How Do Airplanes Fly?

What You'll Learn

• Airplanes need four forces to fly: lift, weight, thrust, and drag
• Wings are shaped so air moves faster over the top than under the bottom
• Faster air on top creates lower pressure, which pulls the wing upward — that's LIFT
• Engines give THRUST to push the plane forward
• DRAG is the air pushing back on the plane
• WEIGHT is gravity pulling the plane down

Words to Know

Lift

The upward force that keeps a plane in the air

"The wing created lift."

Thrust

The forward push from an engine

"The jet engines gave thrust."

Drag

Air pushing back on a moving plane

"Drag slows the plane down."

Wings

The big flat parts that help a plane fly

"The wings curved to make lift."

Check What You Learned

Fun Facts

• Flight depends on four forces: lift, weight (gravity), thrust, and drag

  Source: NASA Glenn Research Center

• An airfoil wing shape causes air to move faster over the curved top surface than the flatter bottom

  Source: NASA

• Faster airflow over the wing creates lower pressure above the wing (Bernoulli's principle)

  Source: NASA

• Higher pressure below the wing pushes upward, generating lift

  Source: Britannica

• Engines provide thrust to overcome drag and move the aircraft forward

  Source: Federal Aviation Administration

• When lift exceeds weight, the aircraft climbs; when thrust exceeds drag, it accelerates

  Source: NASA