Tutorial
3. General Aviation
The possibilities exist to safely increase our air travel in the 21st century. However, the gap between demand
for higher speed transportation and its supply cannot be met using the current "hub-and-spoke" system.
An interstate "skyway" system could be developed to integrate thousands of smaller underused airports
and airspace in suburban, rural and remote communities. Safe, affordable and easy-to-use personal aircraft could
reduce typical inter-city travel times by 75%. We can achieve this vision if we harness the power of emerging technologies.
SATS (Small Aircraft Transportation System) is a NASA proposal adressing
these issues.
A different system currently being purposed for improvement is "Freeflight". Freeflight is a change in the airspace system being phased in by the Federal Aviation Administration (FAA). Aircraft would fly directly to the destination airport without following federal airways that can make the route much longer in time and distance. For example, during long flights, pilots follow a pre-determined airway for most of the flight. Under Freeflight pilots could request from air traffic controllers an alternate route that would allow them to fly more directly and perhaps at a different altitude and airspeed. Such a request would receive permission if during the descent phase of flight the aircraft can smoothly slip into the line of air traffic on approach to its destination airport.
For example. on a routine flight from Seattle, WA to St. Louis, MO, the flight plan might stipulate that the aircraft follow the route marked in red. The pilot after being given a weather briefing realizes that a change in the jet stream has given her the opportunity to fly a more direct route (green) at a slightly higher altitude to take advantage of flying within the stream. This would be more efficient in terms of time and fuel. Freeflight would make this decision possible.
Is it possible Freeflight would not require radar surveillance and sequencing by air traffic controllers? As was mentioned in the Efficiency and Aviation Capacity section of this tutorial, ADS-B, a system with some of the needed components is currently being tested in Bethel, Alaska. Freeflight could also be facilitated by current NASA research in Synthetic Vision.
If, for example, a passenger wished to fly from San Jose, California, to Jackson, Mississippi, this passenger
would have the following routes from which to choose depending upon the hub of the airline being flown:
Click on each route above to compare the different flight routes based upon an
airline's hub-and-spoke system.
NASA Research
NASA is responding to the need for better air traffic management
in the National Airspace System with an innovative approach: The Distributed
Air Ground Traffic Management project, or DAG-TM. In the current system,
from take off to landing, all flights are managed by air traffic control.
Pilots must ask controllers to check and approve requests for changes in
altitude or direction.
DAG-TM will change the way air traffic controllers, airline company dispatchers, and pilots do their jobs. Using an idea called “free flight,” NASA researchers are developing tools, procedures, and information-sharing technologies that will allow pilots to take more control of where they fly their aircraft. The aircraft will be equipped for independent maneuvering. If the flight crew needs to make changes to the original flight plan, they can take the safest and most efficient alternative without checking with the controller. By using intelligent software tools, enhanced cockpit displays, and advanced communication systems, pilots can maintain safe distances from other aircraft without controller intervention. Giving pilots better information and a responsibility for maintaining
separation of aircraft will reduce the air traffic controller's workload.
Allowing pilots to choose their own route around traffic and weather problems
will benefit the airlines by making detours shorter, saving time and fuel.
Improving air and ground systems to enable DAG-TM will safely increase
our nation's air traffic capacity and help airlines stay on schedule. |
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