The Forces That Keep Planes Aloft

by Max Moreno, age 13

To many, flight seems inexplicable as humans aren’t biologically built to defy gravity, yet inventors found a way to send thousands of tons of metal carrying hundreds of people soaring through the sky.

Despite flying on planes being a normal occurrence, many don’t know the science behind plane flight or the forces at play. Lift is what allows planes to fly. It is a force generated when air flows over and under their wings. As planes move through the air, the pressure above their wings becomes lower than the pressure below them, creating an upward force. However, lift isn’t only generated by the wings; every part of the plane contributes, thanks to its aerodynamic shape.

Planes experience other forces as they fly, such as drag, which is the wind and air resistance slowing the plane down as it moves. Another force is thrust, which pushes the plane forward with the help of its engines. The last force is gravity, which constantly tries to pull the plane down.

In simple terms, flight happens because engines generate thrust to push the plane forward, the wings and body shape create lift to push it upward, drag slows it down, and gravity pulls it down. When thrust and lift overcome drag and gravity, the plane stays in the air.

Race cars experience a version of lift, too, but in reverse. Drivers don’t want their cars to fly; they want them to hug the track. That’s why race cars are designed with “wings” at the back that create a downward force, helping the car grip the surface.

Birds, flying fish, bats, and insects all deal with lift, drag, thrust, and gravity thanks to their unique anatomies. Lift isn’t magic; it’s simply the result of pressure differences and motion that we see happening around us every day.

[Sources: NASA; Science News Explores]