Here's a page for you to explore the relative velocity between an aircraft in flight, the ground, and the air through which the airplane moves. In this animation, the white clouds move relative to the ground at the wind speed, the airplane moves relative to the ground at the ground speed, and the airplane moves relative to the air at the airspeed. Airspeed is the important velocity for the generation of lift and drag. Notice that both aircraft have the same ground speed (200 mph). The top aircraft flies with the 40 mph wind, so its airspeed is 160 mph. (Airpseed = Ground Speed - Wind Speed; 160 = 200 - 40 ). The lower aircraft flies into the 40 mph wind, so its airspeed is 240 mph. (240 = 200 - (-40) ). More information about these velocities is given on the Relative Velocity Slide.
Last Updated Thu, Jun 12 04:47:01 PM EDT 2014
by Tom Benson