CyberAirVA

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DME ARC

In some approach charts or STAR charts you will find what is called an ARC. This is a usually a part of a circle around a VOR beacon. It serves as a way to approach the airport and usually ends up on the desired runway for landing. I made a small illustration below. In this case we are going to land on runway 36 and we will fly an ARC approach to get there. We start out on a heading of 090 degrees inbound to ARS VOR beacon (112.80). When our DME tells us we have 11 nm left to ARS VOR we start a left turn to a new heading of 010 degrees, at the same time we turn our VOR receiver to radial 290. We then waits for the needle in our VOR receiver to indicate that we are passing the 290 radial. Now we turn our plane 10 degrees to the right, i.e. a new heading of 020 degrees. After completing this we also turn the VOR receiver 10 degrees to the right, i.e. the 300 radial. We then repeat this procedure, i.e. turn the aircraft 10 degrees, turn the VOR receiver ten degrees, until passing the 180 radial, when we turn right onto the final for runway 36.

We should be about 10 nm away from the VOR we are using (since it's a D10 ARC). If we are a bit to close, we simple turn less than 10 degrees when it's time to turn, note that we always turn the VOR receiver 10 degrees though. If we are a bit to far away we correct this by turning more than 10 degrees. Usually ATC won't react until we are about 5 nm's of the arc. As with everything else it takes a bit of practice to perfect the arc, if you find it to hard, you can use 20 degree intervals instead of 10. Remember that if you are going to fly an arc counterclockwise turn the aircraft and receiver to the left.

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