Free Flight

[Brianking]

Read an interesting article in New Scientist this week, about the possibility that pilots would prefer to be able to calculate their own flight-path and not be bound by atc, except during approach. Seems there are quite a few adherents to this philosophy and there may be a strong case for implementing it. It's been tried already in a few areas. It's thought it would actually reduce the chances of near-misses, or actual (as in Switzerland the other week) collisions.

Seems to me that MS FS2k2 got there first!!

Brian

[stifler]

>Seems to me that MS FS2k2
>got there first!!

I would agree with that, i have been vectored to a particular runway and been given a heading in the opposite direction!!, made a very interesting landing too. I did notice another bug with the ATC though, I was cleard for takeoff at MAN on 6L and an Air France 747 was cleared to land on 24R, the rest is history, happened a few times at different airports.

[NightEye]

I don't see how FS got there first. The new system they are implementing, to my knowledge, is a GPS/ground station based tracking system that will allow aircraft to see each other on an MFD and do flight collision avoidance at their own discretion. Don't think the stock FS has such a feature? And if it did, this type of feature is a piece of cake to add into a video game; getting such a system to work in the real world effectivley is a major engineering task.

[mdklatt]

Free flight seems like a good idea to pilots, but controllers will disagree. It quickly breaks down in crowded airspace. Separation in such airspace is dependent to a significant extent on procedures. All the planes are on predetermined paths, possibly at predetermined speeds and altitudes. If you have flights showing up randomly and heading every which way you're going to have problems. Relying on automated technology and/or the pilots to sort everything out is not going to work becuase they don't the the same Big Picture that the controller has. By reacting to one potential collision you may causing others with planes you don't even know about. This already occasionally happens when pilots react to TCAS alerts.

We already have free flight to some extent. In wide open airspace or in the middle of the night it's not to difficult to get a direct clearance. If airborne TCAS technology improves free flight will be a possiblity. Another alternative is traffic forecasting. If everybody files a flight plan (which is required under IFR anyway), computers can "fly" the proposed route and project any conflicts with all the other flights in the system. In fact, a rudimentary form of this is already in place. That's why the clearance you get may be different from the flight plan you filed. ATC computers evaluate your route and choose a route that theoretically provides separation with all other IFR flights.

The problem with traffic forecasting is inflexibility. It only works if everybody departs on time and follows the flight profile expected by the computer. Any changes will invalidate the computer projections. This is where controllers come in, and why they will be needed for the foreseeable future.

[Brianking]

All very valid points, and they were made in the article I mentioned (the article may well be in the New Scientist web site, I haven't looked).
AS I understand it, the idea is to computer-control the whole thing, with a 'bubble' of airspace around each plane which may not be entered by any other plane. Thus there would be many more aircraft-free routings available, and freer selection of cruising altitude, so reducing the statistical possibility of conflicting paths. That might be easier for a computer to cope with, rather than having to shoe-horn all the aircraft into the same corridors and rely on sharp-eyed atc controllers to prevent mayhem!
Who knows? What I meant, when I said MS had got there first, was that under FS2k2 and the IFR planner, you (the pilot) can choose to fly at any altitude and can fly direct from A to B rather than stick to real-world air-corridors.
I'm just an innocent bystander and an occasional passenger, so I just sit back and watch the various interested parties fight it out!!

Brian

[mdklatt]

>Who knows? What I meant, when
>I said MS had got
>there first, was that under
>FS2k2 and the IFR planner,
>you (the pilot) can choose
>to fly at any altitude
>and can fly direct from
>A to B rather than
>stick to real-world air-corridors.

That's nothing new to FS. Nothing says you have to fly along airways when flying VFR or IFR (in the US anyway). In many parts of the country you can fly direct from VOR to VOR, waypoint to waypoint, or straight to your final destination.You do not have absolute freedom of altitude selection, however. Even under VFR there are altitude rules you must follow. In congested areas direct clearances are rarely given due to the problems I described above. Any pilot who files an IFR flight plan from Richmond, VA direct to Boston, MA is going to be in for a big disappointment.

[flyinggriffin]

I suppose the big problem with free flight is what happens when all hell breaks loose in the form of thunderstorms or multi state extreme weather. All those birds scattering to and fro trying to find a place to land will drive the controllers up the wall.
It still doesn't solve the problem of what to do with all those planes after they get to the approach phase of the flight. You still have to herd them around into some sort of order so they don't swap paint trying to get to the airport. The real problem with the airway system isn't the cross country phase, its the landing and takeoff phase.
When I started my instrument training, I wondered why the instructors in the ground school treated the flight planning phase somewhat casually. Unlike the private pilots ground school, gone was the emphasis on calculations worthy of physics. Yes the written test has answers only minutes apart, but when you get into the real world you find that if you are inflexable with your plans you may be in for a rude shock. You seldom get the exact clearance you plan for. Actually flying the system teaches you what routes to ask for, but you still have to be aware that there are times when your Burlington VT to Boston, seems to be routed by way of Newark NJ.