On 12/02/2015, in ATC world, by steve
Hungary’s decision to get rid of all fixed routes in the Budapest FIR and so become the first place in Europe with true free-route operations signifies something that few people appreciate for the huge impact it will have once others also follow suit. The ability to fly any track in the en-route phase that is the shortest distance between the departure and destination aerodromes will save the airspace users billions and is something the airspace users have been asking for, for decades. I am sure many a retired air traffic controller will now scratch their heads and wonder: how are they going to manage all those aircraft without the routes acting as a reference for planning.
The answer of course is TBO, or trajectory based operations, where the controller is looking at the trajectories (eventually end to end) rather than individual aircraft and 20 minutes into the future… Of course there are only so many aircraft a controller can handle at the same time and a similar limit to how many controllers you can assign to work in a given volume of airspace.
If growing demand is to be accommodated, automating some tasks becomes inevitable.
Make no mistake, the tools and procedures currently being fielded in leaps and bounds by NextGen in the US and Sesar in Europe are little more than baby steps towards what we will need in the future.
One of the big problems with current automation concepts is that we look at the total ATM operation and then automate those elements which can be automated relatively easily and which is acceptable to the human controller. But the basic paradigms of managing traffic and providing separation hardly change at all. This approach will quickly lead to a wall which we cannot go around or jump over because of the legacy relationship between controller and automation. The current concepts are all limited by the requirement for the human to be able to take over if the system fails.
On 22/04/2013, in Buzzwords explained, by steve
Trajectory based operations or TBO figure frequently in current air traffic management related concept documents and discussions. When asked, most experts will say that they understand what TBO is… but scratch the surface a little and you will find that at best they all have a different understanding and at worst a completely wrong understanding of what TBO really means.
I am not going to bore you with yet another discourse on TBO, I have written more than enough on the subject already. This time I would like to hold a magnifying glass over the trajectory itself and give you what may prove to be a rather unorthodox view of this ever present yet ethereal thing that has many more uses than one would think on first sight.
As we know, trajectory based operations, at its simplest, means going away from the legacy airspace based air traffic management paradigm to replace it with a trajectory based one. In the legacy approach, experts try to guess the dimensions of the airspace required to accommodate the traffic demand and then force aircraft left, right and centre to fly in ways that fit the airspace. What is more, controllers focus on the aircraft with minimum look ahead times to discover and resolve conflicts. It is little wonder that aircraft often end up flying trajectories that have little resemblance to what the airspace user originally intended.
Under trajectory based operations, airspace is designed to accommodate the trajectories without distortions whenever possible and controllers consider the impact of their actions on the entire trajectory still to be flown. With appropriate decision support tools, they select intervention options that result in the least overall distortion of the trajectories concerned.
But what is this trajectory we are so often talking about? One possible definition of the trajectory is the series of points on the ground and in the air that describe the path the aircraft will follow. These points are not navigation aids but rather the kind of points we know from geometry; by connecting the points we get a visual representation of the path the aircraft will follow. We can identify any point on this path by its three spatial dimensions and the fourth dimension, time. This is how we come to know where the aircraft will be and when.
Some seem to think that a trajectory is from gate to gate only and there is no such thing as a trajectory during the turnaround. Here is then the first opportunity to consider the trajectory in a new light.
On 31/05/2012, in Buzzwords explained, by steve
The problem with traditional systems
In the traditional scheme of things, an aircraft will file a flight plan, containing a rather rudimentary description of its intentions. Air traffic management and air traffic control organizations then decipher the plan and create a trajectory for the flight as best they can… Very often this is but a poor image of what the airline concerned had in mind and then even this version is further distorted due to the need to limit sector loads or to provide separation.
We tend to think of the trajectory as being three dimensional but in fact the fourth dimension, time, is as important as the three spatial dimensions. This means that a delay on the ground is in fact a distortion of the trajectory which affects “only” the time dimension, but which can have serious consequences for the flight concerned.
Aircraft operators do develop the trajectories they want to fly taking many considerations into account and in the end, the trajectory represents their business intentions, the path on the ground and in the air they want to proceed along to ensure the most cost-effective conduct of their flight.
Traditional air traffic control is based on managing aircraft rather than trajectories. They do of course use the trajectory created in their systems from the flight plan to check ahead of the aircraft to see whether there is a conflict with another flight but this look-ahead is very short (in the order of 20 minutes or so) and tactical interventions rarely take into account their effect on the trajectory as a whole. Multi-sector planners are starting to appear but even these tend to have a limited scope and ability to keep the integrity of the trajectories intact.
Aircraft with sophisticated Flight Management Systems (FMS) can fly a trajectory with phenomenal accuracy but the prediction capability of the FMS is not always what it should be, especially because of shortcomings in the weather-modeling capability built into them.
On 09/05/2012, in NextGen, by mike@boeing
Air traffic service (ATS) data communications provide benefits in terms of increased airspace capacity and improved operational efficiency while also enhancing the existing high level of safety.
• Increased airspace capacity. In continental/domestic airspace, capacity is primarily increased through basic controller-pilot datalink communications (CPDLC) that reduce controller and flight crew workload as well as voice frequency congestion associated with routine communications. More specifically, basic CPDLC offers information exchange between the controller and flight crew for vertical, crossing constraint, lateral offset, simple route modification, and speed change clearance request and delivery. Effective strategic management of predictable and accurate aircraft trajectories in the future is also expected to increase continental/domestic airspace capacity; for example, delays due to convective weather will be mitigated by the ability to quickly supply complex route modifications to a large set of affected aircraft before departure. In oceanic, polar, and remote airspace, capacity is primarily increased through manual and automated reports that enable reduced aircraft separation by reliably providing surveillance data for separation assurance, flight plan conformance monitoring, and trajectory planning purposes.
• Improved operational efficiency. Operational efficiency is primarily improved through trajectory-based operations (TBO) that decrease aircraft fuel consumption and/or flight time, particularly in the face of constraints that would otherwise increase those parameters. Parallel integration of ATS provider ground automation, aircraft operator ground automation, and avionics (aircraft automation) and of controller, dispatcher, and flight crew operations enable TBO for rapid and accurate trajectory definition, coordination, and monitoring. TBO can be used, for example, to reduce flight time through user-preferred complex route modifications for in-flight aircraft as seen with Dynamic Airborne Reroute Procedures (see Figure 1) and to perform environmentally-friendly fuel-saving optimized profile descents as demonstrated by Tailored Arrivals (see Figure 2).
• Enhanced safety. Safety is primarily enhanced through accurate machine-to-machine exchange of precise data, such as complete three- or four-dimensional complex routes and latitude/longitude coordinates that resolve duplicate waypoint identifiers. These exchanges prevent gross navigational errors that could otherwise be caused by the flight crew manually transcribing detailed information.
On 10/02/2012, in SESAR's Palace, by steve
Only two and a half years into active SESAR development work, today the first initial four dimensional (I-4D) trajectory flight successfully took place. Thanks to the complementary expertise of the involved SESAR members (Airbus, Eurocontrol, Honeywell, Indra, NORACON , and Thales), the Airbus A320 test aircraft taking off from Toulouse to Copenhagen and Stockholm, successfully validated the capability of the aircraft system to comply with time constraints elaborated and negotiated with ground ATC system through air ground datalink communication. I-4D is a cornerstone of the SESAR programme as it is the first step towards more predictable flights.
“With this first I-4D trial flight under operational conditions, the SESAR members have proven that by working together in the framework of the SESAR programme real changes in the ATM domain are being brought about. Not only the aviation industry will benefit from optimised flights, but society as a whole”, says Patrick Ky, Executive Director of the SESAR Joint Undertaking.
The flight trial
On 28/10/2011, in The aircraft we fly, by steve
Curacao, Changi, Spaceport America, Zaragoza, Lelystad… What is common among these airports? Seemingly nothing but do not be misled by appearances. All these airports are getting ready to launch and receive sub-orbital flights in the not too distant future. While our industry is still trying to figure out how to integrate Unmanned Aerial Systems (UAS) into the civil air traffic management environment, private industry is throwing another challenge at us: sub-orbital vehicles.
Although sub-orbital flight may seem like the plaything of a few crazy bilioners, it is anything but. There is huge potential in this and it is not for nothing that so many entrepreneurs led by Richard Branson, as well as visionary airports, are getting on the band wagon. Even mighty KLM is involved, albeit only in a marketing capacity… for now anyway.
So what kind of aircraft or spacecraft if you like are we talking about and what do they mean in terms of air traffic management requirements?
A typical first generation sub-orbital vehicle is a kind of rocket powered machine that takes off from a runway and boosts itself to an altitude of around 330.000 feet at which space is commonly considered to begin. Skimming the top of the atmosphere the vehicle and all within it, experience a short period of weightlessness before it tips over and glides back to a runway to land. In a way this is reminiscent to what the Space Shuttle used to do but then on a much reduced scale.
On 13/09/2011, in ATC world, by steve
Back in the early 70s I was the vice-president of the Hungarian Air Traffic Controllers’ Association (HATCA) and we were busy searching for a good slogan for the association. In the end, we decided to use an adapted version of the slogan put out by the Canadians: “Air Traffic Control means you will have a safe flight”. The HATCA version became: “Air Traffic Control – Your safety in the air”.
Many many years later, when I was working in the airline Project Coordination Platform supporting the SESAR definition phase I introduced the idea of the “business trajectory”. This term referred to the trajectory defined by an airline, the one they wanted to fly and which best expressed their business intentions in relation to the flight concerned.
While the airlines really liked the idea, there was an immediate outcry from the controllers involved in the definition phase. How could I mention the term “business” in the same sentence with trajectory and air traffic control! ATC was there to ensure safety and business had nothing to do with it.
Recalling my time as HATCA president, I did not blame them. After all, when we were looking for the logo, we too highlighted safety as the aim of ATC and the word “business” did not cross our minds. We did this in spite of the fact that ICAO has been saying right from the start that the aim of air traffic services was to maintain a safe and efficient flow of air traffic.
Of course a lot has changed since then and while the importance of safety has not diminished, the relative importance of efficiency has grown tremendously. It is not an exaggeration to say that safety and efficiency are equally important if this industry is to survive. Concentrating mainly on safety is not enough by far… Our thinking must change so that the terms “safety” and “business” may coexist peacefully in our minds.
While the awareness to maintain safety is generally high in the ATM world, the business aspect still tends to be considered a necessary evil, even an affront to people anointed, after all, to uphold safety.
On 06/07/2011, in SESAR's Palace, by steve
The SESAR programme was launched on 3 June 2009. Now almost two years since its launch, It’s a good time to take stock of the status of the programme’s 300 projects, assess progress in the execution of the first SESAR release and the first project deliverables. In a short interview, Florian Guillermet, SESAR JU Chief Programme Officer, gives his evaluation of the programme and the first release, and looks at some of the challenges facing SESAR in the second half of 2011..
At mid 2011, what is the situation of the SESAR programme in general?
It’s almost time to celebrate the second anniversary of SESAR’s launch, and after two years of hard work we’ve made great progress: the ramp-up phase of the programme is complete and 85% of projects are now in full execution mode; the first concrete deliverables are arriving; all the programme management processes are now in place; and the programme delivery approach through SESAR Releases has been implemented. In addition, we are now fully integrating airspace users into the programme and they will directly participate in the execution of projects. Overall, we are on track…
On 29/04/2011, in Buzzwords explained, by steve
Trajectory Based Operations (TBO) and Service Oriented Architecture (SOA) are two concepts rather new to air traffic management (ATM) and apparently they continue to cause some head scratching when it comes to agreeing what TBO really means or how to define services in the ATM context. In this article I will attempt to explain a few relevant aspects of those concepts and will also try to visualize the concepts using the aircraft turnaround as an example.
Why the aircraft turnaround? Because we see that in spite of the original SESAR Concept of Operations having made clear that the trajectories of flights performed by the same aircraft are in fact always connected via the given airframe, some experts are now laboring to show that this is so and are trying to bring in new constructs to account for this “connection”. The trajectory does go through important metamorphoses during the turnaround and so using that phase of the operation gives us the opportunity to examine TBO and SOA in all their glory.
But first a few basics.
The concept of services.
“Service” is a word that can mean different things depending upon the context in which it is being used. In general, the context is based upon a consumer/supplier relationship. Further, a hierarchy of services can exist with, for example, a high-level service being made up of a number of lower level sub-categories of services. Therefore, it is very important to ensure that the nature, scope and detailed characteristics associated with each service are clear and unambiguous each time it is used, including defining who is supplying what to whom.
Services may be defined from a business perspective or an IT perspective.
On 21/03/2011, in FAB News, by steve
BLUE MED is the Functional Airspace Block (FAB) being put together by the States in the Mediterranean Sea area and their naturally sunny disposition is amply reflected in their newsletters, of which the second is now available.
FABs are exciting because the idea pre-dates SESAR and when we created the SESAR Concept of Operations it was designed to work in a true single European sky and not in what is essentially a larger scale fragmentation of that European sky. The participants in the various FABs are doing a lot to harmonize their operations but harmonization between the FABs themselves is another cookie… It is on that scale that things were always derailed in the past so it remains to be seen how they will be handled this time round.
Another aspect to think about is that SESAR uses a trajectory based paradigm while FABs continue to be based on the legacy, airspace based paradigm. A lot of work will have to be done (and little or none of it is visible so far) to move the FAB concept away from airspace orientation and towards the trajectory based concept that is the only viable future.
It would be good to hear from FAB experts how they are approaching the above issues.
In the meantime, read the second BLUE MED Newsletter here.