Trajectory ownership: dogfight or guiding principle?

Few elements of the SESAR Concept of Operations (CONOPS) have generated more controversy than the idea of trajectory ownership did. Regrettably, the controversy still boils. Some experts dismiss the whole thing as a “political dogfight”, others conduct lengthy debates on how trajectory ownership will work (or not work) in daily operations. They are both on the wrong track, revealing a fundamental misunderstanding of what the CONOPS is trying to say. It is time we put the matter out of its misery and recognize trajectory ownership for what it was always meant to be: a strategic guiding principle with a fundamental impact on future air traffic management.
First and foremost, we must realize that, except for the smallest and lightest aircraft, almost all flying machines are in fact business tools of differing sophistication. From rented aircraft to the most modern airliners, they fulfill a mission and are meant to generate revenue for their operators. The Sunday leisure flyers apart, this is true of business jets, crop sprayers, airline transports and even the military.

Yes, even the military, all claims to the contrary. Their business is war or the prevention of war, protection of peace or disaster relief, but they too have a budget in time as well as money and while they are not expected to make a profit, they may not waste funds either. Recognizing aircraft as business tools is the first vital step on the strategic level towards understanding the importance of trajectory ownership.
In the days past, a pilot plotted the track to be flown and then flew along it, following railway lines and roads, then flaming oil cans and eventually radio beacons. There was a trajectory of sorts and it was owned by the pilot… of course, as there was nobody else who would claim ownership. This is the case even to-day for aircraft flying VFR in uncontrolled airspace.
Things changed in a big way when air traffic control came along, making previously unimaginable traffic densities in all types of weather possible. Air routes were introduced to make things manageable for the controllers. Ground based trajectory predictors of various accuracies were implemented and the gap between what would be the ideal trajectory for the aircraft and what the ground could manage grew larger and larger. This airspace based paradigm of moving traffic was safe but not terribly efficient. The ground, understandably claimed ownership of all trajectories in exchange for a promise to do their best to keep everybody happy.
The effort was gargantuan, the results impressive but variable here and there. Most importantly, it was becoming clear that the limits of the existing air traffic management paradigm would be reached sooner rather than later.
While this evolution was taking place on the ground, aircraft and their operators evolved even faster. Air transportation grew up and became one of the most competitive business environments in the world. Few things facilitate progress more than does competitive pressure. The days when the Lockheed L-1011 was called the best three engine plane in the world (she actually had four engines but almost never made the ocean crossing with all of them still operating when making landfall) were soon forgotten with the jet engine revolutionizing air transport and the way airlines had to be run.
It was at this point that aircraft became sophisticated business tools that needed to be operated as such on the one hand and needed an environment that made this possible on the other.
Modern on board technology gave the flight crew previously unheard of accuracy in terms of current and future position awareness and the execution of maneuvers. Long gone were the days when sentences like “While being vectored by radar, flight crew are often unable to determine their exact position” in ATC manuals had some truth to them. This was backed up by sophisticated airline ground facilities (the Airline Operations Control centers or AOC) that prepared and fine tuned each flight’s trajectory which air traffic control never saw as the flight plan submitted was nothing more than a faint reflection of the real article.

What the plane flew in the end was usually an approximation where coincidence with the ideal trajectory was more the exception than the rule. Not that controllers did not do their best. It was just that the system slapped limitations on what could be achieved.
Civil aviation has an outstanding safety record and this is due in no small part to the exemplary safety level of air traffic management. When I was an officer of one of the air traffic controller associations in Europe, we even coined a slogan for us which said: Air traffic control – your safety in the air. I still believe that this is true. But it is not true to say that the primary business of air traffic management is to ensure safety.
Air traffic management must ensure that those sophisticated business tools can operate efficiently in an environment optimized for their mission and that this is done safely. In the more traditional view, where safety is a purpose, safety arguments are often abused to prevent change from happening (even where the change would in fact result in a safer system!). If however we see safety as a requirement, evolution and change are no longer limited by false safety premises. Change can take place safely, full stop. In this light, ATC facilitating a business environment is no longer an anachronism and safety is not an issue.
So, what is the status of the trajectory developed by an aircraft operator? It is the expression of its business intent, the best they can come up with considering the known limitations before air traffic management issues are factored in. It is no accident that this trajectory is called a Business Trajectory in SESAR (mission trajectory for the military, but as we have seen, it is the same thing).

We must also remember that, conceptually, an airline does not operate aircraft… they operate a network and this network is in fact represented dynamically by the trajectories they develop for the individual flights. The “product” of an airline is the seats they sell… and it is one of the most perishable products on Earth. Once the doors of the aircraft are closed, empty seats are like rotten melons. They represent a loss for that flight’s financial balance sheet.
There is a clear connection between the trajectories and the number of filled seats. If the trajectory (as part of the airline’s network) exists in time and place in a way that fits with customer demand (connecting possibilities, arrival times, etc.), most seats will be filled. Otherwise, lots of rotten melons on push-back.
Clearly, the business trajectory is an important resource to an aircraft operator, the best and only means of communicating their requirements for a given flight at a given moment.
You will also note that we show the trajectory as part of the airline’s network. This is an important development and impacts the pilot’s role in the future air traffic management system. While the flight crew remains at all times responsible for the safety of the aircraft, he is the boss over the trajectory only in so far as safety related modifications are concerned. The most efficient operation of the aircraft itself and the aircraft as part of the airline’s network has been and is being figured out in the back office, the AOC. The pilot, as the manager of that sophisticated business tool, must and will abide by the instructions encapsulated in the business trajectory.
Note: Clearly, some of the above does not apply to very small operators. However, the principles of trajectory ownership are the same also for them.
This brings us back to the question: who is then the owner of the business trajectory and why is this important?
When airspace users claim ownership of the trajectory, they are sending a powerful message to the designers of SESAR and NextGen. Create us a system that can handle trajectories recognized as part of our networks with all the business sensitivity this entails; treat the trajectories as client resources handed over to air traffic management for safekeeping with minimum distortion; create a business environment in which the sophisticated business tools can be operated to maximum effect safely…
Clearly, a debate about how trajectory ownership would be handled in daily operations misses the point. In a properly constructed system for trajectory based operations (TBO), the effects of trajectory ownership become part of the system itself and are not things to be struggled with on a flight by flight, operator by operator basis. Where the need to negotiate trajectories is properly supported by information management (SWIM), the “there is no time” argument also loses its meaning.
Of course, ownership conveys obligations as well as rights. When airspace users claim ownership of the business trajectory, they must realize that as owners, they will have obligations to implement information management, integrate with the air traffic management network and play by the rules. This paradigm change will not come for free but all indications are that the benefits outweigh the costs.

Trajectory ownership by the airspace users must be one of the most important guiding principles of future system design. It is not a political dogfight but it can bite everyone if not implemented properly.