Alliances are regarded, for example, as potential buyers or lessors of supersonic transports or other types of new air transports. The most significant new influence on 21st century aircraft will be the environment. Next-generation aircraft will be required to meet stringent requirements for engine emissions, in keeping with the U.S. Clean Air Act and the Kyoto Protocol. While new engine and airframe technologies will reduce emissions, fuel and airline operational practices may change as well. Politically, the world in the 21st century will be different as well.
Free trade is a growing phenomenon, serving to stimulate new services.
If trends continue, one can expect greater freedom of commerce and improved access to markets particularly between the largest trading partners, North America, Europe and eventually Asia and Latin America. However, the forces shaping the 21st century marketplace for transport aircraft appear to be more complex and less predictable than in times past. At this early stage, a forecast of how trends and forces will affect the new century depends largely on point of view. Such a marketplace will not only be grander in scope. It is likely that it will be much more complicated, harder to serve, definitely global and heavily involved with the environment.