Hi guys. Perhaps some of you ATPs or airline dispatchers or ATCs can help me out on this one. I know the PMDG forums isn´t the best place to ask this; but honestly it´s the one place where I feel most comfortable asking and where I know there are at least a few real top guns who know their stuff. I´m a private pilot in Brazil and usually when I fly online with my PMDG aircraft (737 and 744) I do so in America. In trying to simulate real world ops as much as possible, I always get my flightplans from flightware.comWhat I´ve noticed a lot lately is that many of these flightplans are built in a rather unfamiliar way for me. Whereas in Brazil we usually adhere strictly to published ATS routes (i.e airways) I see that many airline flights within the US have a lot of direct to segments (from navaid to navaid) cutting through airways that would get the job done as well. So my question basically is: what criteria do flight dispatchers use when building the airlines´ routes within the continental US? Why so many direct to segments? In terms of regulations, how is this done (i.e is there a law or regulaiton governing the building of routes)?Take for example the flightfplan for this american eagle flight from katl to kord: CADIT5 CADIT GLAZR HOPAP VOSTK HEVAN MZZ ROYKO3Thanks for your help.

Hi guys. Perhaps some of you ATPs or airline dispatchers or ATCs can help me out on this one. I know the PMDG forums isn´t the best place to ask this; but honestly it´s the one place where I feel most comfortable asking and where I know there are at least a few real top guns who know their stuff. I´m a private pilot in Brazil and usually when I fly online with my PMDG aircraft (737 and 744) I do so in America. In trying to simulate real world ops as much as possible, I always get my flightplans from flightware.comWhat I´ve noticed a lot lately is that many of these flightplans are built in a rather unfamiliar way for me. Whereas in Brazil we usually adhere strictly to published ATS routes (i.e airways) I see that many airline flights within the US have a lot of direct to segments (from navaid to navaid) cutting through airways that would get the job done as well. So my question basically is: what criteria do flight dispatchers use when building the airlines´ routes within the continental US? Why so many direct to segments? In terms of regulations, how is this done (i.e is there a law or regulaiton governing the building of routes)?Take for example the flightfplan for this american eagle flight from katl to kord: CADIT5 CADIT GLAZR HOPAP VOSTK HEVAN MZZ ROYKO3Thanks for your help.

Another thing you will notice in routes in America are the omission of published transition routes in the STAR, instead going for the direct route. The reason for this is the improvements of navigation equipment, such as IRS, GNS, RNP, no longer is it that vital to maintain on airways. Plus, with jetliners being able to reach higher altitudes right out of climb due to new wing technology, and RVSM, aircraft can be spaced out more vertically, and shortcuts can safely be made. Just going from VOR to VOR will not be accepted for a cross country route, but jumping from airway to airway aside from intersections are acceptable. So you ask, why so many direct segments? Because now this can be done in a safer, more precise manner, and it saves fuel.

It depends on the exact route I think - you do see airways used a bunch still:Example - the Jet Blue flight from Phoenix to New York JFK tonight:SJN5 ABQ J18 FTI J19 STL VHP ROD J29 JHW LVZ LENDY5There's a few direct segments in there between VORs over the midwest, but most of it is airways.There's a different formatting for flight plans that I like better than how flightaware shows them though - I've seen this on dispatch papers at a major US airline and I think it makes it a lot clearer what's going on:SJN5.ABQ.J18.FTI.J19.STL..VHP..ROD.J29.JHW..LVZ.LENDY5A single dot denotes a connected routing, so you know where the airway VIA/TO points are, what the transitions are for the SID and STAR etc. A direct routing has two dots, making it really easy to see at a glance.

Scott, thanks for the quick reply. I suspected as much. I´d say the vast majority of America´s fleet nowadays is capable of area navigation with an ANP much lower than the RNP, making it really unnecessary to navigate some of the older jet awys form vor to vor. Here in Brazil the upper airspace was recently restructured and many new rnav awys were added. They cut across central brazil with precious few navaids and mostly only fixes which are dozens (sometimes hundreds) of miles apart - probably saving airlines a lot of fuel and time.The newer acft can navigate these awys quite safely. Since we don´t have that many operational VORs, it´s hard to see direct to segments down here though. I suspect we´d see them more often ir we had a navaid network like your own.Tabs, I have also seen this structuring of flightplans lying around the net and I do agree it makes things easier to read at a glance. Thanks guys.

As Ryan said, it depends on the route. Flights into New York generally follow a very predictable route based on preferred routes published by FAA, where as those in the Western states will pretty much go direct unless there are airspace restrictions (such as most of Nevada and the California high desert). The FAA has publicly announced it is accepting direct routing as much as constraints will allow it, and has been adding RNAV "Q" routes throughout the country where traffic would benefit (such as up and down the pacific coast and between LA and FL across the gulf).

Flights into New York generally follow a very predictable route based on preferred routes published by FAA, where as those in the Western states will pretty much go direct unless there are airspace restrictions (such as most of Nevada and the California high desert). The FAA has publicly announced it is accepting direct routing as much as constraints will allow it, and has been adding RNAV "Q" routes throughout the country where traffic would benefit (such as up and down the pacific coast and between LA and FL across the gulf).

If you ask for direct routes in the East you will get laughed at/yelled at, aside from the time to time direct to shortcut of a dogleg. Preferred routes still reign supreme here.

If you ask for direct routes in the East you will get laughed at/yelled at, aside from the time to time direct to shortcut of a dogleg. Preferred routes still reign supreme here.

Preferred routes are still the best bet to get a cleared as filed, but even preferred routes seem to have more and more direct segments. But I do see what you have said. The east coast preferred routes are very airway based, while those that go across the great plains and the west coast are not so much anymore. But if it can be done, you can get cleared to direct, and it stands to reason that this will be more easily done in the west and great planes where there are far less major airports and air traffic is for the most part up high in cruise.I remember the first time flying on VATSIM into JFK, looking at all those STARS, and how they relate to the STARS for the nearby airports like KBOS and the other NY area airports, I very much appreciate the need to stay on those routes and fly them as filed.

At least below Class A, a lot of preferred routes are tied to altitude (I think they are in A, too, based on high Class A and low class A), so if you don't want a crappy routing, file for the altitude that's closer to a route you want. But, even with preferred routes, I don't think I've ever got an "as filed" clearance between DC and the NY area. Ever. I've gotten "blah, blah, blah, then as filed", but never straight "as filed". The preferred routes do have more direct segments, that's true, and frankly, a lot of the airways up the coast are pretty straight, so it isn't like you are zig zagging up the coast. Increasingly, with GPS and intersection points you can get pretty close to an optimal route. Here's a link to the databsae. Works fairly well for large airports. Not so well for satellites.http://www.fly.faa.gov/rmt/nfdc_preferred_routes_database.jspI think there's an excel sheet version too.

Here's a link to the databsae. Works fairly well for large airports. Not so well for satellites.http://www.fly.faa.g...es_database.jspI think there's an excel sheet version too.

Great stuff, thanks.

At least below Class A, a lot of preferred routes are tied to altitude (I think they are in A, too, based on high Class A and low class A), so if you don't want a crappy routing, file for the altitude that's closer to a route you want. But, even with preferred routes, I don't think I've ever got an "as filed" clearance between DC and the NY area. Ever. I've gotten "blah, blah, blah, then as filed", but never straight "as filed". The preferred routes do have more direct segments, that's true, and frankly, a lot of the airways up the coast are pretty straight, so it isn't like you are zig zagging up the coast. Increasingly, with GPS and intersection points you can get pretty close to an optimal route. Here's a link to the databsae. Works fairly well for large airports. Not so well for satellites.http://www.fly.faa.gov/rmt/nfdc_preferred_routes_database.jspI think there's an excel sheet version too.

Thanks a lot for the link Doug.

I would imagine that routes with less airways are to make them shorter, evade weather, etc. but a usual route would have plenty like what Tabs posted.

Its always an excellent forward subject to discuss.:(

Here in Brazil there is a prediction that VORs will be shutdown starting in 2012, so only RNAV routes will be available. When is this predicted in U.S.?

VOR's? What VOR's?None here is russia :(

Dan, VOR is short for Very Old Radiobeacon. :( Felipe I had no idea that our country was planning on disabling VORs. In my personal opinion this is a premature decision and they should rethink this strategy. Before we disable the VORs perhaps we should make newer technologies available that would increase safety in our country's aerospace: ADS-B, WAAS etc. Furthermore we can't forget that even though our nation's airfleet is incresingly younger and modern, most airliners depend on VORs and DMEs for position updating to maintain their actual navigation performance in par with the RNPs for terminal areas. Lastly, I think it's pretty stupid to depend solely on GPS technology even though it's been demonstrated to be very efficient and safe 99% of the time. It's been that way because America's Armed Forces have made it so. What if the US military decides to shut down the satellite network for whatever reasons? At least we should wait until GLONASS (Russian GPS) and Europe's systems are available before relying solely on GPS and IRS without radio updating. That's just my two cents! Needless to say I think GPS is the way of the future and we should definetly rely on it. I just don't think we should put all our eggs in one basket.