Weather-Related Aeronautical Activities
In the area of weather services, personnel from the FAA continued to develop the Integrated Terminal Weather System (ITWS) to provide short-range forecast and warning notices for pilots and air traffic controllers. The ITWS prototype tests at the Orlando and Memphis airports continued, and a new test location at Dallas/Fort Worth went into operation. As a result of the prototype successes, the FAA made a decision to proceed with the full-scale development of an operational ITWS. Under its weather research initiative, the FAA combined resources with NOAA to award a contract for the development of a water vapor sensing system. United Parcel Services, Inc., agreed to have its aircraft carry these sensors and downlink the data for use in computer weather forecasting. Scientists expect that frequent observations of water vapor aloft will enable them to make significant advances in icing and storm forecasting. In FY 1995, in cooperation with NOAA's Forecast System Laboratory, FAA personnel conducted an operational evaluation of an in-flight icing forecast tool at the Aviation Weather Center. In addition, scientists from the National Center for Atmospheric Research conducted a field evaluation of ground de-icing and a snowfall computer tool at the Denver airport. The advances achieved by these investigators were transferred to industry via a series of cooperative research and development agreements.
In the area of icing, FAA personnel completed a report summarizing the latest research on icing conditions in freezing drizzle. The report recommended interim test conditions for evaluating the susceptibility of aircraft to icing in freezing rain and drizzle. In cooperation with NASA, FAA engineers continued to develop techniques for recognizing susceptibility to ice-induced tailplane stalls during icing certification testing, as well as simulation and analytical techniques from which to design and test ice-protection systems. FAA personnel began work on a new update of the Aircraft Icing Handbook, adding new information on the hazards of flight in large supercooled droplets. FAA researchers continued their investigation of technologies for ground de-icing and anti-icing fluids, their optimal application procedures, holdover-time guidelines, and associated aerodynamic effects. FAA personnel also undertook research, development, and evaluation of surface ice detectors and related technologies. As part of a cooperative effort with United Airlines, FAA scientists evaluated a surface ice detector system.
FAA managers commissioned Terminal Doppler Weather Radar systems in Denver, Memphis, St. Louis, and Kansas City, Kansas, during FY 1995. These systems provide for the timely detection of hazardous windshear in and near airport terminal approach and departure corridors and report that information to pilots and controllers.
During FY 1995, FAA managers also renewed the lease of the Meteorologist Weather Processor, with an option to continue the lease until the future deployment of the replacement Weather and Radar Processor system. This technology refreshment was necessary to accommodate the GOES-8 and GOES-9 weather satellites, changes to the National Weather Service communications, and a variety of format changes made to weather products that the FAA receives.
FAA personnel implemented a Wake Vortex program, which includes a joint effort with their NASA and industry colleagues to obtain site-specific capacity gains through procedural changes in sensor evaluation. Engineers completed the development of the Wake Vortex Training Aid, which addresses vortex issues from the viewpoint of both the pilot and air traffic controller, and distributed several thousand copies to the FAA and industry. In concert with DoT's Volpe National Transportation System Center in Cambridge, Massachusetts, FAA personnel established an automated Ground Wind Vortex Sensing System at Kennedy Airport in New York to monitor vortex translation in varying meteorological conditions and to evaluate new vortex detection sensors. Technicians completed testing with correlated vortex detection of a radar-acoustic sensor using that system. FAA specialists also worked closely with British officials to analyze valuable aircraft separation data from Heathrow Airport in London. The British reporting system has become a model for a proposed reporting system in the United States to provide a more useful data base of vortex encounters.
In an attempt to counter increasing congestion and delays at major airports, NASA managers initiated the Terminal Area Productivity program with the goal of safely and affordably achieving clear-weather capacity in instrument weather conditions. To determine safe aircraft separation standards, NASA researchers conducted numerous tests and investigations, such as an effort to identify and mathematically model wake vortices. In June 1995, scientists and engineers at LaRC validated a two-dimensional wake vortex model, which provided a theoretical basis for determining the proper spacing between aircraft during their approach to an airport to avoid the wake vortex produced by preceding aircraft. In another development, NASA personnel defined the concept for a new computer system to assist flight controllers, called the Aircraft Vortex Spacing System. To enhance flight operations and safety of aircraft on the ground, flight crew members used ARC's 747-400 full-mission simulator to evaluate their ability to navigate during ground taxi operations under various visibility conditions. In addition, the flight crews evaluated a three-dimensional auditory display system for ground operations, which embodied a computer-generated voice that provided verbal warnings of impending collisions with other aircraft or vehicles. Each of the 12 flight crews strongly affirmed that the auditory alert feature should be included in any future ground navigation system.
Curator: Lillian Gipson|
Last Updated: September 5, 1996
For more information contact Steve Garber, NASA History Office,