How can planes fly upside down?

Question

I understand how a plane flies due to the shape of their wings and Bernoulli's principle and all that jazz.

How can they fly upside down though?

Surely if you fly upside down the lift from the wings will push the plane towards the Earth which will add to the force from the weight of the plane and there will be no upward force at all?

Answer 1

Planes designed for aerobatics (which are the ones you mostly see upside down) often have symmetrical aerofoils with the wings set at zero incidence on the fuselage. Normal aeroplanes have assymetrical aerofoils on wings set at around 14 degrees to the horizontal. They will for this reason often fly slightly nose up when flying the normal way. They also need modified fuel and oil systems for the engines, especially piston engined planes like the Pitts Special, so they can utilise fuel and oil even when inverted.

They will also often have short wings to increase the roll rate - a Pitts for example can rotate completely in around 2 seconds. If you flick it (make one wing stall) you can rotate completely in around 1 second.

Answer 2

This is due to the making of the airfoil the aircraft.. old air crafts used to have their airfoils kind of straight which makes it harder to go up and down.. nowadays with their airfoils bent downwards so that the the difference between the air going above the the wing and the below the wing make the change in heights.. so normally when the plane is not banked and moving straight it would automatically go upwards so to make it go straight the pilot has to make the nose a bit heading down.. when upside down the opposite happens and the pilot has to push the other side.. with military planes , jet planes, have it very easy since they have a big power supply that can make it feel the same even if the plane was flipped upside down.. this is a nice good question

Answer 3

Àlso see resolved questions.
Simply put, the wing can generate lift in the up direction even when it is flying upside down. This is done by angle of attack. That's the angle of the wing relative to the airflow. The wing is cambered to produce lift more efficiently in the normal straight and level flight but it can still produce lift upside down.

Answer 4

The natural tendency for an upside down plane flying at normal speed will be to head downwards. You gain upward force by adjusting the flaps (and asking all the passengers to kindly crawl from the ceiling back to their seats).

Answer 5

Bernoulli's principle still applies due to the camber of the wing is somewhat symetrical. But a regular plane can not withstand flying inverted due to the fuel tanks are gravity fed. meaning gravity pulls fuel into its necessary locations.. however .. how does it stay flying inverted... well drive a car fast enough.. without governers and a car will fly.. not effeciently but will fly..

Answer 6

It's the elevator on the tail that controls the airplane from going up or down. As long as the engine is providing enough thrust, the wings will do their job of holding the plane aloft.

Answer 7

The ailerons dear boy. They can change the lift coefficient of the wings so that a plane may fly up side down.

Answer 8

usually the only planes that fly upside down for extended periods of time are jet propelled military-grade fighter planes and as far as i can tell the jets push the planes so hard that lift is not as much of a factor as it normally would be within conventional aircraft...but to be honest i don't really know...

Answer 9

Sure planes can fly upside down- all those fancy fighter planes can do loads of tricks like that!!

Answer 10

You are correct in assuming that you will have negative lift.
This loss of lift must be compensated for by extra engine power.
Even with the extra power, though, the duration of inverted flight is quite limited.
(Not recommended after a liquid meal.)