¶ … ATC Free Flight Program The field of aviation is an ever-evolving field. The changes take place because of technological advancements that allow those in the field to reach new heights and new levels of personal abilities. The ATC Free Flight Program is one in which pilots have recently begun to participate in studies. The program promises to be innovative and exciting but the aviation field must move with extreme caution because of the human error factor that is involved.

In his book Commercial Aviation and Safety Alexander T. Wells explores the many factors that impact aviation safety. One of the things that he explores is the ATC Free Flight System and all of its participating factors of operation. While it is an extremely sophisticated and modern idea it still leaves room for human error, which in the case of aviation can be tragic.

Currently there are tests going on all over the nation with the new ATC system for free flight. It is based on software programs that allow the pilot more input as to his or her route and takes a lot of the work and stress off of the air traffic controllers who use to have to coordinate every change and every flight.

The URET software program is part of the FAA's Free Flight program and has been operating since 1997. It reached one million hours of use last May. "The FAA is delivering on its promise to put new equipment into the hands of the controllers," said John Thornton, director of the FAA's Free Flight program. "Increased direct routings mean shorter flights, which benefit controllers, technicians, pilots and passengers."

While many are exalting the many virtues of a Free Flight program critics caution the world of aviators to be extremely careful in implementing its use. If handled properly however, the experts believe the new system may revolutionize the industry while at the same time taking care of many historical problems that the old system had experienced. The former system was a system that worked when it was invented because there were fewer airplanes in the sky and fewer passengers traveling worldwide. In addition the technology at the time did not mandate the type of ability that today's system needs to maintain a safe and effective way of air traveling. A report in 1995 revealed the many dangers of old system that included increased delays, diminished efficiency and limited access to many needed data files. With the new Free Flight System coming to the forefront many experts feel that it may be the answer to the problems current aviation workers are experiencing. The former system presents problems with capacity as well as having excessive operating conditions that the new Free Flight System does not have.

The new Free Flight System is a system by which the pilot themselves have the freedom to plan, change or modify the flight plans that they are engaged in. The only time the air traffic controllers would have to be involved would be to be sure that safety was not being compromised during or following the changes implemented with the pilot decisions.

The pilots under this new program can choose their flight and speed in real time. It is handled through a software program that does many of the controller's former duties. "The only time there will be restrictions in this program is to prevent unauthorized flying, to ensure separation, to prevent an airport from exceeding its safety numbers for capacity and to ensure the safety of the flight. Even when a restriction has to be imposed that restriction is limited to the extent and duration of the problem that has been identified. Once that problem is corrected and safety potential is restored the flight returns to the control of the pilot.

The new free flight program provides two zones for each air craft. There is an inner zone referred to as the protected zone, and there is an outer zone that is referred to as the alert zone. If something comes into the alert zone the plane and ground control are alerted so that steps can be taken to avoid an accident. If something comes into the protected zone it is an emergency that requires immediate and quick action to rectify.

The size of the protected zone would vary inversely with the accuracy of position data, the communication rate, and the performance of intent monitoring systems. The Alert Zone represents the projection of the Protected Zone forward in time. So, for instance, increases in aircraft maneuverability result in a larger future swath in space. Whereas the inviolate...

Some of the obstacles being faced today are creating a seamless transfer from the old system to the new one. Training controllers to handle mixed system equipment until all planes, pilots and controllers can be trained to the new system exclusively. While this is occurring the role of ground as well as air personnel will go through redefining themselves.
Although FF will shift separation authority from ground to air, most experts agree that (certainly in the near-term) the controller on the ground will not be completely removed from the loop. But what will the role of the "Air Traffic Controller" be in the future, as we transition to FF? Will controllers still be responsible for tactical separation? Will they intervene only in case of system failures? Or will their job become more strategic (e.g., traffic flow management)? These questions have implications for the displays, tools, and procedures that will be used to carry out ATM in the future."

As the system was being put together and in the future as it is being implemented and ironed out there are several things that must be addressed. One of the most important problems to tackle is the question of how the aircraft would self-separate. This led to the development of rules of the air that all pilots will be required to follow in their free flight abilities. In addition it had to be decided how to handle situations in which no decision is being made and one must be handled soon. The system refers to this as a decision void which under the right circumstances could be deadly.

The cornerstone of our ATM concept was the set of "Rules of the Air," or Extended Flight Rules (EFRs), that could be used to conduct Free Flight simulations. EFRs were intended to dictate how aircraft should self-separate, under conditions of minimal (or no) ground intervention. They had to do so both comprehensively (i.e., for all possible traffic encounters) and unambiguously (i.e., each party had to have a clear understanding of the responsibilities of all aircraft). Further, to expedite pseudopilot training, it was decided that the number of extended flight rules had to be kept to an absolute minimum."

Free flight is an Air Traffic Management concept that allows for more freedom all the way around. The airspace users are able to have more freedom when selecting their routes. What this could mean as the system becomes comfortable is that they can fly direct routes and optimize air travel instead of being restricted and being forced into layovers due to air traffic controllers determining their flight paths.

Several studies have been conducted to determine the true safety of such a system with mixed results. The human factor is the largest concern for those who criticize the system. Once in the air a small mistake could mean a huge tragedy. The feasibility of the system has also been studied with positive results for the future.

Under the free flight system the air traffic controllers maintain control over the airplane until the pilot's flight desires are checked out and cleared through the ATM office. Once the plans are cleared and the aircraft departs the control is turned over to the pilot and he or she handles the flight barring any problems.

While the new program is an exciting new adventure for those who will be using it the air traffic controllers are faced with the daunting task of ensuring aircraft separation when the flight patterns and paths are not in the hands of the controllers. Their job is to oversee what the pilots are doing themselves and to intervene if mistakes are made. In some ways this will make the job of the air traffic controller more stressful not less stressful.

RESEARCH

Recent research was conducted and the results were promising. Using UK pilots the Free Flight System was tried and measured against the former system and the Free Flight System scored better in many areas. Because of the stop gap measures in place the Free Flight System allowed the freedom that has been desired by aircraft pilots for a long time and it created less work for air traffic controllers who could concentrate on more management issues.

A recent conference called for the immediate…