When a plane comes into an airport to land, they will attempt to land on the runway which is best aligned with the wind This means that when landing, pilots attempt to land “into the wind” as much as possible This gives the plane the greatest amount of airflow over the wings, and therefore greater lift, without an increase in speed.
Before landing, pilots obtain weather information, either from ATIS (automatic terminal information service), ASOS (automatic surface observation service), AWOS (automated weather observation system), HIWAS (hazardous inflight weather advisory service), or from ATC.
The wind is reported as the magnetic direction that the wind is blowing from, followed by the speed in knots (Nautical miles per hour) There is other important information obtained as well, but for this discussion, we will talk about the wind part only.
An ATIS broadcast for Hobby airport may sound like this:
“Hobby airport information sierra, two two five zero Zulu weather, wind one five zero at eight, visibility one zero, sky condition, few clouds at three thousand, temperature two eight, dew point two six, altimeter two niner niner eight.”
The reported wind is “one five zero at eight”, which means that the wind is coming out of the south, from a bearing of 150Â° degrees, at 8 knots The preferred landing runway should be oriented toward the south, as close to this bearing as possible If we look at the diagram for Hobby airport below, we see that there is one runway that is predominately to the south, and that is runway 17/35.
When landing on this runway, with a wind from 150°, the pilot would have a slight left headwind do deal with, but still aligned “into the wind”, more than any other runway, and this would be the best choice for landing in this situation.
If runway 17/35 were not available (due to closure or other traffic reasons), then the next best runway would be one of the 12 runways (12R or 12L), giving the pilot a right headwind.
Some airports have different criteria for landing and departing traffic, based on approach / departure requirements, ground handling, or other issues At KIAH airport, the 15/33 runways are almost always used for takeoffs, and the 26’s and 27 are almost always used for landing.
This works well due to the layout of the airport, since the terminal is in the middle, they land and taxi right up to the terminal, and when they depart, they taxi right out to 15L or 15R and depart without any extended taxi Even if the wind is somewhat out of the south, they will usually continue to operate this way.
The reasoning is this: the runway selection at a large airport based on wind is predicated by the planes taking off, not the planes that are landing the planes in the air are already airborne, and if a problem arises, they can go around However, a plane on the ground needs all the help it can get (by being as much “into the wind” as possible) to takeoff.
This usually works well at Bush airport, the larger jets can handle a pretty strong crosswind and not have too many problems landing on a runway that is not perfectly aligned with the wind Pilots flying into larger tower controlled airports will follow the instructions of ATC as to which runway to land on However, if a pilot is flying into an uncontrolled field, both takeoff and landing will be into the wind as much as possible.