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Old 10th Dec 2001, 15:43
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Thumbs up free flight

I have been employed by a major European carrier (14 years now) flying the Boeing 747 classic. The last few days I have had the privilege of looking into our future. I have flown with conceptual software designed for, what is commonly called free flight. It basically allows for optimum routings to any two points within the system. The pilot is given the tools to separate him/herself in the most optimum fashion. ATC’s input is basically assigning sequence numbers, during the final phase of the flight. The test I took part in were to asses the descend to landing phase of flight. Not originally foreseen when these folks started out, it worked fine with us in the sim. One of my colleagues who participated in the cruise part of the tests a while back remarked that it worked just fine, but when it really got busy the crew would become saturated. Then the testers told him the scenarios he had been flying were on average four times as busy as European Airspace is at peak times right now. There is still some work ahead but maybe you folks would like to read a bit about the future, which is coming our way faster then we imagined. The organization for which I did these tests is the Dutch version of NASA and is called the NLR. Here you find a link to their website, hope you find it interesting. Greetings Otterman. http://www.nlr.nl/public/hosted-site...ight/main.html
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Old 10th Dec 2001, 16:32
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Talking

Free flight to an ATCO means something entirely different!
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Old 10th Dec 2001, 19:35
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Otterman..

All very interesting stuff, and probably the way of the future for en-route traffic however..... I still can't see how this works in a busy TMA environment.

Consider the London TMA for example (one that I am MOST familiar with). Lets take departures. Okay the tower controller squirts them off much as now, and then what happens? You're on your own chum. So off you blast from 26R at Gatwick turning right direct EHAM. Except that you have an immediate confict with someone off Heathrow on their way to Frankfurt. Cue lots more activity on an already busy flight deck durring a critical stage of flight. For goodness sake don't have an emergency cos that will really screw things up and ATC aren't gonna be there to help (they're just traffic managers now, remember)

Consider the inbound scenario. Presumably with ATC allocating sequence numbers (as we do now BTW) you are going to swan around the sky until it's your turn, or are you going to pick out No.1 and follow him? A bit tough if he's come from the the ocean and you are coming "up the hill" from Paris. Oh, and don't forget to avoid all those departures from Heathrow/Gatiwck/Stansted and Luton at the same time.

I'm not a Luddite and I do actually see that point to point Nav will work in the higher level en-route phase of flight, combined with the ATC/Pilot tools that you have been testing. I can't see a solution in the TMA environment where things are pretty efficient now given the circumstances.

Next point is how you get ALL the operators to get equipped with the tools necessary for "Free Flight". This will require much bigger changes than have been required for RVSM approval, and many operators have shown great reluctance to get to even this standard.

To the Future.....

Rgds BEX
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Old 10th Dec 2001, 19:55
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Otterman

I totally agree with Bexil though I'm sure he really meant 26L at Gatwick. Bexil must be getting on a bit I think.

The TMA conflictions will trouble us ATCOs for a considerable time yet until computers are able to THINK.

If you think us humble ATCOs sitting in our bunker in West Drayton are exagerating then arrange yourself a visit.
Previous visiting pilots always have an enjoyable and eye opening day.
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Old 10th Dec 2001, 20:57
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Ooops.. Yes, sorry about the typo... I did mean 26 Left at EGKK!

Operating off the Right is whole lot of fun as well though (not for GMC)

Getting on a bit? Me? err, no, not that I'd noticed, but it does tend to creep up on you (or so I' told)

Rgds BEX
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Old 11th Dec 2001, 13:41
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Bexil and Essential Traffic;
Thanks for the response. In my initial post I mentioned that the descend to landing phase wasn’t originally foreseen by these working groups. My part of the testing was a result of the success of the initial cruise phase and was simply put a study of “how low can you go” using this system. We flew scenarios around the San Francisco Bay area. Lots of Special Usage Airspace, and busy departure/arrival streams, (especially the east and south), two close parallel runways at SFO, multiple busy airports, and Wx were also included. We were operating at peak usage. We did two days. The first day was total free flight. This implied that we were taken to an initial arrival point (about 100nm out) at which point you were to sequence yourself in for the landing, the route flown looked a lot like a STAR taking you right to the runway. So the aircraft ahead of you converged at predictable points, and their intentions were clear. The displays we used reached out to 180nm. We didn’t require more then this display limit in order to fit ourselves into a traffic sequence behind aircraft coming in from a different direction. Day two was managed. This required us to separate ourselves up to the abovementioned point, at which time ATC as we know and love it today took over with mostly speed reductions and some other instructions. This to see if it would increase airspace capacity measurably, over true free flight. We as a crew did throw some problems into the system, for example not being able comply with an instruction or not being able to reduce our speed because of flap problems. I must say that both days impressed me. Day one was a definite workload increase for the crew. Day two felt like it is right now but the information that you have as a crew aided situational awareness greatly. So using these initial points isn’t akin to squirting them out in an uncontrolled fashion. ATC is a long way from being obsolete especially in the dep/arr. phase. One of the problems with RVSM compliance was that it didn’t present enough savings for short haul carriers, just costs. This is partly true for free flight as well. For long haul it means tremendous savings. I think for the cruise part we have to look at the big picture. An aircraft leaves London goes to it initial free flight point (i.e. 150 nm out) under direction of ATC then proceeds in the most optimum fashion to its initial arrival point 150nm short of New York then ATC takes care of the arrival. In between optimum altitudes and speeds. London-Amsterdam won’t present the savings required to get the airlines to look at this seriously. Like all things in life we all will have to learn to walk before we can run. The cruise part will find great acceptance with the long haul airline community, and eventually the pilots and ATC will come around. Like solving a traffic jam in one spot the problem will be just move to a different area. The ground infrastructure is hopelessly behind any significant increase in traffic, but it would be nice not to have to sit on the ground waiting for some vague slot to open for you to get on your way. Sorry for the long reply, but I put the blame at my lack of eloquence in the English language. Greetings Otterman.
Ps. would love to visit you guys sometime at work. I am sure it would be as interesting as my visits to NY area control, Chicago O’ Hare Tower, and Edmonton ACC among others.
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Old 11th Dec 2001, 18:02
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Otterman..

Thanks for the extra info. Very interesting and perhaps a pointer to where we are going in the future.

It does seem to work well for the long haul en-route phases so perhaps we might see something like this on the North Atlantic in the not too distant future. My next query would be how to interface the "Free Flight" concept over the ocean with domestic ATC. A challenge but surely not an insurmountable one.

NATS here in the UK has made no secret that it sees itself as merely an ATC service provider so I would speculate that you won't be getting much input from them. A great pity as our own ATCEU (latterly the ATMDC) has done some stirling work over the years on advanced ATC/ATM systems. I wonder when this arm of NATS is sold off/closed down as not profitable enough?

You are of course more than welcome to visit LATCC. A phone call is normally all that is required and some ID in these security concious times. Be aware though that the en-route function is moving to the pantomime that is the New En-Route Centre at the end of January (oh yes it is!!)

Thanks again for the reply. Your eloquence in the English language is fine and much, much better than any attempt I might make at the Dutch Language.

To the Future..
Rgds BEX
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Old 11th Dec 2001, 18:08
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A quick P.S.

You mentioned that your "Free Flight" simulations were conducted in "The Bay Area". A mention of either is usually enough to get Scott Voigt on line with a few ideas....

Where are you Big Guy? We're talking SFO and one of you favourite topics here. (Whatever happened to Capt. Ba..... something or other. He was realy into this to anyone who'd listen on CServe)

Rgds BEX
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Old 12th Dec 2001, 05:34
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Hi Bexil;

I'm here <G>... Just have been up to my ears in work... As to NASA, I will be at Ames in January <EG>.

Otterman...

I was involved in some Free Flight sims using some actual US traffic. It worked great in some of the great north areas where there wasn't much in the way of traffic. However where there was any amount of traffic with military and such involved, the cockpit workload was well above what most of the crews wanted to deal with. In fact, our ALPA is now on file against the idea of pilots doing self separation after some of these tests.

As to the NLR <G>. Well they were quite proud with a computer program that they had a couple of years back that came up with all of the separation answers. The only problem was that it was moving EVERYONE in the problem instead of just moving ONE aircraft. The engineer kept saying, but look it works great. And he just couldn't get across the concept that he had messed with everyone instead of just stopping one aircraft 2000 feet below everyone else <G>.

Free flight is a wonderful idea, but as I teach in some of my classes it is something that is very ellusive. If you are going to have true free flight, you are going to need to have EVERYONE equiped for it. Then you are going to need more than just pilots sitting in a cockpit to determine who is going to do what. (ever seen an uncontrolled airport <eg>?)

Hope that was enough to chew on for a little while...

regards
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Old 12th Dec 2001, 12:32
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Thumbs up

Thanks Scott, I knew you wouldn't be far away.

So there you go. On the face of it Free Flight seems like a great idea, and a very attractive one for the bean counters (except when they have to PAY for the equipment). The practicalities are somewhat more difficult.

As I mentioned above, you need ALL operators to equip their aircraft and I don't think it's going to happen..... very soon. At the moment the current ATC system can handle everything from the lowest airways equipped PA28 to an all singing all dancing B777. Pretty impressive.

Still the future WILL happen. I wonder if we in ATC will have a say in it?

Rgds BEX
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Old 12th Dec 2001, 17:32
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The free flight concept has been around awhile, it's a lot like VFR isn't it? And the NLR has created a great video game. seem to recall them being big on microwave landing system.

Problems seem to be little matters like workload and coordinating everybody in a reasonable and efficient manner, which won't happen if the engineers and NASA (a huge public relations machine with some science attached) and R&D wonks would quit trying to be controllers and pilots. And controllers and pilots quit trying to be engineers (or God forbid R&D wonks).

Implicit assumption in most of the Free Flight stuff I've seen (mostly US, a little Euro) is that there can be something approaching perfect information on the position and intent of every aircraft that can be communicated to all the other aircraft. This is a tall order and not possible in today's technology and not practically possible in the forseeable future for every PA28 to 777 as has been pointed out in earlier posts.
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Old 12th Dec 2001, 19:11
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Again thanks for the replies. I told the people at the NLR I would be posting this subject, and they are reading along. So if you want to aid their research please feel free, it will be read.
As for the conflict resolution, there were three options given, vertical, horizontal, and speed. We ended up making most of the corrections in the horizontal plane. Mostly because you could see things coming well ahead of time, and very minor heading changes were required. When the conflict reached a certain limit (5minutes) the system would offer a way out. As a last resort TCAS was there (did not need it once). The software that we used is not ready for implementation, that is still some time off, (it was much too sensitive to traffic climbing or descending, we did not have the information to see what altitude the conflict was heading for). The system assumed that the traffic would continue on its present trajectory instead of levelling off somewhere. This resulted in us having to take action when none was required. But that is what all this testing is for.
The drivers for free flight are on several levels, as I see it. One is the tremendous cost savings for long haul operations. The other is the limit of the current system. The only way I could see this going is indeed phased implementation. Start with cruise (say above FL 250). And the Atlantic or Pacific might not be a bad place to start (as we did with RVSM). If ATC picks us up about 150 nm out for the descend and landing it would cover just cruising altitudes. Giving us a required time overhead an arrival fix is a good way to allow early sequencing. But I am getting ahead of myself. I don’t pretend to be smart enough to solve these issues, but there are people working on it who are. And I readily agree that my viewpoint is heavily skewed towards airline operations.
As for resistance from ALPA. I have served on our union council (one of the founding members of IFALPA). And my experience is that ALPA tends to scream their heads off (in a diplomatic fashion mostly), and then starts to think about a subject in earnest. RVSM, LASHO, close parallel approaches, and a good number of other subjects to name a few. You can already see this process towards free flight. In the beginning it was no way, never (too much responsibility is put in the cockpit, workload etc.), but they are already to the point where they are giving it a, maybe under the right conditions. This is still many years off and by that time, if they get the proper input into the discussion I am sure they will come around. Same probably goes for ATC.
Once again thanks for your replies. I am not strong enough on procedures in your field to countenance your objections, or the problems that you foresee. I was hoping that people reading this would start a “what if, and how do we solve it kind of discussion”. I wish you well, and maybe this subject will be talked about some more. Kind regards, Otterman
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Old 12th Dec 2001, 19:23
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Ratboy,
Also thanks for your input. I am sure what you are saying has been said by someone about any advancement that has been proposed. I have used it in its conceptual form. I was impressed, and I have been around this business a few years. You are right that it is not around the corner. But I am surprised that you are thinking in such big steps. RVSM was also first tried on a limited basis, and I am sure that this is the way we have to look at free flight. As far as MLS is concerned. I flew with it in Canada, and I thought it was great. It didn’t fail because of performance. Your making a point that sort of negates your own point. Technological advancements change the playing field. MLS is no longer required because of GPS, and free flight will become possible with technology that is already here, and what will come about because of research like this. I think that the international airline community will push this, because of the possibilities. TCAS is another such system that initially had a lot of resistance from within the ATC community and the cockpits. But I am incredibly thankful when I am flying over darkest Africa (or anywhere else for that matter) and the system is there to help me. We will wait and see, but is there input on what you would like these folks at the NLR, and their counterparts at NASA to know while they are doing this research. Greetings Otterman.
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Old 12th Dec 2001, 22:10
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Okay A question from me.

If we wanted to take a "first step" and set a Free Flight environment, say, on the North Atlantic in RVSM airspace only, just what equipment would be required? Is it available NOW? and at what cost to the operators? Would it be cost effective (keep the bean counters smiling)?

I can see that having target times and levels at oceanic exit points might well be an answer to the interface between the Free Flight area and domestic ATC. Target times and levels are already in use for Oceanic entry already as you know, so no major change required there.

Still can't see this working in the domestic EUR or USA ATC world.... yet.

Rgds BEX
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Old 14th Dec 2001, 15:52
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Bexil,
I am totally out of my depth when it comes to bean counting. At my company things seem to get assesed on its ability to earn itself back in about three years. Our oldest aircraft type (Boeing 747-300) is about to get a new EFIS setup (final phase starts on January first 2002). We had FMS's installed and are navigating using triple GPS. We are ready to participate in the future FANS airspace. Reduced spare availability and maintenance on the old equipment plus FANS were drivers for the upgrade. In my limited knowledge of costs I can't see free flight requiring an investment that would be much larger. On an international wide-body I think the costs should be recovered faster, then with our aforementioned cockpit upgrade. Because you can fly much more efficiently using the free flight concept. As for it being available now. The concept is being tested, so the answer will have to be no. But from what I understood there are no show stoppers. All the technology required is here already. You are getting a lot of should have, could have, and maybe's from me. So it is clear I am out of my depth. I don't have these answers. Maybe someone out there may read this and he/she might. As far as EUR and US airspace. They are two totally different creatures to me. I have flown both for the last decade. And the efficiency that the US offers us is much greater from a crews point of view. Direct routings out of LAX or SFO can exceed 1000nm. EUR in this regard is light years behind. I am sure that the experts have a billion reasons for this, but the difference is incredible. I am writting this in New Delhi, by the time we got to the Black Sea yesterday we had four transponder changes, only one direct routing of any significance over Germany (about 200nm). Numerous frequency changes to name but a few. The London airports are an absolute shining example of traffic management, matching or exceeding anything I see in North America. But the patchwork of ATC centers we see in Europe breed inefficiency when compared to the US. Everybody out there is doing their best, but it is too sad to think about sometimes. In upper airspace I can see this free flight concept coming into its own, but like I keep saying we are still a ways off. Greetings Otterman.
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Old 14th Dec 2001, 16:17
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Thanks Otterman.

Hopefully a few people who have read this thread will have had their imaginations fired and we may well see some sort of achievable Free Flight in the not too distant future, perhaps, as I suspect, on the North Atlantic.

As for the chaos that is the EUR ATC "System". While there are lots of well intentioned integration ideas (EATCHIP etc etc) there are still many European countries that have vested interests and have no intention of "giving up sovereignity" (as they see it) of "their" airspace. It will be a long time before we get a Single EUR sky.

In the meantime we will have to do the best with what we have. Thanks for your kind comments about London, I know Amsterdam is very well organised as well!

best rgds
BEX
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Old 14th Dec 2001, 16:45
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Otterman,
could there be a test-area for free flight matching the present RVSM area? I also see upper airspace as the first place to start practicing but I do think the traffic density is too high. Central Europe is like a huge TMA, traffic will enter and leave the system at a much too high rate. I believe in what was said in the beginning of the discussion: let´s try it across the pond.
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Old 14th Dec 2001, 19:24
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Before trying out free flight in the real world maybe some really good man in the loop simulations would be a good idea. What we do today is the evolution of the radar and radio technology of the 1940s and for thge next quantum improvement something fundamentally differeent will be needed.

Trying out Free Flight in areas with light or very predictable traffic first makes sense. NA in an off season may be good. When US FAA looked for a place to try pieces of free flight out they picked Alaska, and have been operating for about a year now with a subset of free flight to provide info to cockpit on other traffic, wx, etc. Lots of it GPS derived. Also does "controlled flight into terrain" avoidance (love those terms somebody comes up with ... used to be called crashing). One equiped aircraft lost so far with this... everyone walked away...pilot said he maybe should have had the special box turned on. Duhhh.

In areas with heavier traffic there will either have to be literaly highways in the sky and you don't deviate at all or some way of maintaining "situational awarenedd" in each aircraft. Maybe somebody on the ground getting the raw information and providing products to aircrew. Or maybe a third person in the airliner cockpit to do the "situational awareness" thing...I know, we could call him the navigator. Or maybe "aircraft commander", then the people in the front 2 seats could be the aircraft
drivers.
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Old 14th Dec 2001, 19:52
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AWST 25 June:

Upcoming flight tests over the Mediterranean will begin seeking answers to a key "free flght" issue - how to transition aircraft between areas of low-density traffic and the highly concentrated airspace of Europe.......

Ground testbed work is to begin this summer, with flight trials next year............

Italian air traffic provider ENAV will coordinate the Mediterranean Free Flight (MFF) program from Rome's Area Control Centre. Alenia Marconi Systems (AMS) will be a major player in the effort under a five year contract with ENAV.

Also supporting ENAV in the MFF work are Eurocontrol, the Dutch NLR aerospace laboratory, Telespazio, and the civil aviation administrations or service providers from Spain, France, Greece, Malta, the UK and Sweden.........
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Old 15th Dec 2001, 10:15
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Otterman;

You brought up one of the points that I was going to bring up in ref to free flight in the US... Some who profess some HUGE savings with free flight don't seem to equate the part that we send most aircraft direct somewhere when they aren't in very congested airspace. We have done it for years and will continue to do so, so you will be spending a lot of money on a system that is going to give you basicly what we are already doing for free... There are some systems which will allow us to do our jobs better which will help the operator, but I don't think that we are talking the kinds of money that they seem to fling around.

I remember in the early days when Capt. Cotton and Capt. Baiada used to throw some HUGE money numbers around when they talked about delays. I would then ask the question, how much percentage wise are delays effected by weather? The answer was normally in the 70 to 75% range. Ok, so of those savings you can take 70 to 75% off of it because none of this equippment is going to help you fly through thunderstorms or severe turbulence... Well no it won't... Ok, next issue, how many delays are due to not enough runways to land aircraft. Well we feel that about another 20% are due to airport constraints that are imposed on the airlines. Ok, so you say 20% of those delays are also something else that your box is not going to solve due to only being able to put one aircraft on one runway at a time. Well that is correct <G>... So what sort of money are you really talking about?

Then was the time that I was told I didn't understand the true economics of what they were talking about <G>...

As we say here in the US. It's runways stupid... The delays are either at the runway or due to weather. We have some very minor delays here at DFW even though it is a very busy airport. But that is easily explained when you look at the tonnage of concrete poured here... <G>

regards
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