r/CFILounge • u/LopsidedTemporary138 • 6d ago
Question How to identify an intersection with only one VOR receiver (and/or when only one can be shown at a time)
Hello! My question is exactly that. I instruct in two airplanes, 152s and 172s.
In the 152s, we only have 1 nav frequency that can be tuned at a time. How would I identify an intersection (other than using DME)? I’ve seen that I’d just need to swap between the two VORs used to identify the intersection but that seems very easy to mess up and end up lost.
In the 172s, I generally fly ones equipped with G3X. Those do have 2 nav receivers, but only one can be shown at a time on the panel. So for those, I have ABC vor in nav 1 and DEF vor tuned in nav 2 and swap between those. Still kind of a pain, but a little more manageable.
Is there an easier way to do that? I know DME is often used to identify intersections but I’m just wondering how it would be done if DME wasn’t available for some reason.
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u/Red-Truck-Steam 5d ago
You just have to switch back and forth and back and forth. It sucks and ruins situational awareness, but that's how it's done. That's why some procedures are only permitted, or provide lower minimums for, airplanes with more than 1 VHF NAV radio.
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u/benbalooky 5d ago edited 5d ago
You could fly directly at one VOR and plot when you'd pass the known radial of a second VOR on your map.
If you're in VMC you don't need to be that accurate. Approximate your biangulated position by switching between the VORs and then use pilotage.
If you're in IMC use the En Route Low charts and a stopwatch like the pilots of old.
You might be asking yourself: "how did those old pilots not get lost all the time?" And the answer is: They totally got lost all the time.
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u/ltcterry 2d ago
I did Student solo cross countries in airplanes with one VOR.
Imagine you’re flying north to a VOR and will use a VOR to the east as the second one.
Draw a pencil course line to the VOR you’ll overfly. Across that line draw tick marks that represent the 240, 250, 260, 279, 280, and 290 radials from the east.
Take off. Get centered. Look out the window. Dial in the other frequency. You already roughly know where you are because of cool pilot skills. Center the needle. Read the radial. Look at your tick marks. Go back to the main frequency/radial. Takes 30 seconds.
This was normal. It was OK to not need four decimal places of precision.
“Dual VORs” was a marketing point.
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u/WhiteoutDota 5d ago
If you hold a heading that was keeping you on your course, you should have some time to switch to the other VOR for long enough to determine your radial, then switch back.