How do some planes manage to fly upsidedown? (According to the aerofoil principle the lift would be downwards)

Answer 1

Aerobatic aircraft typically have very little lift from the camber of the wing, they use the angle of attack to provide lift. When inverted they simply pitch the nose up and still have lift.

Answer 2

Oh boy, here we go again.............



You’ve probably been told that an airfoil produces lift because it is curved on top and flat on the bottom. But you shouldn’t believe it, not even for an instant.

Presumably you are aware that airshow pilots routinely fly for extended periods of time upside down. Doesn’t that make you suspicious that there might be something wrong with the story about curved on top and flat on the bottom?

Here is a list of things you need in an airplane intended for upside-down flight:

* You need super-duper seatbelts to keep the pilot from flopping around.
* You need to make sure the airframe is strong enough to withstand extra stress, including stress in new directions.
* You need to make sure that the fuel, engine oil, and battery acid stay where they are supposed to be.

You will notice that changing the cross-sectional shape of the wing is not on this list. Any ordinary wing flies just fine inverted. Even a wing that is flat on one side and curved on the other flies just fine inverted, . It may look a bit peculiar, but it works.

The misconception that wings must be curved on top and flat on the bottom is commonly associated with the previously-discussed misconception that the air is required to pass above and below the wing in equal amounts of time. In fact, an upside-down wing produces lift by exactly the same principle as a rightside-up wing.
airfoil-terms

To help us discuss airfoil shapes,

The chord line is the straight line drawn from the leading edge to the trailing edge.
The term camber in general means “bend”. If you want to quantify the amount of camber, draw a curved line from the leading edge to the trailing edge, staying always halfway between the upper surface and the lower surface; this is called the mean camber line. The maximum difference between this and the chord line is the amount of camber. It can be expressed as a distance or (more commonly) as a percentage of the chord length.

A symmetric airfoil, where the top surface is a mirror image of the bottom surface, has zero camber.

Rudders are airfoils, too, and work by the same principles.

At small angles of attack, a symmetric airfoil works better than a highly cambered airfoil. Conversely, at high angles of attack, a cambered airfoil works better than the corresponding symmetric airfoil. otherwise the two are pretty much the same.
At any normal angle of attack (up to about 12 degrees), the two airfoils produce virtually identical amounts of lift. Beyond that point the cambered airfoil has a big advantage because it does not stall until a much higher relative angle of attack. As a consequence, its maximum coefficient of lift is much greater.


At high angles of attack, the leading edge of a cambered wing will slice into the wind at less of an angle compared to the corresponding symmetric wing. This doesn’t prove anything, but it provides an intuitive feeling for why the cambered wing has more resistance to stalling.

On some airplanes, the airfoils have no camber at all, and on most of the rest the camber is barely perceptible (maybe 1 or 2 percent). One reason wings are not more cambered is that any increase would require the bottom surface to be concave — which would be a pain to manufacture. A more profound reason is that large camber is only really beneficial near the stall, and it suffices to create lots of camber by extending the flaps when needed, i.e. for takeoff and landing.

Reverse camber is clearly a bad idea (since it causes earlier stall) so aircraft that are expected to perform well upside down (e.g. Pitts or Decathlon) have symmetric (zero-camber) airfoils.

We have seen that under ordinary conditions, the amount of lift produced by a wing depends on the angle of attack, but hardly depends at all on the amount of camber. This makes sense. In fact, the airplane would be unflyable if the coefficient of lift were determined solely by the shape of the wing. Since the amount of camber doesn’t often change in flight, there would be no way to change the coefficient of lift. The airplane could only support its weight at one special airspeed, and would be unstable and uncontrollable. In reality, the pilot (and the trim system) continually regulate the amount of lift by regulating the all-important angle of attack

Answer 3

Angle of attack. The camber (curvature profile/cross-section) of the wing is one thing; the angle it is flown relative to the airflow is another. The other answer said "pitch the nose up" That terminology can be a little confusing when inverted. It would be forward stick when inverted to increase angle of attack--the opposite of normal, un-inverted flight. You fly the airfoil at a positive angle of attack, using forward stick when inverted as necessary to accomplish the required AOA, which contributes to the production of lift. Lift (vertical lift component) is still acting "up", relative to the sky and the ground, but the control movements are reversed.

Answer 4

You may have noticed that the rear edges of the wing are equipped with movable surfaces. These movable surface planes are called ailerons. Although the lift of an upside-down airplane would be compromised if the wings were solid, the pilot can maneuver the ailerons upward to regain a lift foil edge.

Answer 5

Just to confuse the issue even more, try this question. How does an airplane fly on knife edge? Hint. The shape of the wings doesn't matter.

Answer 6

Might have something 2 do with forward motion ! IF U were upsidebackards & not moving {in the sky } --- where wood U B ? Duh ! (note spelling)

Answer 7

angle of attack

Answer 8

its magic... cows are cool