Imagine a situation in which two airliners are on a collision course.

What would happen? The air traffic controller (ATC) at the airport would try to identify the blips of the two planes on his radar screen and calculate the probability of a collision.

That’s no easy task, since he has to mentally construct a three-dimensional image of the flight paths of the two planes from the two dimensional radar image and project these paths over time.

Once he does so, he would then contact one of the pilots over a voice channel and instruct him to change course to avoid a collision.

Fast forward 10 years or less from today and reconsider the same situation.

This time, both pilots know exactly where each other’s planes are because data on the planes’ flight paths are displayed on the screens of their satellite-based navigational equipment.

They communicate with each other and the ATC digitally, automatically exchanging data on their location, direction and speed.

The data processing equipment also projects the flight paths over time, permitting the pilots to change course before tragedy befalls.

Welcome to the world of Free Flight.

The concept was first enunciated by an airline executive in the US in 1971, but remained in cold storage, unnoticed, until it was taken up for a discussion in 1994, after which the Federal Aviation Administration (FAA) got into the act. That led to a pilot project — Free Flight Phase 1 — in 1998 to field test equipment to introduce the concept into the country’s air navigation system.

The project is now entering its second phase of testing but it would be useful to first examine what Free Flight is all about.

Free Flight is more than just a collision avoidance system.

It is a concept of air traffic management that enables pilots to choose the best route, speed and altitude based on flying conditions such as weather and the amount of air traffic.

There was a time when aviators had this freedom to choose, but that was before the advent of air traffic control in the mid ‘30s.

Digital technology now promises to bring back some of that freedom to pilots by automating many of the tasks now carried out by ATCs.

In fact, Free Flight could even make flying a small plane almost as simple as driving a car with cruise control.

The present ATC system is not designed to handle even current traffic levels.

Even in developing countries on the global route map, it is about cracking at the seams.

In heavy-duty airports it is in danger of falling apart completely.

Congestion, flight delays and safety concerns are the order of the day and the prospect of airspace gridlock could loom within a few short years.

Small wonder then that some of the strongest advocates of Free Flight are the major airlines, it would help cope with growth in passenger traffic and reduce congestion at crowded airports by enabling planes to land with less spacing between them.

Flying more direct paths would also result in saving fuel and increasing productivity. Thus, although Free Flight may not be cheap to implement, congested airports and air routes may eventually turn out to be the more expensive proposition.

Much of the technology for Free Flight has already been developed and is available.

The attempt would be to investigate and implement projects involving these airspace control technologies — radio communications, radar systems, surveillance equipment — and supplement them with new technology to allow real-time data flow between ATCs and pilots, and better situational awareness to avoid conflicts.