Aviation and the Global Atmosphere

Aviation and the Global Atmosphere
In 1983, the ICAO Council established a committee to identify and assess new technologies and make recommendations for the future development of air navigation.
After close analysis, the special committee on the future air navigation system (FANS) recognized that the existing air navigation system and its subsystems suffered
from technical, operational, procedural, economic, and implementation shortcomings. In addition to infrastructure constraints, conventional airspace organization of
flight information regions and their supporting infrastructure of routes and ground-based facilities and services are based largely on national rather than international
requirements. For these reasons, aircraft must plan their flights along strictly defined routes and be channelled, to a certain degree, so that air traffic controllers can
keep aircraft safely separated from each other.
8.2.2.2. Airport and Terminal Maneuvering Area (TMA) Operations and Capacity
In some regions, limited airport capacity is one of the main constraints on continued growth in air transport; this limited capacity results in congestion and delays. There
is also a lack of adequate awareness and shared decisionmaking among ATC, ramp, and taxi areas. In low-visibility conditions, movements are severely restricted,
and there is increased risk of runway incursion. Insufficiently developed taxiways and aprons also limit runway and airport capacity. Operational limitations for noise
control may also have a negative effect on access to and from key airports. Automated ground-based systems to manage departures and arrivals efficiently are not
available in most cases, and onboard automation is therefore underutilized. Published arrival and departure procedures-created to ease controller workload and ensure
separation between departures and arrivals-are often inflexible, indirect, and less than optimum.
8.2.2.3. En Route and Oceanic Operations
The existing worldwide route structure often imposes mileage penalties compared to the most economic routes (generally great-circle routes); it also takes into account
wind, temperature, and other factors such as aircraft weight, charges, and safety. Use of a fixed-route network often results in concentration of traffic flows at major
intersections, which can lead to a reduction in the number of routes and flight levels that are available. Studies on penalties to air traffic associated with the European
ATS Route Network alone suggest that ATM-related problems add an average of about 9-10% to the flight track distance of all European flights en route and in
terminal maneuvering areas (TMA) (EUROCONTROL, 1992). Lack of international coordination in the development of ground ATC systems exacerbates these
problems. Examples include inconsistent separation standards in radar and non-radar airspace and operation at less than optimum flight levels in oceanic airspace as
a result of communication deficiencies.
8.2.2.4. Meteorological Information
Currently, three main areas can be distinguished in which improvements need to be made in the way meteorological information is provided to international civil
aviation: Timeliness, presentation, and accuracy.
Timeliness problems are largely related to the inability of telecommunications channels in some regions to cope with increasing message traffic. As a result, tight
restrictions have been established concerning the exchange of operational meteorological information, which now does not fully meet flight planning requirements for
increasingly long-range aircraft operations. The presentation of meteorological information has also been largely dictated by the telecommunications channels used,
which have imposed a predominance of alphanumeric messages over graphical information, especially in the cockpit.
Finally, the accuracy of meteorological information needs improvement. For the en route phase of flight, the information provided is not always based on output from
the most advanced numerical weather prediction models. In the terminal area, up-to-date and accurate meteorological information may not be available to the pilot
because of congestion of voice channels and/or lack of modern observing systems.
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