Air Traffic Management

I have attended a very interesting seminar on the state of things regarding ASAS – Airborne Separation Assistance System – related applications.

The seminar was very interesting and I am sure that a lot of the applications [and from what I could understand in this remit we define application as the grouping of the technology, the functionalities and the procedures to achieve a goal] that are being developed, and which for some will be developed in the short term whilst others are for the longer term, will have a strong impact on AT[C]M and will be of an improvement to the system.

However,  as the title indicates, there is an aspect that I found worrying, which is the grouping of standardisation of specification and procedures together with a deep understanding on the human factor implications that the introduction of such applications will have on the system.

What worries me is that, from what I could indirectly understand during the seminar is that ICAO [there was no official ICAO stand on the issue presented] is severly lagging behind in this area, and is ready to let the systems to be specified, certified and used at local level before it specifies the functionalities, the performance levels and the procedures for use at a global level.

Some during the seminar compared the attitude to ACAS [the standard] and TCAS [the application] where ICAO let the application become operational before it made an attempt to coin the standard.  And this led to results many of us know of including:

• Lack of understanding of the human factor implications
• Procedures which were updated [refined] numerous times as experience was gained, which left many grey areas in how controllers and pilots had to react to the system
• Even though there existed a real need for a safety net such as ACAS, the solution was mainly driven by the technology related stakeholders.

I have already written about the way I perceive these problems in a previous article on ACAS so enough on that, but I am afraid that we are repeating the same mistakes where:

• Those driving the development of the ASAS applications are under estimating the impact they will have on the humans in the ATM system and as a result
• They are not investing sufficient effort [at least it seems so as for example none of the 18 presentations I followed during the seminar considered human factors] on human factors
• There does not seem to be leadership from a functional point of view, and the leadership seems to be industrial and technology driven [There were no presentations from - or considering the viewpoint of - the pilots and controllers who will use the applications]

With the results risking of being similar to the ACAS experience where we have valuable applications but which have serious shortcomings with regard of the understanding of the interaction with the humans who operate them resulting into serious safety problems.

So what can we do about it?

Well the human performance / factors / safety / training community as well as the ATCO and Pilot professional associations need to wake up to this problem.  We need to start getting involved and start lobbying on the issue.

We need to take the position that these applications NEED to be implemented, but they NEED to be implemented with the proper study on how they will interact with the humans in the system.  They need to be developed in harmony with the system including the humans. The role, responsibility, task, cognitive process changes of the human actors need to be well studied and adapted to the birth of these applications.  Adapted and appropriate procedures need to be written and training provided to those who need to make the shift to the new applications.  Recruitment analysis and training for new recruits need to change…

There is a lot to be done, but it can be done.

As for me, this is the second time I am writing on ASAS, I have also written on other occasions on the future of ATC. I will also continue to influence in as much as I can, from my position for others to start acting on this…

Only time will tell [and hopefully it doesn't] if the same mistake as with ACAS/TCAS is repeated…

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“When a pilot reports a manoeuvre induced by an ACAS RA the controller shall not attempt to modify the aircraft flight path until the pilot reports returning to the terms of the current air traffic control instruction or clearance but shall provide traffic information as appropriate.” (ICAO Doc 4444: PANS-ATM, Chapter 15, para 15.7.3.2)”Once an aircraft departs from its clearance in compliance with an RA, the controller ceases to be responsible for providing separation between that aircraft and any other aircraft affected as a direct consequence of the manoeuvre induced by the RA. The controller shall resume responsibility for providing separation for all the affected aircraft when:a) the controller acknowledges a report from the flight crew that the aircraft has resumed the current clearance; or b) the controller acknowledges a report from the flight crew that the aircraft is resuming its current clearance and issues an alternative clearance which is acknowledged by the flight crew.” (ICAO Doc 4444: PANS-ATM, Chapter 15, para 15.7.3.3)

“Note: the commander [the pilot] is required to climb or descend in response to an RA even if ATC has instructed him/her to take the opposite action.”Â

It is clear!

When the aircraft departs from its clearance in compliance with an ACAS RA, the controller ceases to be responsible of the separation between the aircraft and any other aircraft directly affected by the manoeuvre.

Or is it clear?

Before I try to explain what I mean, let us consider the present air traffic control paradigm* which is based on the controller being in control and striving to achieve, amongst other things, an orderly flow of traffic, and of pilots responding to and executing clearances.  And then there is an exception: ACAS RA.

As incidents have shown, it seems not to be so easy to exit this paradigm when an RA occurs.  Occasionally, controllers still issue clearances to aircraft executing an RA, at times in the direction of the RA manoeuvre but at others in totally conflicting directions.  And pilots still sometimes listen to controllers instead of their RAs.

So what could be wrong?

One may point at the lack of preparedness [see training] of the people making these mistakes.  But is it only a question of training?  Can adequate training solve all the problems?  Does the solution of the problem go a longer way than training?

Working in the training development field, I sometimes observe that we try to solve most of the complex problems by supplying [more] training, while in fact the most effective solution[s] would be better taken elsewhere.

So let us get back to the problem at hand: Controllers and pilots occasionally do not follow the rules concerning which manoeuvres should be executed when there is an ACAS RA.  I am not a human factors expert, but I think that even if training can go a long way, there are some other things that relate directly to human behaviour that would need to be dealt with at a more fundamental level.  Let us start by thinking of why the pilot would listen to a controller instead of the ACAS RA? Is it maybe due to a combination of habit, pressure and a degree of trust in the person issuing the clearance? How many times do we, even as assertive human beings, subconsciously make a subjective judgement of what we are being told based on who is telling us to do it?

Can we train to get over this?  To what extent can I train to make an objective judgement when I face people with whom I have a relationship based on a high degree of trust? Especially in situations where I am under pressure…In summary, apart from the objective judgement of which instruction to execute, what about the subjective judgment based on the trust that is built between the controller and the pilot?  Can we train to discard this?  Should we find other means to deal with the exceptions? Or should we find ways to include this kind of intervention within this trust relationship?  Food for thought…Then, what about the controllers still issuing clearances to aircraft even when knowing that these are executing an RA.

It is easier to say that “the controller ceases to be responsible…” than to acknowledge that the way we work as controllers [at least the way I did!] is to make a complex plan, and to execute it with an extended margin of flexibility to adapt it in the medium term, but with a significant reduction in the margin when situations become imminent. So in the example of an RA which produces a domino effect over a complex situation, is it that simple for the controller to cease to be responsible….?

The paradigm on which the controller’s work is based is that he or she has control over the situation.  It is also based on establishing and maintaining an orderly flow of traffic.  So how does this fit in with the chaos and loss of control that a [or multiple] RA manoeuvre[s] often cause?

Again, is reactive training composed of presenting the controller with RA situations where they should not intervene enough, or should we also train to deal with loss of control and chaotic situations?  Could we provide tools other than training, such as supplementary technology or alternative ways of working, that could help a controller who loses control to make sense of the situation?  Food for thought…[Yes, I know, down-linking the RA to the controllers is work in progress, but even this solution has been disputed by controllers and safety experts.]

Finally, what about the future?

In the future it is foreseen that there will be more situations where the controller will lose full or partial control of the situation. [I am referring for example, to the delegation of separation to aircraft] Can we use the lessons we are learning from the ACAS RA situation to encompass the new solutions, with enough consideration of the effect they have on the way controllers and pilots execute their responsibilities, and specifically on the way humans organise their work and relate to each other?

Technology, even when highly useful and when it has a proven record of saving catastrophic events from happening, (as in the case of ACAS) should not be introduced in semi isolation.  How the rest of the system, including the humans, need to adapt in order to accommodate it should be considered at a very early stage.  And training should not be seen as the only solution to achieve the necessary adaptation.

By way of a conclusion

The established procedure describing the responsibilities when an ACAS RA takes place, seems to be clear; however there needs to be much more than a description when it comes to complex relationships between the controller and the pilot and the way that each one of us works. Presently, controllers feel comfortable when they are in control and when the situation is well ordered.  Pilots are also conditioned to listening to controllers, and a trust relationship exists between the two parties.

Training to adapt to situations which are different from the norm will help; however, on its own, it is not enough.  Other things, such as considering softer issues such as the relationships between people and between people and systems, need to be considered.As regards to the future, those designing new systems which interfere with the paradigm of ‘control and order’ should probably consider more things than just training and written procedures…

[1] * Paradigm = A set of assumptions, concepts, values, and practices that constitutes a way of viewing reality for the community that shares them, especially in an intellectual discipline. Â

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