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Four Forces Act on an Airplane

And airplane flying with arrows showing how the four forces of flight are interacting with the plane.
Credit: National Air and Space Museum, Smithsonian Institution

When an airplane is flying straight and level at a constant speed, the lift it produces balances its weight, and the thrust it produces balances its drag. However, this balance of forces changes as the airplane rises and descends, as it speeds up and slows down, and as it turns. 

Categories: Forces of Flight, Lift, Drag, Thrust, Weight
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