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Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
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OCR for page 85
s
Recommendations
The committee's recommendations are listed under four broad
categories: general, detection and prediction, aircraft performance
and operations, and research. The numbering of the recommendations
does not signify any priority. The broad spectrum of specific
recommendations reflects the complexities of the low-altitude
wind-shear problem.
GENERAL
1. NEED FOR AN INTEGRATED WIND-SHEAR PROGRAM
To provide for the safety of the flying public, the FAA and the
aviation industry should address the many facets of the low-altitude
wind-shear problem as a whole. The FAA should develop and implement a
coherent and sustained program for coping with the educational,
meteorological, technological, and operational aspects of low-altitude
wind-she ar haz ard s .
2. WIND-SHEAR EDUCATION PROGRAM
The FM and the industry should prepare and disseminate as widely
as possible updated and authoritative information on wind shear.
Informational materials should stress avoidance of wind shear and
should describe flight control techniques for recovery from
encounters . The information should encompass al 1 of types of
aircraft, with appropriate guidance for each class. It should include
recommendations on the most effective means of training pilots.
The FAA should revise and update its 1979 advisory circular
(AC 00-50A) on wind shear and the Airman's Information Manual (AIM) to
present the latest information, including detection techniques,
alerting and warning procedures, effects of wind shear on aircraft
performance, and procedures for recovery from wind shear encounters.
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3. PILOT/CONTROLLER COMMUNICATIONS
The FAA should promote the us e of s tandardized terminology and
improved communications between flight crews and control towers. A
standardized system of pilot reports (PIREPs) should be developed for
reporting low-altitude wind shear encounters. PIREPs should be
mandatory and should include a report of the location, severity, and
nature of the shear encountered--in consistent, standardized
terminology. Controllers should communicate such reports to all
flight crews in the vicinity. In addition, techniques for the direct
broadcast to pilots of wind shear data from LLWSAS or other sensors
should be investigated.
4. WIND SHEAR DETECTION SYSTEM DEVELOPMENT
The FAA should select a site to test direct and remote-sensing
techniques in a complete system for detecting low-altitude wind shear
and for providing information to pilots and controllers and to test
the use of the information in the air traffic control system. The
test site should be at a major airport where wind shear conditions are
relatively frequent.
DETECTION AND PREDICTION
5.
THE LOW-LEVEL WIND SHEAR ALERT SYSTEM (LLWSAS)
LLWSAS is the only system currently available in the near term for
detecting low-altitude wind shear on an operational basis and every
effort should be made to assess and improve its performance.
Opportunities include, but are not limited to, better signal
processing, reduced spacing between and increased number of sensors,
improved sensor response and improved wind-display techniques and
criteria for issuing wind-shear warnings, and the use of ground-based
pressure sensors to augment LLWSAS information. An improved LLWSAS
system is being developed for installation at New Orleans
International Airport. This upgraded system, to be operationally
tested in early 1984, should provide the basis for modification of
current LLWSAS installations and for improved system performance for
future installations. Depending on the New Orleans test results, the
FAA should modify existing LLWSAS systems and install improved systems
at all high-traffic density airports with terminal automation systems
(153 airports) where there is likelihood of the occurrence of
dangerous wind shears.
6. RECORD AND ANALYZE LLWSAS DATA
LLWSAS wind measurements should be recorded and analyzed to
evaluate the system's performance and to learn more about the climatic
properties of low-altitude wind shear. This should be done at all
airports equipped with LLWSAS.
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7. USE OF AVAILABLE RADAR DATA
The existing network of weather radars, operated by the NWS,
should be used more effectively to judge the likelihood of wind
conditions. These radars detect rain showers, thunderstorms, and
phenomena often associated with wind shear. Information from weather
radars should be made available to air traffic controllers in a timely
and easily understandable fashion.
8 . NEXT GENERATION WEATHER RADAR (NEXRAD )
The next generation Doppler weather radar system (NEXRAD) should
be developed and installed with all possible speed. This long-range
radar system will serve many national needs related to severe-weather
detection, forecasting, and warning. For aviation, the NEXRAD system
can be used to detect and monitor weather situations along flight
routes and, if located at or near some airports, to detect
low-altitude wind shear or its precursors. Moreover, the Doppler
radar will advance the rate of development of radar techniques for the
detection of low-altitude wind shear and the development of dedicated
Doppler terminal radars.
9. AIRPORT TERMINAL WEATHER RADAR
The FAA should take immediate action to develop a pulsed Doppler
radar system that can be used to observe weather conditions at and
around airport terminals. This terminal radar system should be able
to operate with a high degree of automation and to provide information
on low-altitude wind-shear, turbulence, and rainfall intensity. Such
a radar must be capable of supplying information updated each minute
and must have such features as ground-clutter cancellation and
adequate spatial resolution.
10. USE OF AIRPORT TERMINAL WEATHER RADAR OBSERVATIONS
For terminal Doppler radar to be most useful to traffic
controllers and pilots, a concerted effort should be devoted to
developing procedures for analyzing, displaying, and using its
observations.
11. AIRBORNE REMOTE SENSORS
Research should continue on the use of airborne Doppler lidars and
microwave Doppler radars as a means for detecting low-altitude wind
shear.
AIRCRAFT PERFORMANCE AND OPERATIONS
12. WIND-SHEAR EFFECTS ON FLIGHT CHARACTERISTICS
The FAA should sponsor analytical and simulator investigations to
determine:
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o The wind shear penetration
transport aircraf t, based on various
guidance, and control systems.
and recovery capab i 1 ities of
onboard do te cam ~ i On
The effects of wind shear on various typical categories of
general aviation aircraft and helicopters so that authoritative
information on their response characteristics and pilotin
techniques in wind shear can be provided.
13. AIRCRAFT OPERATING PROCEDURES
The FAA should ensure that air carriers and other commercial
operators instruct flight crews on what to do if they inadvertently
encounter a l.o~altitude wind shear during takeoff or landing. In
addition, the FAA should encourage operators of jet aircraft to
incorporate in their manuals the operating procedures recommended in
its advisory circular on wind shear. Aircraft manufacturers should
recommend configuration-change sequences (gear, flaps, power,
spoilers, etc. ~ that provide the highest probability for recovery from
a wind shear encounter. Pilots should be taught to exceed the normal
maximum thrust limits and to go to emergency thrust when necessary.
14. GUIDANCE AND CONTROL AIDS
Onboard sensors and guidance aids should be evaluated in a
systematic manner to determine their merits for future development and
for possible retrofit in existing aircraft. These include flight
director modifications, ground speed/airspeed flight management
systems, vertical-acceleration sensors, and energy-rate sensors.
Angle-of-attack indicators should be added to the cockpit
instrumentation of transport aircraft for use in maneuvering through
wind shears . Angle o f attack should be provided either as a separate
variable or as an input to other command displays. Sensors should
provide flight crews with a voice warning of a hazardous wind shear.
15 . STANDARDI ZATION OF WIND-SHEAR MODELS
The FAA should spons or a program to devel op and de fine
standardized models of wind shear based on the latest meteorological
data. These models are required for design and certification of
aircraf t subsystems and for use in training simulators. The FAA
should include other government agencies, aircraft manufacturers,
commercial operators, and any other interested parties in the program.
16 . CE RT IF I CAT I ON OF ONBOARD SY STEMS
The FAA should update its certification requirements for airborne
wind-shear alerting, flight guidance, and automatic control systems.
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17. WIND-SHEAR SIMULATION TRAINING
The FAA and the industry should cooperate to investigate new and
innovative ways to make available the best possible simulation
training for wind shear to the largest possible number of pilots,
including general aviation pilots.
RESEARCH
18 . EFFECT S OF HEAVY RAIN
Inves tigations should
aerodynamic
· Ha ~ ~ ~ ~ .
cant inue on
charac teris t ics
how heavy rain af fects the
low-speed aerodynamic characteristics of aircraft. Particular
attention should be paid to the possible adverse effects of heavy rain
on aircraft lift, performance, and controllability, including its
effects on wind shear detection and flight sensor systems.
19 . RE SEARC H ON THE NATURE OF LOW-ALT ITUDE WIN1) SHEAR
More must be learned about the various kinds of wind shear and the
meteorological conditions that cause or are associated with them.
This knowledge is needed to reduce the hazards represented by
low-altitude wind shear. Research should include additional field
observations and the construction of theoretical models over the
relevant scales--from about 1,000 feet to 10-20 miles and from minutes
to hours.
The existing body of data obtained by various research
should be reexamined and augmented, at an appropriate time, by a
programs
.. ~ field
~~ ~ ~~ ~ ~ the data
field
program In the numlo southeastern united states. Analyses or
obtained from the JAWS Pro ject should be used to plan any new
investigation. Basic research into the origins of strong thunderstorm
downdraf ts and possible forecast methods should be an important
component of any new program.
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Representative terms from entire chapter:
doppler radar
