Finding or Creating IFR Routes

Finding or Creating IFR Routes

 

Introduction

This Lesson will outline the process for finding or creating realistic and ATC-friendly IFR routes.

 

What You Need to Know

Vocabulary

  • VOR Station: VHF Omnidirectional Range Station, which is a radio beacon used in aviation nagivation. It is named usually based on its geographical location, and has a three-letter ID which usually refers somehow to that name. When tuned on an aircraft's NAV radio, the Horizontal Situation Indicator (HSI) gauge has an Omnidirectional Bearing Selector (OBS) or "Course" setting which controls how the Course Deviation Indicator (CDI) needle reads the aircraft's track. The pilot tunes the VOR and sets the desired course, and the needle indicates whether the aircraft is tracking to the left or right of that course. The imaginary line tracing outward from a VOR on a specified course heading is referred to as a radial.

 

Concepts

  • Valid, acceptable air routes are necessary to give some sense of order to the chaos, so that Air Traffic Control has some method of ensuring planes don't conflict with each other; otherwise, the skies would be a free-for-all and controllers would have no way to form orderly queues for traffic separation.
  • Jet Airways (found on the Enroute High chart and designated with a J- followed by a number), and Victor Airways (found on the Enroute Low chart and designated with a V- followed by a number), are defined strictly by VOR stations and are thus all navigable by NAV radio alone. There are some T- and Q-routes that are defined by GPS points which require an RNAV-capable system to fly; these are marked in blue on the Enroute charts.  Outside of the US, other route designations exist as well.
  • Of particular note are the places where air traffic is passed from one ATC sector to another. Within his or her own sector, a controller can use their own discretion; when passing between ATC sectors, controllers are obligated to funnel traffic through specific "gates" in order to allow new planes to appear in a predictable manner on the next controller's scope.
  • The routes that are auto-generated by FS9 and FSX use simple VOR-to-VOR navigation and ignore common Jet Route conventions, so, they are rarely able to be accepted by VATSIM ATC; the same applies for simple direct routing from one airport to another, which is generally only acceptable for very short flights which take place all in one controller's sector.
  • Two great sources for realistic routes are FlightAware.com and SimBrief.com. FlightAware tracks real-world IFR flightplans. SimBrief pulls from a database of previously created and filed IFR routes on VATSIM and other simulator-based sources.
  • When desiring to fly between a pair of airports that is not in the SimBrief or FlightAware database, a pilot can construct his or her own realistic route by using SkyVector and SID and STAR charts.
  • If you are flying using the default FS9 or FSX GPS system, then regardless of whether the route is pulled from a website or constructed by hand, you'll need a tool for getting it into a format that can be imported into the GPS. The SimBrief Virtual Dispatch offers an export capability at the very bottom of the flight briefing page.
  • Flying by GPS is not the only option. If the route's waypoints are all locatable via VOR/DME and only include flying along VOR radials, it can be flown using just your NAV radios. Any SID, STAR, or IAP which is not marked "RNAV" can be flown by NAV radios alone.

 

More Detail

New VATSIM pilots often struggle with proper route planning, because the Microsoft Flight Simulator series does such a poor job explaining and creating air routes. Because VATSIM's Air Traffic Control network is modeled after the real thing, and the real thing keeps air traffic organized and efficient by having it follow standardized routes which follow predictable transitions from one ATC sector to the next, the air routes flown on VATSIM must generally speaking conform to the real-world limitations that are imposed upon them. Mainly, they need to utilize standard Jet and Victor routes (and other charted routes, outside of the US) as much as possible, and they need to adhere to this especially when crossing from one control area into another, or passing in or out of an Approach area. Controllers can accommodate routes which do not do so, but, it requires case-by-case coordination between controllers in neighboring sectors, and when handling a large amount of traffic this coordination can be too time-consuming for them to manage. To make life easier on pilots and controllers, it's always best to try to use IFR routes that are as realistic as possible.

However, two fantastic resources exist for sim pilots that can be great shortcuts for creating realistic routes that ATC will have no trouble with. The first is the IFR Route Statistics Search Page at FlightAware. If you enter two Airport ICAOs, the site will return a comprehensive list of all of the recent real-world flightplans that have been filed for flights between those two airports, including the route, the total distance, the cruise altitude, the flight number, and aircraft type -- even, if you click on an individual flight, the gate assignments, and the estimated and actual time of departure and arrival. Often, I will look on VATSpy for a city-pair that has ATC services which seem likely to stick around for a while, and I'll then come to this page not only to get a route, but I'll choose a flight that uses an aircraft type that I fly and then I'll assume that flight's callsign, aircraft type, and gate assignments as well.

The second, and possibly more awesome resource is SimBrief.com Virtual Dispatch Solutions. This is a system which allows you to enter the basic information of your desired flight such as the origin, destination, and aircraft type -- and the website will essentially do the rest, including researching routing options by searching a vast database of previously flown routes in VATSIM as well as other virtual flight simulation networks. It will check weather and recommend runways, select an alternate, calculate fuel with reserves, and generate a flight log, as well as offer an option to export the flight plan into a format that MSFS or X-Plane can recognize. MSFS users, if you have done this and saved it to your MS Flight Simulator directory, you can import the route into your default GPS system from the startup options screen by using the Flight Planning page and "Load Flightplan." (If you're using an add-on FMC or an aircraft model that includes one, you don't need to worry about that step.)

One thing to be careful about, if you imported a version of your STAR route that came off of one runway versus another, is that you get assigned that runway for departure. If ATC assigns you something else, this can cause problems because you can't alter the route using the default GPS. If this happens, you can simply request your anticipated departure runway, and unless there's some compelling reason they can't give it to you, they should be able to work with you. The same goes for your arrival. However, for either, they could also choose to vector you instead. On the departure end, they could give you vectors until you reach a point where you can re-join your filed route; for arrivals, there will almost always be a point at which you'll abandon the rest of the filed route and start following ATC's vectors to your approach course. You don't have to amend your flightplan in these cases -- the controller will make annotations as necessary to note what changes were made to your clearance as you go along.

Flying a route with the built-in GPS is usually just a matter of (a) having your autopilot on and in "NAV" mode (this will follow the path indicated by your HSI); and (b) having the navigation system set to GPS mode (a NAV/GPS switch somewhere in the cockpit). It's important to note the distinction between the two systems, because they will both have a mode marked "NAV", which mean two different things:

  • the Autopilot HDG / NAV selector will either point the plane where you have the heading bug set (HDG), or where the HSI is trying to guide it (NAV);
  • the instrument panel's NAV / GPS selector will either set the HSI gauge to indicate course deviation from whatever is tuned on the NAV1 radio (NAV), or whatever course and deviation info is coming out of the GPS (GPS).

Jet Airways (found on US Enroute High charts and designated with a J- followed by a number), and Victor Airways (found on US Enroute Low charts and designated with a V- followed by a number), are defined strictly by VOR stations. There are some Q-routes and T-routes that are defined by GPS points which require an RNAV-capable system to fly; these are marked in blue on the Enroute charts. However, all Jet and Victor routes may be navigated by NAV radio alone. If you ever wanted to try it, navgating by VOR is not as difficult as some people seem to think. Besides, it actually gives you something to do in the cockpit during cruise, which is never a bad thing in my opinion.

Let's say we are tracking the J50 route from east-to-west across MCB, the McComb VOR. We have it tuned on our NAV1 on a frequency of 116.7 mHz. As we approach it (and we're watching the DME count down the mileage), you'll see how we're following a line that is marked as the "095" radial -- however, we're headed westbound! So we need to set the course arrow on the HSI to the reciprocal heading, which in this case is 275. There should be an indication called a "TO/FROM" flag that indicates you're headed TOWARD the VOR; anytime this is the case, you'll need to track the reciprocal of what's on the chart. The middle section of that arrow will deviate to the left or right to tell us whether we're on the airway or off of it; if you have both the Autopilot and the HSI set to NAV modes, the aircraft should attempt to correct itself. If it's too far off-course, you as the pilot might need to intervene to get it close, and then let the Autopilot fine-tune it the rest of the way in.

Once you cross over MCB, you'll see that the J50 continues to the west on an outbound radial of 266 -- a slight left turn from where you were headed before. The instant you pass over the VOR, the needle will deflect all the way right or left. You should anticipate this by setting the aircraft into HDG mode with the heading bug set to the new, outbound radial's course. If you passed directly over the center of the VOR, you should end up right on the new radial -- otherwise, there may be a minor course correction once you get a few miles out and can establish where that radial is. Notice now that the TO/FROM flag should say FROM, and this time, your heading is the same as the radial heading, not the reciprocal. Again, if the course is close, pop the Autopilot back into NAV mode and it should get you right on it.

The number in the white box indicates the distance to the next station along the route. In this case it's 115 nautical miles. The best time to switch from navigating via the outbound radial of McComb and the inbound radial of the next station along the route is usually halfway; in this case, 57-58 miles after passing MCB. You can actually tune the next station on your NAV2 and watch until the two DME readings equalize; then make the switch. Again, temporarily use the Autopilot's HDG mode to keep the aircraft pointed on course while switching the NAV radios around. (If there's a segment on which you transition from outbound to inbound somewhere other than halfway, it's usually marked on the chart with a zigzag line, like two right-angles turned in opposite directions.)

Note that the inbound radial on the next station might not necessarily match the outbound radial on the current station. As you track out on the MCB 266, you would think this line would automatically become the 086 on the next westbound station, which is Alexandria (AEX). In fact it's the 085. Why is it a degree off, you might ask? Two factors cause this: curvature of the Earth, and magnetic deviation. Along some airway segments, the change in heading from one end of the leg to the next might be four or five degrees. Longer segments are more prone to this as well.

(INTERESTING TIDBIT: in the early 1990s I racked up hundreds of simulated flights and thousands of hours on a piece of software called Flight Assignment: Air Transport Pilot, which was a spin-off of sorts of the Microsoft Flight Simulator series, which at that point was still mostly focused on General Aviation. Rudimentary by today's standards of course, FA:ATP did feature reasonably realistic simulation of jet airliner flight with Air Traffic Control interaction and IFR procedures. In that era, inertia-based RNAV methods had long been abandoned for inaccuracy and GPS was still the exclusive domain of the military, so all navigation on commercial airline flights was done via radio navigation and VOR stations. As a result of this experience I sometimes think of modern flight automation as boring and too easy; of late, this has rekindled my passion for flying vintage planes and navigating purely by radio. You should give it a shot sometime -- it's not that hard!)

If you ever want to fly IFR between two airports that don't have a route in FlightAware or SimBrief, building your own route is a matter of (a) determining the optimal Jet or Victor Airways which connect the two locations, then (b) choosing the most appropriate SID and STAR to transition to and from the airway network; and finally (c) adjusting the result to ensure that restricted airspaces or other potential problem areas are avoided. Here's an example of a route I created from scratch (ironically, this route now appears in SimBrief, exactly as shown below):

I first decide that I would like to fly a LearJet 45 from Indianapolis, IN (KIND) to Atlantic City, NJ (KACY). (I imagine a group of business travelers headed to a conference and maybe to see a show and do a little gambling as well.) I note on FlightAware's IFR Route Analyzer that there are no recent real-world routes for this pairing.

My first goal is to find the main route or routes that connect KIND with KACY. I pull up SkyVector, click on the Flight Plan link to get the associated pop-up box, and enter in my origin and destination airports. I'll make sure I click over to the World Hi charts as well, since this will be a jet flight. This will yield a purple line which represents a completely direct path -- oh, if it were only that simple, LOL. However, I can see that there is a black line which seems to run parallel to my purple one, just north of it. Upon closer examination I find that this is the J110. This will form the bulk of my flight route today; now the question is one of locating the entry and exit points for that route.

So the next thing I want to do is check the departures out of KIND to see if there are any good ones that apply to turbojets headed eastbound. I head to the FAA Digital Terminal Procedures page (you can use AirNav or MyAirplane if you prefer) and punch in KIND. I see the following departures listed, and upon examining each one, I note as follows (note, some of these have been updated since I first wrote this section):

  • DAWNN EIGHT: southbound.
  • HOOSIER THREE: southwest-bound.
  • INDY SIX: is the generic vectored departure for KIND. This is our fallback if nothing else looks promising.
  • MAREO THREE: seems somewhat eastbound; ends at BDOCK. We'll keep this one in mind.
  • MEARZ THREE: looks more northbound.
  • ROCKY EIGHT: looks more northwest-bound.

So, either we'll take the MAREO3 BDOCK, or, we'll default to the INDY6 generic protocol which has the following eastbound gates: ROD, MIE, DQN, RID, SHB, and CVG.  I'm going to play with the route in SkyVector to see where all of these points are and figure out which one makes the most sense for getting near the J110.  I take a point a little ways down the J110, EMPTY, as my test-case, and enter BDOCK and EMPTY in my Flight Plan box.  I notice that the purple line is almost right on top of the J110 where BDOCK is -- that looks pretty good.  Now I'll change BDOCK to each of these other gates and see if any of the routes look as nice. In doing so, I see that ROD, MIE, and DQN seem to take me out of the way to the north, SHB and CVG take me too far out of the way to the south, and RID doesn't seem to do anything more for me than BDOCK does. So it's down to the INDY SIX to RID, or the MAREO THREE to BDOCK.  Since I feel like dedicated STAR routes are always preferable over generic vectored departures, we'll take the MAREO3 to BDOCK and then direct to EMPTY to join the J110.  As of now, my purple line goes from KIND via MAREO3 to BDOCK, then to EMPTY, then directly to KACY.

Next we need to find out how far to follow the J110, where to get out of it, and how to get the rest of the way to KACY. In looking at the arrival procedures for KACY I find that there are none. This makes things slightly more complicated, but, not much -- we just have to look at the Instrument Approach Protocols instead. What we're looking for is any VOR that serves as an entry point for that Approach. In pulling up all fifteen, I find that in seven of them, the ACY VOR station is the initial approach feeder point, or at least is one of them (VCN and SIE being the other two somewhat common ones). So it makes the most sense to end my route at ACY then to KACY -- although that sounds redundant, and an Air Traffic Controller will probably start vectoring me for the approach well before I get to the ACY VOR, I need something to navigate to in my flightplan. (A GPS could handle the last instruction being "direct KACY"; but, if you should ever be flying by radio, you would want the ACY VOR as part of the plan.)

So even though the change is negligible, I've added ACY as the last point in my route before KACY. Still, the plan is going direct there immediately after joining the J110 at EMPTY.  How far east do I follow the J110 until exiting it and heading to ACY VOR?  I zoom in and follow the jet route along to the eastern-most point that still makes sense to fly to without having to "backtrack," and enter it as the last point before ACY: PENSY.  By entering J110 in between there, SkyVector will know what this means, and will automatically import the points along the J110 between EMPTY and PENSY. This gives me KIND MAREO3 BDOCK EMPTY J110 PENSY ACY KACY.

So we know we're exiting J110 at PENSY, and somehow getting from there to ACY. The last piece to look at is that final direct leg, to see whether we can fly that direct or if we need to modify it any. Looking at the Enroute Lo chart, you'll see that the route passes through the Class B area at Philadelphia. Now, this is an IFR route, so this is not necessarily a bad thing per se. But, if you wanted to avoid that just to be sure you routed around any potential high-traffic areas, you could swing the route down to Smyrna (ENO) first. It looks like getting out of the J110 a little earlier than PENSY, at FLIRT instead, will make that much less radical of a turn.

This part of the route does pass from New York to Washington ARTCC but there don't seem to be any Jet or Victor airways close by that help us out in this matter, so, this should suffice. So that gives me my route as: KIND MAREO3 BDOCK EMPTY J110 FLIRT ENO ACY KACY.

 

 

Summary

Air Traffic Control strongly prefers pilots to fly realistic routes because it facilitates their ability to funnel large amounts of traffic in an organized manner, and to pass that traffic easily and efficiently to their virtual partners in neighboring sectors. The routes auto-generated by FS9 and FSX don't follow most real-world conventions so it's understandable that many pilots with lots of hours come to VATSIM and have a lack of understanding of ATC routing issues. Two great sources for realistic flight routes are FlightAware and SimBrief. It is also possible to create a route from scratch; the best advice is to stick to published airways (which in the US are mainly V, J, T, and Q-routes) as much as possible. SimBrief has a utility that will allow a route from any source to be transformed into a file that can be imported into the FS9/FSX default GPS; however, non-RNAV routes can also be flown purely by radio navigation using the NAV radios and HSI display.

 

DISCLAIMER: all information contained herein is for flight simulation purposes only.
revised October 2017

Click to listen highlighted text! Powered By GSpeech