The Committee is aware that there are increasingly serious constraints on the movement of all classes of aircraft at many U.S. airports. This condition is spreading rapidly to Europe and the Far East. These constraints can be described as congestion—the problem of trying to fit more and more aircraft into the same amount of space. Defined more broadly, the problem lies in the limited capacity of airports to accommodate aircraft on the ground, the limited capacity of the air traffic management (ATM) system to accommodate aircraft in the air, and the difficulties in integrating the two. A recent report by the Transportation Research Board of the National Research Council 1 outlined seven alternative strategies for accomplishing long-term increases in capacity at the nation's airports. These range from incremental improvements of existing systems to complete reconfiguration of the current systems to incorporate advanced management techniques and technology. Although the Committee on Aeronautical Technologies was not constituted to investigate these issues in detail and was not chartered to recommend specific approaches, it is clear that opportunities to expand existing facilities will be severely limited in the future. One possible approach for addressing the problem of congestion over the long-term is through the application of advanced technology to develop new airport and ATM systems. This approach concurs with the Transportation Research Board recommendation for a coordinated approach that includes expansion of current facilities over the short term and incorporation of advanced systems over the long-term. This brief chapter discusses in more detail the issues of capacity and congestion as they relate to airport systems and to current and future ATM systems. The boxed material summarizes the primary recommendations that appear throughout the chapter, with specific recommendations given in order of priority, and the benefits that can be gained through research and development aimed at aircraft operations.
Coordinated activity should be undertaken between NASA and the FAA to significantly increase the capacity of the worldwide aviation system, beginning with the U.S. domestic ATM system.
Every airport has a distinct personality profile consisting of runway/taxiway geometry, terminal/ramp configuration, usage by time of day, servicing facilities, noise and other environmental limitations, weather conditions, and user operational policies.
The most obvious solution to the ground congestion problem is more concrete (new airports, new runways, new taxiways, more ramp space), but this is expensive, time-consuming, and in many cases exceedingly difficult because of local objections to most forms of growth. Fortunately, considerable improvement is possible through simultaneous use of multiple runways, reducing aircraft separation on the runway, and more optimal routing of both aircraft and vehicular traffic on the ground. The Committee believes that implementation of the Global Positioning System (GPS) would greatly enhance runway and taxiway capacity. Clearly, the National Aeronautics and Space Administration (NASA) has a major role to play in this implementation and should work with the Federal Aviation Administration (FAA), the airlines, and aircraft manufacturers to bring it about as soon as possible. Furthermore, the Committee believes that an operations research program should be undertaken
Benefits of Research and Technology Development in Aircraft Operations
Air Traffic Management System and Airport Capacity
Optimal ground operations
Reduced takeoff and landing separation
Reduced aircraft separation in flight
Integration of international ATM systems
Reduced ATM system complexity
Greater on-board control
Integration of international ATM systems
ATM technology validation
Reliable automated systems
Precise relative and inertial position fixing
to evaluate and define each individual airport's problems. Such a program should include the development of a national data bank containing all factors unique to each airport, which would be monitored continuously to update and maximize the airport's efficiency. It is assumed that the FAA would be the primary sponsor of such an effort, but NASA should use its expertise in aeronautics to contribute wherever possible. This program could also provide clues regarding the best possible use of rotorcraft equipment in the discrete environment of each airport. With concentrated effort in this area, existing airports may not reach their ultimate capacity before 2000.
Although the Committee is concerned with airport terminal buildings and landside facilities, a literature review showed that previous work done by the National Research Council and others in this area, has been more than adequate. In particular, attention is directed to the Workshop on Future Airport Passenger Terminals.2 That report outlined 15 needs for the future of airport terminals. In the opinion of the Committee, none of these fall within the province of NASA. However, it is clear that as NASA works with industry to develop new concepts for advanced subsonic aircraft and high-speed civil transports it must remain cognizant of the impact those designs have on the airport systems that must accommodate them.
AIR TRAFFIC MANAGEMENT SYSTEM
The current global airspace system is a severely fragmented conglomeration of national and international interests that have little in common. In spite of this, the system manages to successfully separate both en route and terminal traffic, thereby maintaining a remarkable safety record. However, several factors suggest that the present system will not be able to continue to cope successfully with the ever-increasing volume of traffic (both flights and passengers) that is forecast for the next 20 years. The emergence of Eastern Europe, Russia, China, and Southeast Asia as major contributors to airspace congestion, and the imposition of increasing environmental constraints dictate the need for a complete revision of the current system.
The lead time to accomplish this overwhelming task is very short; therefore, the technologies involved must be explored, proved, and implemented by the year 2000. The United States is in a position to assume the leadership in technology development that will set standards and methodology for the future; this opportunity must not be lost.
At least seven distinct and equally important issues must be addressed:
automation of traffic control and aircraft position prediction in real-time;
establishment of digital data link (i.e., automatic altitude, heading, and speed logging);
direct access to on-board flight management computers for flight path guidance;
implementation of non-ground-based navigation, surveillance, and communication systems;
understanding of wake/vortex turbulence and its consequences;
provision for real-time weather information and analysis for use by the on-board flight guidance and navigation systems; and
development of provisions for rotorcraft to operate efficiently within the system.
Promptly and aggressively addressing these issues will ensure a continually improving safety record while at the same time increasing system capacity. In particular, implementation of the maximum practical global radar coverage would greatly reduce oceanic separation requirements, vastly increasing the capacity of that part of the system.
Considerable effort has been dedicated by both the FAA and NASA to all of these issues. Now, these efforts must be moved into the operational world in order to establish U.S. leadership of the global airspace system.
Taken as a whole, the seven issues listed above, when fully developed and implemented, will also lead to significant economic benefit to the worldwide transportation and aviation manufacturing industry, which will:
increase the capacity of the global airspace system;
save fuel and enhance safety, comfort, and the overall effectiveness of the ATM system by increasing the efficiency of flight path guidance;
provide an opportunity to open more airports and more runways to all-weather operation;
provide accurate real-time presentation and control of airport surface traffic;
eliminate potentially dangerous uncontrolled commanded avoidance maneuvers; and
provide a threshold for the entry of rotorcraft into the system.
The Committee has identified the following technologies that are needed for implementation of the global ATM system. NASA should focus its efforts, in cooperation with the FAA and industry, to expedite:
full integration of on-board communication, navigation, and flight management systems;
control and standardization of software for both on-board and ground-based computer systems;
development of a mission monitor to address any unacceptable developments that occur on- board the aircraft, in the satellite system, or in the communication system, whether in flight or on the ground;
development of a satellite communications system along with a global infrastructure to ensure clear and redundant communications; and
refinement of inertial navigational systems, including the use of fiber optics.