Wind

Wind Wind is a motion of air due to difference in air pressure between two areas. A device that measures wind speed is called the anemometer. The mechanical anemometer (with paddles) is most often used, but there are ultrasonic, laser-Doppler, hot wire anemometer and Pitot tube anemometer. Wind direction is determined by the wind vane and its arrow indicates the direction from which the wind is blowing.

At the airports, wind is measured at a height of 10 m above the ground on both thresholds of the runway. At the smaller airports, the anemometer is located at only one end of the runway. Wind is a very important meteorological element in aviation because it can increase or decrease the relative speed of the aircraft and thus lengthen or shorten the required distance for take-off or landing. Therefore, the heading of the runway is determined by the direction of the wind.
 
It should be noted that during landing or take off of the aircraft crosswind is especially dangerous. Therefore, the runways are generally built in the direction of prevailing winds, when possible due to terrain.