How can aeroplanes fly upside down?

Question

If the wings give lift then when upside down the plane should go down and not be able to stay aloft.

Answer 1

Ok - for this example assume we have a small plane, like a bi plane - it's the same theory for all planes, but with different ratios and stuff!

In order for the plane to keep a constant height the wing needs to be at about a 4% angle to the on-coming wind (at normal speed) so the wing is normally fixed at this angle - this means when the plane is flat in the air the wing is at 4% at the altitude will stay the same. So when the plane is upside down the pilot aims the nose up by 8% - 4% to counteract the original 4, and another 4% so the wing is now at a 4% angle to the on-coming wind again.

I hope I explained that clearly enough!

Answer 2

A flying aircraft is all about a balance of 4 forces: thrust, lift, drag, and weight. Lift and weight have constant directions, lift acting upwards and weight acting downwards. The other two, thrust and drag depend on the orientation of the aircraft--thrust usually taken to be forward out the nose of the plane and drag rearward out the tail. An aircraft that has its nose pointed at an incline to the horizontal can generate additional upward force from the thrust of its engines. The steeper the angle, the more the engines act to lift the plane.

In addition, the effects of the wings are also highly dependent on the angle. When wings are upright and level with the horizontal, they produce lift and drag. When they are inclined to the direction of airflow, both the amount of lift and drag can increase significantly. Thus a plane flying upside down could still gain enough lift from the wings if they are angled appropriately. The additional drag from angling the wings means that an upside-down plane needs lots of thrust to keep from decelerating. This is why you see mainly high-performance military or stunt aircraft flying upside down for extendend periods of time.

Answer 3

It's all in the dynamics of the air over the wing. Science teachers and books in most schools are totally wrong. It has very little to do with the Bernoulli effect (air going faster over the top surface creates low pressure). If that were the case, it could never fly upside down.

In reality there is some lift gained by the angle of attack where the bottom surface of the wing pushes air down and is lifted up. The second part happens when the air over the wing is forced downward because of fluid mechanics. By Newtons laws, with air pushed down, the wing gets pushed up. It doesn't matter if you're right side up or upside down. Read about it here.

http://www.livescience.com/technology/060828_how_planes_fly.html

Answer 4

I think most planes can fly upside down if the fuel systems let them. The lift is given by the angle of attack of the wings. It will be less efficient than cruising the right way up because the angle of the wings to the body will not be perfect.

Answer 5

its to do with the aero dynamics of the aircraft all fixed wing aircraft can go upside down av seen a beoing 747 do a barrel roll lmao but erm the wing is designed so that the fast air moving over the top of the wing produces lift and this can be reversed when upside down with falps and airlerons etc but some helicopter can do loops and stuff its all do to with the way they pass through the air and what the criticle angel is of the wing produces lift when upside down....

Answer 6

It is due to the aerodynamics of the aircraft, if enough lift can be generated then it is possible to maintain flight upside down. in theory a Boeing 747 is so aerodynamic it can fly upside down. but put to the test the plane would break apart in the process as it does not have enough strength.

Answer 7

The angle of the wing has to be kept slightly up to give lift.

Answer 8

Jet powered aircraft can fly upside-down as there is enough forward momentum to keep it going straight. Civilian aircraft would struggle.

Answer 9

The whole aerodynamics thing is a lie put about by the CIA to hide the fact that it's actually fairy dust that keeps planes in the air. You've spotted the flaw in their conspiracy!

Answer 10

They change the angle of the control surfaces.