special sock with red and white stripes for measuring wind strength and direction is installed on airfields and runways

special sock red white stripes measuring wind strength direction installed airfields runways speed flag air sign measurement weather indicator storm airfield instrument airport meteorology cone aviation forecast striped force anemometer windsock blowing breeze safety danger airplane aircraft parachute paragliding warning hurricane runway conditions flight sail flying downwind transportation takeoff aerodrome safe copyspace helicopter course aeroplane intensity shear mountains detection