A pilot working on his instrument rating asked if it would be better to carefully plan a route or simply file direct. Some of his buddies recommended researching the route and filing via airways, while others suggested just filing direct and being done with it. Of course, for instrument students, the best resource is your instructor, but let us put this question into perspective.
We now live in a world where it’s simple to navigate directly to any point on Earth. As recently as about 25 years ago, there was no question because there was no simple way to navigate distances direct. (VOR/DME-based RNAV filing was certainly a fun exercise though.)
One similarity remains. You’re not likely to get what you file through busy airspace. It’s been a rite of passage for instrument students to painstakingly plan a route by hand, only to have ATC issue a completely different route. We thought of that as an initiation into real-world IFR flying.
But these days we have tools that give us insight into expected routes. Yet somehow it’s become popular to just skip route research and file direct, knowing ATC will sort it out for you. Let’s examine why this is a bad idea, and provide some ways that pilots can file routes that they’re likely to actually receive.
Let’s Just File Direct
I’m undecided as to whether the file-direct school indicates an optimistic or pessimistic thought process. On one hand, we have these great navigational capabilities, so maybe this time the controller might actually give us a direct route across a major metropolitan airport’s arrival corridor. On the other hand, who knows what route the controller is going to come up with this time? Since we have no way of knowing, we’ll just give up and fly whatever they tell us. It really doesn’t matter, since in instrument flying you must simply be a realist.
Filing a simple direct route is technically contrary to AIM 5-1-8(d), which states that operators should “[f]ile a minimum of one route description waypoint for each ARTCC through whose area the random route will be flown. These waypoints must be located within 200 NM of the preceding center’s boundary.” Do many (any?) pilots adhere to this? Probably not, but it’s unlikely that it’s in there because the FAA needed to fill up extra space. (See “Go Direct, Fix by Fix” in the July 2012 issue for a simple way to meet this requirement when filing direct.)
Don’t get me wrong; there’s nothing inherently incorrect with direct routes. They’re great and I’ll certainly take one whenever it’s offered. Sometimes filing a direct route is appropriate, such as on short-distance flights or when your research indicates that a direct route at a given altitude is both safe and likely to be provided as your clearance. The problem arises when pilots make it a habit of only filing direct routes, regardless of whether receiving a clearance for such a route is at all realistic. Filing direct between Washington DC and New York? Good luck.
Responsible Route Filing
Say a pilot does just this. He files direct, resolved to just fly whatever the magic ATC computer directs him. He fires up the engine and calls for his clearance, and (no surprise) copies down a full-route clearance, which he dutifully loads into his navigator without review. This has effectively off-loaded his flight planning responsibilities onto some poor guy at the local TRACON.
A flight along airways obviously covers a greater distance than a direct route—sometimes a significantly greater distance. Does the pilot have enough fuel to fly the new route? How’s the weather along the route? Are there any TFRs that the pilot didn’t notice when he traced a straight line to the destination airport (or imagined one)? Will his filed altitude be sufficient along the new route? The reality is that any flight planning the pilot did before is probably no longer valid, and the TRACON guy doesn’t know the answers.
Another problem with this type of flight planning is that you might occasionally get direct as your clearance, but that can be a mixed blessing. Since individual ATC facilities don’t always see the big picture, you might receive a direct clearance initially, only to be given a reroute once you’re airborne. If you’re exceptionally unlucky, each ATC facility will revise previously issued reroutes, requiring you to copy several updated clearances. This is particularly the case when departing a small town on a route that will transit busy airspace along the way. When this happens, you’ve got to cope with the distraction of copying and loading a new route, while considering the flight planning questions discussed above.
A few years back, I used to fly airplanes for a living that didn’t have GPS. It seemed like every day we would be given direct to a fix, and would have to respond “unable direct, we’re slant alpha.” While flying those airplanes, I honestly had the best positional awareness that I’ve ever had. Flying airways, identifying fixes by DME or cross radials, and frequently checking an enroute chart gives you a level of situational awareness that you don’t get from a magenta line and a destination that’s a few hundred miles off the nose. In later years, and with a fancier avionics stack, I’d sometimes not even know what state I was over without a little research.
I’m a realist, and certainly recognize the value that GPS-based navigation provides. However, there is some level of situational awareness that is lost when flying a direct route rather than a route along airways. In addition, for lower-performance aircraft, the MEAs along airways are usually lower than the MORAs, which can give you some added wiggle room if needed.
File What You’ll Actually Get
The just-file-direct approach to route filing was born out of misguided pragmatism. For all practical purposes, the modern ATC system is a black box. The ATC-cleared route between two airports is rarely intuitive, and may vary for any number of reasons, such as time of day, altitude, or large-scale traffic flow patterns (a result of traffic density, weather, etc.). Why bother figuring out a route, when it has no bearing on what the ATC black box is going to issue for you? Short of personal experience or asking around in the pilot’s lounge, historically there hasn’t been a way to figure out likely ATC routes in advance. That’s changed.
For several years, flight-planning tools such as FlightAware, Fltplan.com, Garmin Pilot and others have provided pilots with route suggestions based upon historic flight-plan data. This enables pilots to gain insight into the ATC black box and file routes based on what other pilots have actually received. It’s not always an exact science, but it takes a lot of guesswork out of route planning. Plus, it mitigates the file-direct arguments.
What about those times when you’re flying from Podunk to Nowhere and there’s no data on previous ATC routes? Try looking at routes between nearby airports instead. Although the differences mean you’ll be less likely to get “as filed,” you’ll hopefully see the preferred routing for at least the enroute portion of your flight.
It’s rare to plan a route with no previously-cleared routes for guidance. When you’re a route pathfinder, go ahead and plan a realistic route considering busy airspace. You might even get lucky.
It can also be helpful to use a two-fix route strategy. By filing a fix near the origin airport and a fix near the destination airport, you’ll give ATC at least something to work with. In either case, the route you receive will make route data available for future pilots.
Although they don’t take the place of your official clearance, FlightAware, Fltplan.com, and ForeFlight can send you email notifications of the route that you can expect in your clearance, once your flight plan has been filed. This is a great way to ensure that your flight plan has made its way into the system and avoid that sinking feeling you get when ATC tells you “no plan on file” when you’re at the end of the runway. Also, since you would typically receive the notifications prior to starting engines, it gives you a chance to look over any changes to your route and ensure that your flight planning is still valid.
It’s Just Part of the Job
Using today’s available flight planning tools, it doesn’t take long to figure out the route that you are likely to actually receive. For a typical flight, it seems to take about five minutes to research, brief, and file a realistic route. It’s not difficult, so there’s no need to obsess or stress (“obstress”?) over the route, but don’t neglect it, either. Since historic route data is freely available now, there’s really no justification for not referencing it, other than sheer laziness.
The fact remains that the ATC black box is going to give you what it needs. However, by being prepared, you’re able to perform more accurate flight planning and be more situationally aware before and during the flight. You can’t possibly anticipate everything that will happen during a flight, so there are always plenty of questions that will need to be addressed. It’s worth an extra few minutes before a flight to have the peace of mind of not unnecessarily adding to those unanswered questions.
More than that, performing the best possible flight planning is what you owe to yourself and your passengers. An essential part of flying professionally is to not take shortcuts—except, of course, when they’re offered by ATC. Go ahead and take those.
Lee Smith, ATP, CFII, is based in Maryland and expects to hear “cleared as filed” and “direct, when able.” (He also believes in Santa Claus.)
