why doesn't gravity pull airplanes to the ground.?

Answer 1

Flight is based upon four factors; gravity, lift, drag and thrust. As long as lift is grater that gravity the plane stays in the air. As long as thrust is grater than drag the aircraft moves forward.

Answer 2

Gravity always exerts a downward force on aircraft and everything else. Aircraft overcome the force of gravity by lift, one of the principles that makes aircraft fly. Thrust overcomes drag pulling the plane forward against the air. As the airfoils of the wing are pulled forward, they generate lift which overcomes weight (or the downward pull of gravity). As the amount of lift overcomes the weight, the plane becomes airborne.
Aircraft don't defy gravity, they only overcome it for short periods of time. As long as they have sufficient fuel for thrust and/or sufficient lift generated (as in the case of a glider riding thermals), and all the control systems are operational, aircraft will remain airborne.

Answer 3

flying an airplane or helicopter is the manipulation of the forces of thrust, drag, lift and gravity.Gravity is overcome buy the lift generated by the wing's shape and it's movement through the air. Most of the lift is generated by the shape of the wing being curved slightly, thus the air speeds up faster than the bottom part of the wing, thus creating a low pressure, that sucks the wing up and provides most of the lift of the wing.

Answer 4

Gravity does pull aircraft to the ground. It is the lift generated by the lifting surfaces which keeps aircraft airborne. The moment the lift component exceeds the weight of the aircraft, it gets airborne and vice versa comes down when reduced. Lift is created by differential pressure generated by the wings in fixed wing aircraft once it starts to move, and by the rotors in helicopters when they start to rotate.

Answer 5

The reasons that it doesn't go crashing to the ground are two things: the wings and the jet engines.

The wings are not actually flat. They are slightly curved on the top and flat on the bottom so that air flows slower over the top of the wing than the bottom of the wing, which means since there's more air going faster at the bottom, it pushes the wing up, and the airplane. Wings are also sometimes tilted up so that the air takes even slower to go over the top of the wing, making the plane even lift higher and quicker. Here's a picture so you can understand it (don't pay any attention to the blinking arrows or the numbers and letters. Look at the lines above and below the wing) http://www.allstar.fiu.edu/aero/images/lift-v.gif


The jet engine is what propells the airplane, or in other words, makes the airplane move forward. They are those round things under the wing http://a.abcnews.com/images/Technology/nasa_google_070913_ms.jpg http://www.aviatorservices.com/images/Boeing%20Business%20Jet.jpg and sometimes on the tail of the plane http://www.silentthundermodels.com/images/desktop/commercial/boeing_727-200_continental_G6810P3R.jpg

This is how they work: They suck in air at the front, the air gets compressed (gets very presurrized) inside the engine, gets jet uel sprayed in it which ignites the pressurized air, and is blown out the back of the engine, therefore creating the plane to move forward at 600 mpg.

Fighter jets like these http://www.defenseindustrydaily.com/images/AIR_F-22_10-Oc_Over_Mountains_lg.jpg http://www.sci.fi/~fta/f4_31l.jpg http://www.atpm.com/12.05/eea-airventure/images/F-16%20Fighting%20Falcon.jpg have way more powerful engines than the big jets and can fly over 1,300 mph! Their engines are in different places than where a normal jet's engines would be. They are also shaped differently than a normal jet's engines, and are not pod shaped like a normal jet. The first photo has its engines right beside the body of the aircraft, and under its wings (the engines look like square openings). The second photo's engines are right beside the aircraft's body too, but are not under the wings (they are also the rectangle openings, and are more visible to see). The third photo's engine is at the bottom of the aircraft's body, and is not attached to the wings. It is more of a smiley face shape tha the others

Answer 6

Gravity DOES pull down on aircraft...
That's why they call it heavier than air,
but the virtue of an airplane or helicopter
is to develop lift stronger than the weight of gravity

Answer 7

In a nut shell, the airplane's wings are designed to create a force that overcomes gravity and pulls the aircraft upwards.....Bernoulli's principal
http://www.mste.uiuc.edu/davea/aviation/bernoulliPrinciple.html

Answer 8

it does. but the gravity is ballanced by the lift produced on wings. As soon as the lift dissapaers, the gravity wins and takes its share :)
on some occasions the lift is substitued by the engines thrust ,like in Sukhoi 27 flanker's Cobra and related maneuvers or the aerobatics specials, where the engine power itself is greater than the weight of the aircraft

Answer 9

Ever stick your hand out of a car window and turn the front of your hand up and feel the wind lift your hand? Wings air foils act in much the same way. Air moving slower under the wing longer path and faster over the top of the wing makes lift. Air planes are held aloft with air.

Answer 10

I am not a specialist in aeronautics but from what I know, as the plane is moving forwards (thanks to its reactors or its helix) there is an air stream around the wings and, due to their shape, it causes the pressure to be higher under the wings than on them, so the pressure pushes the plane up from under the wings, and this force balances the gravity.