|MLA Citation:||Bloomfield, Louis A. "Question 646"|
How Everything Works 20 Apr 2018. 20 Apr 2018 <http://howeverythingworks.org/print1.php?QNum=646>.
A helicopter spins its wings around in a circle so that they move through the air even when the helicopter itself is stationary. Normally, these rotating wings are called blades. Again, the air flows faster over each blade than beneath it and there is a net upward pressure force on each blade. These upward forces support the helicopter and they also allow it to tilt itself—by adjusting the angle of each blade as the blades turn, the helicopter can obtain twists from the air so that it tilts one way or the other. Once the helicopter has tilted, it can use some of the lift force from its blades to push it horizontally so that it accelerates forward, backward, or toward the side.