Re: lift vrs speed on a wing

Hi Jack,

It is true that lift is a function of how fast the wing is moving through the air.  And the faster you 
go, the more lift you get.  So, how do they deal with this in an airplane?  Well, the next time you 
look at an airplane wing, notice that there are panels on the trailing (back) edge of the wing.  
There are usually several of them - the ones nearest the body of the airplane are called flaps.  
The pilot can extend and contract these panes, which changes the shape of the wing.  By 
changing the shape of the wing, it changes the "coefficient of lift" which can be thought of as 
measure of how much lift produced with velocity.  

The way most airplanes are designed, the wings are shaped so that when the plane is flying at 
cruising speed, they are producing the right amount of lift to equal the weight of the airplane.  
When the plane is flying slower, that is when the pilot uses the flaps to control the amount of lift 
the wing produces.  You'll notice when flying on a commercial airliner that the flaps are extended 
while taxiing out to the runway and then retracted shortly after takeoff.  likewise when the plane 
is slowing down for landing, the flaps are extended again.

For an excellent discussion, please visit:
 http://travel.howstuffworks.com/airplane.htm

-Steve