Telephonics RT-1601 RT - Weather Operations and Interpretation; WX Mode: Standard Weather Display

Search Operations
Weather Operations (Cont.)
30 RDR-1600 Pilot’s Guide TM106101(8/01) TM106101(8/01) RDR-1600 Pilot’s Guide
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7.0SEARCH OPERATIONS
7.1GROUND MAPPING
A secondary objective of the radar system is gathering and presentation of
terrain data. This data is represented in the form of a topographical map
that can be employed as a supplement to standard navigation procedures.
Target quality affects the indicator display in various situations. Use of the
SRCH gain control and TILT knob will often improve picture contrast so
specific ground targets are more readily recognizable.
Figure 7.1-1.Over Terrain
Illumination of terrain results in a “diffused” reflection of the beam. A portion
of this reflected energy is scattered back toward the antenna resulting in the
prominent display of land features as well as lakes, large rivers, shore lines
and ships.
Figure 7.1-2.Over Water
Calm water or water with swells does not provide good returns. The ener
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gy is reflected in a forward scatter angle with inadequate portions being
returned. The resulting display is “no target”. Choppy water provides better
returns from the downwind side of the waves. The resulting display is a
target whose intensity will vary with the degree to choppiness.
Above all, remember: Never regard any thunderstorm as LIGHT, even when
radar observers report the echoes are of light intensity. Avoiding thunder-
storms is the best policy.
DON’Tattempt to preflight plan a course between closely
space echoes.
DON’Tland or take off in the face of a thunderstorm in the
projected flight path. A sudden wind shift or low level turbu-
lence could cause loss of control.
DON’Tattempt to fly under a thunderstorm even if you can see
through to the other side. Turbulence under the storm could be
severe.
DON’Ttry to navigate between thunderstorms that cover 6/10
or more of the display. Fly around the storm system by a wide
margin.
DON’Tfly without airborne radar into a cloud mass containing
scattered embedded thunderstorms. Scattered thunderstorms
not embedded usually can be circumnavigated.
DOavoid by at least 20 miles any thunderstorm identified as
severe or giving an intense radar echo. This is especially true
under the anvil of a large cumulonimbus.
DOclear the top of a known or suspected severe thunderstorm
by at least 10,000 feet altitude. This may exceed the altitude
capability of the aircraft.
DOremember that vivid and frequent lightning indicates a
severe thunderstorm.
DOregard as severe any thunderstorm with tops 35,000 feet
or higher whether the top is visually sighted or determined by
radar.