Why do planes fly

The biggest reason for this altitude lies with fuel efficiency. The thin air creates less drag on the aircraft, which means the plane can use less fuel in order to maintain speed. Less wind resistance, more power, less effort, so to speak. Spending less on fuel is also great for airlines, for obvious reasons. So, flying too high can also cause problems. Plus, the higher a plane goes, the more fuel it has to burn in order to get there so there are some drawbacks with certain altitudes as well.

Flying higher means planes can avoid birds usually , drones, and light aircraft and helicopters, which fly at lower altitudes. Thrust is a force that moves an aircraft in the direction of the motion. It is created with a propeller, jet engine, or rocket.

Air is pulled in and then pushed out in an opposite direction. One example is a household fan. Drag is the force that acts opposite to the direction of motion. Drag is caused by friction and differences in air pressure. Gravity is a force that acts in a downward direction—toward the center of the Earth. There is an amazing video by MinutePhysics Youtube channel which explains how do airplanes fly. Check it out! This article was originally published with the title "The Enigma of Aerodynamic Lift" in Scientific American , 2, February How Do Wings Work?

Holger Babinsky in Physics Education , Vol. David Bloor. University of Chicago Press, Understanding Aerodynamics: Arguing from the Real Physics.

Doug McLean. Wiley, You Will Never Understand Lift. Peter Garrison in Flying ; June 4, Culick; July Already a subscriber? Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. In Brief On a strictly mathematical level, engineers know how to design planes that will stay aloft. But equations don't explain why aerodynamic lift occurs.

There are two competing theories that illuminate the forces and factors of lift. Both are incomplete explanations. Aerodynamicists have recently tried to close the gaps in understanding. Still, no consensus exists. Public Health. Climate Change. Support science journalism. Knowledge awaits. See Subscription Options Already a subscriber? Create Account See Subscription Options. Continue reading with a Scientific American subscription.

Flying higher means it would take a longer time to return to a safe altitude in case of an emergency, like rapid decompression, Beckman says. And the weight of the plane changes as the aircraft climbs higher into the sky.

This, combined with the thinner atmosphere at this height, creates less resistance. The direction of the wind is also an important factor. This also explains why you feel the plane slowing down during landing. In most cases, these planes use a piston-powered engine, which operates similarly to the engine in your car and with power that only allows for shorter flights, according to the National Business Aviation Association.

This type of engine prevents these smaller planes from reaching the same altitudes as commercial aircraft. Pilots also refrain from flying these types of planes at greater heights because of potential health risks like hypoxia, which is when tissues do not receive enough oxygen, according to the National Institutes of Health.