Flight Training - June 2011 - 36

TECHNIQUE

INTERCEPTING A RADIAL
Think outside the box ALTHOUGH GPS IS the primary source of navigation for most pilots these days, it is important to also learn

» By Ian J. Twombly

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ILLUSTRATION BY CHARLES FLOYD
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PLUS See an intercept in action
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Flying an intercept

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1. Start on a known radial—Make sure the course deviation indicator is centered and showing either to or from the station correctly. 2. Select the desired radial—
Turn the omni-bearing selector (OBS) to the desired radial of intercept. For this exercise, it doesn’t matter where you are in relation to the VOR, although in a real-world scenario, you’ll likely only select a radial on the same hemisphere of the compass. After selecting the radial, the CDI will show the appropriate deflection.
36 / FLIGHTTRAINING.AOPA.ORG

3. Decide on the intercept—Now
comes the hard part. Since you already know generally where you are in reference to the station, deciding on the intercept involves nothing more than thinking about where the desired radial is in relation to your position (north, east, south, or west), and then deciding on a general direction to turn. Thinking about it from an inside-out reference, you’ll be turning toward the CDI needle. If it’s deflected left, you’ll turn left, et cetera.

4. Fly the intercept—Unless you are close to the desired radial or the VOR itself, it’s best to use a 45-degree intercept angle. Many heading indicators have small tick marks 45 degrees from straight up for this purpose. Simply put your desired radial on that 45-degree mark for the turn. When the CDI begins to center, turn to put that heading straight up on the heading indicator. When you do this depends on how far you are from the VOR and how fast you are going.

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STEP BY STEP

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the basic and advanced skills of VOR navigation. Many navigation principles are universal, and learning them on the VOR system will make you a better GPS pilot. One of the more difficult and advanced tasks to master with respect to VOR navigation is intercepting radials. The best way to complete the task is to think in terms of a bird’s-eye view and visualize the turns W 30 3 in respect to compass headings, not right or left. 3 First and most important is to make sure you have the correct VOR tuned. Enter the appropriate frequency in the navigationWradio, make it the active frequency, and then listen for the station’s Morse W 30 3 3 code identification. Compare this with what’s depicted on the sectional chart. Then it's time toWintercept. 1
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Flight Training - June 2011

Table of Contents for the Digital Edition of Flight Training - June 2011
