A Beginners Guide to Navigation
By John Hefcheck
In January of 1997 I purchased Microsoft Flight Simulator For Windows 95. I was really looking forward to doing some flying. I didn't know very much about flying and never really thought about how a pilot found his way from one airport to another. I loaded up FS95, read enough of the help file to figure out how to get started, and commenced with my first flight.
My first flight turned out to be a VFR trip around Meigs Airport. Now I was ready to do some real flying! I looked at the sectional charts in the FS95 manual and realized that there were no instructions on how to get from one airport to another. I became very discouraged and gave up on FS95. About 6 months later, I read the book "Airframe" by Michael Crichton and that gave me the bug to try flightsimming once again.
Needless to say my frustration was back! I was about to give up again when, out of desperation, I turned to the Internet. After a lot of searching around, I felt I was getting nowhere fast. Then it happened! I somehow stumbled upon FlightSim.Com where I found the help I needed to be able to fly.
So now I would like to "give back" a little by helping out with what was for me (and probably you, if you are reading this) a major stumbling block. Oh well, enough background already, let's get ready to navigate.
To successfully get from your starting airport to your destination you will need a set of directions. This set of directions is known as a "flight plan". Real aviation pilots have to purchase charts which help them map out their flight plan. As a simmer you could get a set of these charts and develop your own flight plan, but it is costly and is really unnecessary. There are several freeware flight planning programs available right here in the file library at FlightSim.Com that can do the job.
For this tutorial I use the program Nav 1.8, a freeware flight planner created by Ted Wright. I highly recommend that you download and use this program. Once installed Nav 1.8 will scan your scenery directory and create a map with all of the airports, VOR's, NDB's, ILS's & ATIS's that are in your scenery. It also supplies a wealth of information about your scenery.
For this example we will fly from "Wings Field" in eastern Pennsylvania to "Robert J. Miller Air Park" in New Jersey. In Photo 1 below, you will see the flight plan I created for this flight using Nav 1.8.
Let me give you the basic rundown on how to use this flight plan. Locate Wings Field on the flight plan, which will be our departing airport. Then locate Robert J. Miller Air Park, which is our destination airport. If you look at the flight plan you will see a line that starts at Wings Field and continues through two blue circles and terminates at Robert J. Miller Air Park. This is the path we will be flying.
The blue circles that you see are VOR's. A VOR works by sending out radio signals that can be received by our NAV radio in the airplane. These signals start in the center of the VOR and radiate outward away from it. There are 360 of these signals spaced 1 degree apart. (There are 360 degrees in a circle).It is very similar to the spokes in a wheel. These "radiating spokes" are called Radials. The 0 degree radial always faces Magnetic North. (Magnetic North is a few degrees off from True North). The VOR in the flight plan has a line radiating from its center toward Magnetic North, so you can get an idea where 0 degrees Magnetic North is located.
Back to our flight plan for a minute. If you are at Wings Field and want to fly to the first VOR (North Philadelphia PNE) you would need to leave Wings Field and head toward the PNE VOR at 115 degrees magnetic. You find this information on the flight plan. Note how over the flight path line you can see the designation 5.9nm@115. This tells you that you need to fly away from Wings Field at a heading of 115 degrees for 5.9 nautical miles. At this point you should be at the top of your climb. Now you will see the designation 6.4nm@115. This means that we need to fly an additional 6.4 nautical miles at 115 degrees to reach the PNE VOR. Take note that even though you are approaching the PNE VOR at 295 degrees relative to the center of that VOR, you are going to be flying the radial that originates from the center of the departing VOR. Some people seem to be a little confused about this, but it's really pretty easy. Your heading is always relative to the VOR (or airport) from which you left.
After you reach the first VOR you will need to change your heading to 113 degrees. This is because you need to travel on the 113 degree radial FROM the PNE VOR in order to reach the GXU VOR.
Now let's take a look at the airport layout below in Photo 2. As you can see, we will be taking off from Runway 6.
Look again at the airport layout. The top of the picture is North (0 degrees), the bottom of the picture is South (180 degrees), the right side is East (90 degrees) and the left side is West (270 degrees). Notice that by taking off from Runway 6 you are headed North/East at 60 degrees. That is why the runway is named Runway 6. If you take the runway angle (60) and divide by 10 you get 6. If you took off from the other end of the runway, you would be heading South/West at a heading of 240 degrees, hence the name of the runway would be Runway 24 (240 divided by 10=24). So every runway has two names. One at each end depending on which way you are taking off or landing. Also notice that the Runway numbers are 180 degrees opposite from one another. (Runway 6 is 60 degrees + 180 degrees=240 degrees, and 240/10=24).
Okay now let's get flying. Fire up FS98 (I am using FS98 and although the principles of navigation are the same, the airports I am using may not be part of your scenery if you are using a different version of FS). On the start up screen choose "Create Flight". Choose the "Cessna 182S" for your airplane, then choose "Wings Field, Runway 6" as your starting airport. Choose "daytime" as your time of day and leave the weather option alone.
Hopefully you are now sitting at Wings Field on Runway 6. Let's take a look at our flight plan. As we discussed previously, we need to fly away from the airport 5.9 nm (nautical miles) at a heading of 115 degrees at which point we should be at the top of our climb (for this flight we'll make that 4500 feet). Then we will continue for an additional 6.4 nm at a heading of 115 degrees at which point we should be reaching the VOR named North Philadelphia (PNE). Notice our flight plan tells us that in order to receive the signal from the PNE VOR, we need to have our NAV radio tuned to 112.00.
After reaching PNE, you will see that we need to fly 19.5 nm at a heading of 113 degrees to reach the McGuire VOR (GXU). Notice that the NAV radio needs to be set to 110.60 in order to receive the signal from that VOR. After reaching the GXU VOR you'll see it's just another 11 nm at a heading of 121 degrees until we get to Robert J. Miller Air Park.
Now we'll get our plane's instruments set up for the flight. First we'll set the NAV1 radio to 112.00 so we can receive the PNE VOR. To do this you will need to pop up the radio stack. Press the big white avionics button at the bottom of the panel. The top radio is the NAV1 radio. To set the frequency place your mouse cursor over the numbers. When your cursor turns into a hand you'll see either a + or - sign. While it's a + sign, click to make the numbers increase and when it's a - sign click to make the numbers decrease.
Next we need to set the Omni-Bearing Indicator (OBI) to the heading we want to be flying. That would be (115 degrees) to reach our first VOR. To do this, click the white avionics button to hide the radio stack. The OBI is the ring of numbers that go around the VOR Indicators. We want to set the OBI on the VOR 1 indicator. See Photo 3 below to identify the VOR 1 indicator. Now place your cursor over the OBS button. When the cursor turns into a hand with a + sign in it, start clicking. See how the ring around the dial rotates? Stop clicking when 115 is at the top of the gauge. (Note 115 is just a little before 12 (120) on the dial).
At this point let's plan ahead a little and get set up for the GXU VOR. Pop up the radio stack again. The second radio down from the top is the NAV2 radio. Set the frequency to 110.60. Now click the white avionics button and hide the stack. Set the OBI on the VOR 2 indicator to 113.
Take a look at the Photo 3 again to see how your panel should look. (Notice that I have slightly modified my panel to make it easier to read the DME) (distance measuring equipment)). If your panel is set up like mine you're ready to take off. (Don't forget to set your flaps!)
Well it's time to take off. You are now flying away from the airport at a heading of 60 degrees. We need to turn right so we can track the 115 degree radial to the PNE VOR. Take a look at the Wings Field airport layout. You'll see a red line showing the approximate path you need to take to get onto the 115 radial. Notice you need to turn further than 115 degrees to intercept the 115 radial. Once your altitude reaches about 1500 feet you'll see your VOR indicators come to life. Since the signal radiates in a cone shape from the center of the VOR transmitter, you can see why you need to get some altitude before you begin to receive the signal.
Now take notice of the vertical white needle that pivots from the top or the VOR 1 Indicator gauge. This is the Course Deviation Indicator (CDI). This needle tells you if you are to the right or to the left of the desired radial. (In our case the 115 radial). You always want to fly toward the needle. When the needle is centered (straight up and down) that means you are tracking the radial correctly. See the picture below, Photo 4 and notice that the CDI needle in my VOR 1 indicator gauge is to the right of center. Also take note that my heading is about 150 degrees. As the CDI needle begins to move toward the center I'll start to turn left. Ideally I'll be back to 115 degrees just as the needle centers, but a lot of times you will over-compensate and the needle will go past center and start to swing in the opposite direction. You will then have to turn back again until the needle starts to center. After flying for a little while you'll get the hang of how far past your desired heading you'll need to turn in order to smoothly intercept your radial. You normally will not need to go more than about 30 degrees past your desired heading to intercept your radial. Remember if you turn too sharply you'll just cross the radial, and if you turn too shallow you'll never reach it. Also notice that the closer you get to the VOR the more sensitive your needle will get. As you get close don't go crazy "chasing" the needle, just try to stay close to your heading.
Some VOR's also have "Distance Measuring Equipment" (DME). The PNE VOR does not have this, but as we'll see a little later the GXU VOR does. Take note of where my cursor is in Photo 4. That little knob between the "N1" and "N2" tells which Nav radio the DME distance readout is indicating. Again in Photo 4 above, you can see it is set for NAV1. Now take a look at the VOR 1 indicator. Take notice of the little triangle just above the 30. See how it is pointing upward? This flag indicates the airplane's position in relation to a line perpendicular to the selected course and passing through the VOR. In simpler terms, if it is pointing up and you are flying roughly on the heading set by the OBI you are flying toward the VOR and conversely if the flag is pointing down and you are flying on the heading by the OBI you are flying away from the VOR. This flag is known as the "to-from" flag or "ambiguity indicator".
Pretty soon you'll see your CDI needle starts swinging all the way to one side and shortly after that the ambiguity indicator will be pointing downward. This means you have just passed the PNE VOR. Now it's time to change our heading to 113 and start using the VOR 2 Indicator. Also, let's click that little knob in the DME readout to N2. You should now see a reading of how far you are from the GXU VOR. You can watch the distance count down to zero at which point you will have reached the GXU VOR.
In the Photo 5 below, you can see that I am between the two VOR's. The VOR 1 Ambiguity Indicator is pointing down (traveling away from the PNE VOR) and the Ambiguity Indicator for VOR 2 is pointing up (traveling toward the GXU VOR). Also see how I changed the knob on the DME gauge to the N2 position. You can now see that I am 13.4 nm away from the GXU VOR.
Once we reach GXU it will only be 11 nm from the airport, so it's time to plan ahead again. We are going to be landing using the Instrument Landing System (ILS) so we now have to set up our NAV 1 radio and our VOR 1 Indicator.
We will be landing on Runway 6 at Robert J. Miller Air Park. Unlike a VOR, when tracking to an ILS it is not necessary to set the OBI to the desired heading, however it's handy to do so as a reminder of what heading you want to fly. So for this landing adjust the OBI on VOR 1 to 60 degrees. Now we need to pop up the radio stack and set the NAV1 radio to the ILS frequency, which in this case is 109.9. (The ILS frequency is the number in the red rectangle on the flight plan.)
When we pass GXU (and we'll know because the needle will swing wide and the Ambiguity Indicator will be pointing down) we will change the OBI on VOR 2 to 121 degrees. We can also watch the DME count up the miles. As we get close to the airport the needles on VOR 1 will jump to life. And yes you read right, that word was needles. There are now two of them. The vertical needle still works the same, but now we have a horizontal needle that pivots on the side. This needle is the "glideslope indicator". This will tell you if you are too high or too low on your approach. Once again you will need to fly toward the needle. If the needle is above center you are too low and if the needle is below center, you are too high. So all you need to do is to get both needles centered and you'll land right on the runway. Photo 7 below shows me getting lined up for my landing. Note how both of my needles are centered.
With a little practice you'll be navigating like a pro. One other thing I wanted to mention was "Non-Directional Beacons" (NDB). The NDB receiver in a modern airplane is known as an ADF (automatic direction finder) an on our panel is the gauge just to the right of VOR 1. I didn't cover them so I'll give you a quick rundown on there use.
You set the NDB frequency in the third radio from the top. The NDB works a lot like a VOR except it's non-directional. The needle on the ADF gauge always points toward the NDB. If your needle is pointing to the right, it means that the NDB is to the right of your present position. To reach a NDB you want to position your plane so the arrow on the ADF gauge is pointing straight up. When it points straight up, you are headed straight at it. When the needle starts pointing down you passed it.
A couple of final thoughts about VOR's. There may be times you will pass one VOR and be headed toward the next, but you won't be getting a reading on your VOR Indicator. This means that you are out of the range of the VOR. You'll know you're not getting a reading when your needle is straight up and down and your Ambiguity Indicator is missing. In that case just adjust the OBI of the VOR you are flying away from and track away from the VOR you just passed at your new heading. Eventually you will pick up the signal from the VOR you are approaching.
Also be sure to download and install the MS Converter even if you don't plan on using any 3rd party planes. The converter includes among other things a patch for the VOR ranges. Without this patch many of the VOR's ranges are far to short.
I hope this helps get you up and flying. Keep practicing, it's really not that hard. Hope to see you on FlightSim.Com.