How Do Airplanes Fly?
Airplanes fly using four forces: lift (upward), weight (downward), thrust (forward), and drag (backward). Wings generate lift because air moves faster over the curved top surface than the flat bottom, creating lower pressure above the wing. When lift exceeds weight and thrust exceeds drag, the plane rises and moves forward.
Key Takeaways
- Lift is generated by the wing's shape (airfoil).
- Helicopters generate lift differently, using rotating blades that are essentially spinning wings.
- Planes can glide without engine power because lift still works - they trade altitude for forward motion.
Explanation
Lift is generated by the wing's shape (airfoil). The curved top and flatter bottom cause air to travel different distances. Air moving faster over the top creates lower pressure (Bernoulli's principle), while higher pressure below pushes the wing up. The angle of the wing relative to airflow (angle of attack) also contributes to lift.
Thrust comes from engines - either propellers spinning air backward or jet engines expelling hot gases. Newton's third law applies: pushing air backward propels the plane forward. Drag is air resistance that opposes motion. Airplane design minimizes drag through streamlined shapes.
For takeoff, engines create thrust to accelerate the plane. As speed increases, lift grows until it exceeds the plane's weight, and the plane becomes airborne. Pilots control the plane by adjusting engine power (thrust), wing flaps (lift), and control surfaces (direction). Landing reverses the process, reducing thrust and lift.
Things to Know
- Helicopters generate lift differently, using rotating blades that are essentially spinning wings.
- Planes can glide without engine power because lift still works - they trade altitude for forward motion.
- Supersonic flight involves additional physics as air behaves differently above the speed of sound.