# What's a quick way to determine which runway to use?

guidoism
• What's a quick way to determine which runway to use? guidoism

Let's say I call up Wx and have the wind direction and I know the runway headings from my charts and the pattern is empty. I can do the math, but it's tedious and slow and even worse when there are multiple runways. This is what I usually do:

• Runways are 13 and 31
• Wind is 253° which rounds to 25
• $25-13=12$
• $31-25=6$
• I'm going to use Runway 31

Is there a trick to determine best runway quickly without doing the math?

• In uncontrolled airports I've avoided problems simply by asking on CTAF which runway is in use when 10-7SM out. This has worked out well because often times there are aircraft in the pattern on the wrong runway (from the perspective of crosswind) because conditions changed and traffic has been busy, or someone is just doing their own thing.

I've even had a unicom station respond with a recommendation when nobody in the air responded. It doesn't hurt to ask and if you get no response a quick glance at the heading indicator can save you the math by just visualizing the runways over the indicator and choosing the one that's closest to the wind.

• Is there a trick to determine best runway quickly without doing the math?

Aside from "Asking the other pilots in the pattern / UNICOM", none I'm aware of.
The closest thing to a "trick" I can offer you if you're going in to a completely unattended field are the following suggestions:

Now find the runway alignment closest to the bug. That's the runway you want.
(If your DG doesn't have a heading bug you may still be able to do this visually easier than doing math - of course this relies on you flying in a plane with a DG or a vertical card compass...).

2. Break out your E6B, dial in the wind direction, and find the closest runway heading.
Same logic as (1), but for when you're stuck in a Piper Cub with only the wet compass.
One drawback - it only works with mechanical flight computers...

3. If you have your sectional out, lay your pen or ruler on it to show the wind direction.
See which runway alignment is closest to the ruler. That's the runway you want.

(Seriously, this is what I do most of the time. I'm an engineer, I can't add and subtract!)

• This might take a few seconds longer, but it's math-free: On your kneeboard, draw a quadrant (like this: +). Draw a line through it for your runway(s). Draw an arrow to represent the wind. The answer will be apparent. Do it enough times, and you'll be able to visualize the drawing without actually doing it.

It's also a great technique for calculating holds.

• When I arrive at an uncontrolled airport, and there's nobody there to tell me what everybody else is doing, I overfly the airport to get the lay of the land and to look at the wind sock. This should be SOP for everybody.

Once glance at the wind sock will tell you which runway the winds favor. No math or diagrams required.

You should also be looking for a tetrahedron. This will also give you information about the pattern.

Nominally, this is the authoritative answer about landing direction, but I've known airports where the tetrahedron was inoperative. If the wind is strong and the wind sock contradicts the tetrahedron, consider trusting the wind sock instead. Or better yet, consult the locals.

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• Let's say I call up Wx and have the wind direction and I know the runway headings from my charts and the pattern is empty. I can do the math, but it's tedious and slow and even worse when there are multiple runways. This is what I usually do: Runways are 13 and 31 Wind is 253° which rounds to 25 $25-13=12$ $31-25=6$ I'm going to use Runway 31 Is there a trick to determine best runway quickly without doing the math?

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