I have been doing a lot of reading into IFR navigation, and have been looking at the various instruments and systems that are used. I am going to exclude GPS here, as I have been focussing on some of the more 'old-school' methods.

My question is, if a private pilot decided to fly their GA aircraft from A to B, lets say a distance of 500nm, what IFR systems would they use to navigate?

My first answer myself would be VOR, but the range seems to be a limiting factor. For example, high altitude VORs have a maximum range of roughly 130nm (http://flighttraining.aopa.org/magazine/2000/December/200012_Features_The_ABCs_Of_VORs.html). If we were flying between two major cities, this wouldn't be an issue, as I would expect plenty of stations to track to on the way, but what if I was flying between two airports where the VOR stations were positioned 300nm apart? Is this sort of IFR navigation only possible with GPS?

Thanks in advance.


There are numerous options, and it depends highly on your route. But there are generally enough VORs scattered across the country such that you should be in range of a couple of them pretty much everywhere. As mentioned in another answer, there are NDBs, but in the continental US, generally, the ones not on an approach are getting fewer, as the FAA has followed a path of not repair them once they break. Other parts of the world, still use them and there are also NDB based airways(AIM has examples for how they can be charted on US charts).

If you had to plan a flight from a field that doesn't have a navigational fix, and you don't have GPS, you'd start by looking for airways near where you are. Once you find some that go in the general direction you want to go, you start figuring out intersections near that or how you plan to intercept the airway. Then you end up most likely planning a zig-zag course following airways towards your destination.


In the UK I generally use VORs where possible, then NDBs, then good old dead reckoning. GPS spoils the fun!... and besides the planes I regularly hire are at a flight school and each has a different GPS installed (or in one case no GPS at all). You "program" a VOR radio in pretty much the same way in all planes (or at least all of the ones I fly), but I reckon trying to remember what random combination of buttons, twists and presses I need to enter a route on each system is far more likely to end in a mistake.

For example to get from my local field to our nearest GA-friendly airport with an ILS is 2 VORs then an NDB (located at the ILS airport, and forms part of the procedural ILS).

I only use for dead reckoning for short legs, like getting through gaps in airspace around London - e.g. track outbound on from VOR to 8DME, then heading x for 7 minutes, then heading y until you intercept the z track onto an NDB]. I guess if you're in an area with very sparse VOR coverage you probably have less airspace issues, so less need for accuracy (terrain issues notwithstanding - but the higher you are the further the reception). In that case longer-distance dead-reckoning may get you between VORs.

I also have an app on my iphone which warns if I'm about to bust controlled airspace, but that breaches your "no GPS" question :).

Technically you can use "VDF" too in the UK (i.e. some airports can tell you your bearing from radio transmissions), although I've not tried that myself.

  • 2
    $\begingroup$ How do you file a flightplan for dead reckoning? That sounds counter-intuitive for IFR.... $\endgroup$ – SentryRaven Oct 16 '15 at 7:53
  • 1
    $\begingroup$ Just out of interest, whats that app called? $\endgroup$ – Matt Kelly Oct 16 '15 at 8:36
  • $\begingroup$ @phil I'm not sure your proposed edit is needed. I believe you can always comment on your own posts (I'm open to persuasion otherwise...) $\endgroup$ – user11516 Oct 17 '15 at 9:52
  • $\begingroup$ @MotherGrinningBird Thanks, it was user incompetence on my part, somehow I created two logins and tried to comment with the other. $\endgroup$ – Phil Oct 19 '15 at 21:17
  • 2
    $\begingroup$ @MattKelly It's the Aware app (itunes.apple.com/gb/app/airspace-aware/id522037116) $\endgroup$ – Phil Oct 19 '15 at 21:19

You can use Automatic Direction Finder (ADF) along with Non Directional Beacon (NDB).

Of course, VOR/DME, GPS/GNSS and radar (by ATC) can also be used.

  • $\begingroup$ Thanks for replying. I have found ADF to have a very limited range, much more so than VOR. It seems to be more useful as an aid during an ILS approach, if not as a non precision approach itself. $\endgroup$ – Matt Kelly Oct 15 '15 at 23:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.