• How To... Navigate Using A VOR

    NAVIGATE USING A VOR

    by Nels Anderson

    Using a VOR to navigate is a basic pilot skill. Though you only rely 100% on radio navaids when flying IFR, even the basic private pilot certificate which allows only visual flying requires that you know basic VOR navigation techniques.

    As a flight simulator pilot you can make good use of VORs too, whether flying VFR or flying completely on instruments. Even the relatively simple maps that come with the Microsoft sims show VORs so you can start using VOR navigation with nothing more than the basic FS5, FSFW95 or FS98. More advanced pilots will want to use real world charts especially when flying outside the default scenery areas.

    Figure 1
    VOR transmitter
    Figure 2
    On FAA sectional charts a VOR is indicated by a blue circle marked with compass points to indicate its radials

    It's not as hard as it may seem to the newcomer either. First, it helps to understand what exactly a VOR is. It's a ground based navaid, transmitting VHF (very high frequency) signals in all directions (See Figure 1). VORs transmit on frequencies between 108.0 and 118.0 MHz.

    A VOR transmits "radials" that are one degree apart (See Figure 2). By selecting the radial of interest using the radios in your airplane you can not only navigate to and from the VOR station you can do it on a specific course.

    Navigating directly to a VOR is the easiest way to use this kind of navaid. You can do this with just a couple of steps (note that how exactly you accomplish these steps depends on the sim you are using; we won't cover that here):

    • Dial in the frequency of the VOR into your NAV1 radio
    • Turn the OBS for OBI 1 until you see the word "TO" and the CDI needle centers
    • Note the heading shown at the top of the OBI; fly that course to go directly to the VOR
    That's basically all there is to it! Now, in the real world there are complications such as crosswinds that will affect your ability to get to the VOR. If you have winds you will have to adjust for them and fly a heading that will allow you to follow the proper course.
    DEFINITIONS:
    • Heading: the compass direction where the nose of the plane is pointed
    • Course: the track along the ground that the plane is actually flying

    In an ideal situation you could fly the heading you just determined right to the VOR station. In that case the needle on the OBI would remain centered right up until the time when you passed over the VOR. More likely, though, your course will drift off to the side. By watching the needle on the OBI you can see this happen and also tell how to adjust your heading to get back on course:

    Figure 3
    If your OBI needle looks like this when you are trying to follow a course of 280 degrees toward the VOR, you need to adjust your heading to the left
    Figure 4
    If your OBI needle looks like this you need to adjust your heading to the right
    Shown is a typical OBI gauge; the exact look of the gauge will vary with the sim and panel being used.

    The adjustments you make should be small. Start with around 10 degrees. For example, if your desired course is 280 degrees and the needle is off to the right then turn right to a heading of about 290 degrees. If the needle starts to swing back towards the center you have enough adjustment. If it continues to swing away from the center turn right a bit more. Flying using VORs is a matter of constantly making small adjustments like this.

    Now, let's continue with a short example trip.