Some of a pilot’s favorite words are heard on the ATIS: “Winds, Calm.” These words set off all sorts of happy bells and hallelujah choruses. Most pilots spend their lives fighting the winds. On those rare days when the winds are calm, great happiness ensues.
But, are calm wind landings more complicated then everyone thinks? Well, they can be if the proper planning doesn’t go into them.
Let’s think about wind. We have surface wind and we have winds aloft. Sometimes the surface winds are calm. When this happens, certain airports have preferred calm wind runways which are supposed to be used in these conditions. Winds aloft are almost never calm. 95% of the time, there is some kind of wind even 100-200 feet above the surface.
Here is the question pilot’s face when coming into an airport with calm winds: which runway do I use? Do I use the calm wind runway? Do I use the runway that is easiest to enter the pattern for? Do I use the one with the shortest taxi?
A lot of technologically advanced aircraft have a wind indicator on the PFD. This tool is often forgotten in calm surface wind conditions. On the contrary, this is probably the most important tool a pilot can have when figuring out which runway to use when the winds are reported calm.
Here’s why. That wind indicator is showing the pilot what the winds aloft are. The winds aloft should determine what runway is going to be used. If the wind indicator is depicting a south wind, then a south runway should be used. Even if it is a 5 knot wind at pattern altitude, it’ll still be a headwind coming in on final approach. If the north facing runway is used, that same 5 knot headwind can blow an airplane halfway down the runway before the ground speed drops off enough for it to land.
So, the next time you are coming into an airport and the winds are reported calm, take a look at your wind indicator on your PFD when deciding which runway to use. It’ll probably save a few go arounds!
I remember this one well! 5 go arounds!
Lesson well learned, no harm just a little ego bruising