display
with weather in the top 90° sector. Two checklist
modes are also provided for complete checklist
capability when utilizing the pocket terminal.