How VORs Really Work

Flight instructors across the nation have been involved in a massive coverup scheme surrounding VOR stations. We’ve all been taught to think of VOR stations as a giant compass rose transmitting radio beams in 360 directions. It is common to refer to a VOR as a giant wheel with 360 spokes representing radials. These are all lies. 


Well, not exactly. All conspiracy theories aside, flight instructors have been telling this story for a good reason, it is much easier for pilots to conceptualize a great spoked wheel in the sky than to understand the inner workings of the machine.

It’s the age-old “black-box” argument. It is far more important to be able to use a VOR than to know how it works. That being said, a VOR is a surprisingly simple device.

VOR stations are nothing more than the radio equivalent of a rotating beacon with a flashing strobe. To conceptualize the system, consider the following simplification:

The omnidirectional signal pulses as the unidirectional signal passes north.

The omnidirectional signal pulses as the unidirectional signal passes north.

Each VOR consists of  red unidirectional rotating beacon and a white omnidirectional strobe. The rotating beacon turns at a rate of one degree per second, so that it makes one complete rotation every 360 seconds. Every time the beacon passes through north, the strobe flashes white.

By comparing the time between beacon and strobe flashes, the airplane’s onboard equipment can determine the current radial. For example, if it you were to see a white flash followed by a red beacon 45 seconds later, then you would be on the 45 degree radial from the station.

The VOR system works in exactly this way, except that it uses unidirectional and omnidirectional radio signals instead of beacons and stobes. For accuracy, the unidirectional signal, our “beacon,” rotates at a dizzying 1,800 r.p.m.

Helpful Links:
VOR / ADF Navigation Simulator
Wikipedia’s Article on VORs


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About the author
Pat Flannigan is a professional pilot, aviation blogger and licensed flight instructor. He has been flying for fourteen years and is currently working as an airline pilot in the United States.

5 Replies to How VORs Really Work

  1. Paul says:

    Thanks for the very informative article. I learn something new everytime I visit your site. Keep up the good work, it looks GREAT!

  2. Very neat explanation. Although one doesn’t need to know the details it certainly is quite interesting.
    Thanks for the article.

  3. Can you add my blog to your list? I certainly would appreciate it.

    W. Erston

  4. I am a serious Flight Simulator pilot and I have really worked hard to learn all about the Nav Aids-VORs, NDBs Inter sections etc., given out in the respective programmes’ Learning Centers as a beginner in the FS world and was not satisfied at all just by learnig to fly the FS planes. I believed the the articles written about the VORs and their functioning and usefulness in those lessions.
    This article of yours about the VORs and how they actually function is a wonderful nice thing. Now it is a very easy to understand and grasp the essence of VORs working,Sir. Now I feel that I am a truely better enlightned FS pilot than what I was before. ( I have taken the Private Pilot Certificate, Commercial Pilot Certificate, Instrument Flight Rating Certificate and the Airline Transport Pilot Certicate in a quite popular FS programme which I loved and still love a lt.) I am really lucky to have stumbled on this nice article of yours.
    Thanks,
    M.S.Murugesan.

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