曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
microburst on aircraft which have the unfortunate
experience of penetrating one is characterized in
FIG 7−1−15. The aircraft may encounter a headwind
(performance increasing) followed by a downdraft
and tailwind (both performance decreasing), possibly
resulting in terrain impact.
AIM 2/17/05
7−1−48 Meteorology
FIG 7−1−16
NAS Wind Shear Product Systems
f. Detection of Microbursts, Wind Shear and
Gust Fronts.
1. FAA’s Integrated Wind Shear Detection
Plan.
(a) The FAA currently employs an integrated
plan for wind shear detection that will significantly
improve both the safety and capacity of the majority
of the airports currently served by the air carriers.
This plan integrates several programs, such as the
Integrated Terminal Weather System (ITWS),
Terminal Doppler Weather Radar (TDWR), Weather
System Processor (WSP), and Low Level Wind Shear
Alert Systems (LLWAS) into a single strategic
concept that significantly improves the aviation
weather information in the terminal area. (See
FIG 7−1−16.)
(b) The wind shear/microburst information
and warnings are displayed on the ribbon display
terminals (RBDT) located in the tower cabs. They are
identical (and standardized) in the LLWAS, TDWR
and WSP systems, and so designed that the controller
does not need to interpret the data, but simply read the
displayed information to the pilot. The RBDTs are
constantly monitored by the controller to ensure the
rapid and timely dissemination of any hazardous
event(s) to the pilot.
2/17/05 AIM
Meteorology 7−1−49
FIG 7−1−17
LLWAS Siting Criteria
(c) The early detection of a wind shear/
micro−burst event, and the subsequent warning(s)
issued to an aircraft on approach or departure, will
alert the pilot/crew to the potential of, and to be
prepared for, a situation that could become very
dangerous! Without these warnings, the aircraft may
NOT be able to climb out of, or safely transition, the
event, resulting in a catastrophe. The air carriers,
working with the FAA, have developed specialized
training programs using their simulators to train and
prepare their pilots on the demanding aircraft
procedures required to escape these very dangerous
wind shear and/or microburst encounters.
2. Low Level Wind Shear Alert System
(LLWAS).
(a) The LLWAS provides wind data and
software processes to detect the presence of
hazardous wind shear and microbursts in the vicinity
of an airport. Wind sensors, mounted on poles
sometimes as high as 150 feet, are (ideally) located
2,000 − 3,500 feet, but not more than 5,000 feet, from
the centerline of the runway. (See FIG 7−1−17.)
AIM 2/17/05
7−1−50 Meteorology
FIG 7−1−18
Warning Boxes
(b) LLWAS was fielded in 1988 at 110 airports
across the nation. Many of these systems have
been replaced by new TDWR and WSP technology.
Eventually all LLWAS systems will be phased out;
however, 39 airports will be upgraded to the
LLWAS−NE (Network Expansion) system, which
employs the very latest software and sensor
technology. The new LLWAS−NE systems will not
only provide the controller with wind shear warnings
and alerts, including wind shear/microburst detection
at the airport wind sensor location, but will also
provide the location of the hazards relative to the
airport runway(s). It will also have the flexibility and
capability to grow with the airport as new runways are
built. As many as 32 sensors, strategically located
around the airport and in relationship to its runway
configuration, can be accommodated by the
LLWAS−NE network.
3. Terminal Doppler Weather Radar
(TDWR).
(a) TDWRs are being deployed at 45 locations
across the U.S. Optimum locations for TDWRs
are 8 to 12 miles off of the airport proper, and
designed to look at the airspace around and over the
airport to detect microbursts, gust fronts, wind shifts
and precipitation intensities. TDWR products advise
the controller of wind shear and microburst events
impacting all runways and the areas 1/2 mile on either
side of the extended centerline of the runways out to
3 miles on final approach and 2 miles out on
departure.
(FIG 7−1−18 is a theoretical view of the warning
boxes, including the runway, that the software uses in
determining the location(s) of wind shear or
microbursts). These warnings are displayed (as
depicted in the examples in subparagraph 5) on the
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
航空信息手册2004下(78)
