Can anybody tell me how aircraft fly up side down? I'm an under grad aero student and cant see how aircraft do. Can any aircraft theoretically fly up side down?
No, you've fallen prey to the most pervasive fallacy in aerodynamics - the Equal Transit Time fairy tale. Google that phrase, and you'll find many places that show how it's wrong.paddy-boy66 said:but doesn't the resultant lift always act in one direction relative to the "upper" surface so if its upside down wont the "lift" be downwards? Am i being stupid in saying this?
Well considering that some aircraft fly upside down, it is actual rather than theoretical. Practially, it is limited to small aircaft, acrobatic and jet fighters, and the like.paddy-boy66 said:Can any aircraft theoretically fly up side down?
Do you also have a crash-team sim?Averagesupernova said:Hmmmmmmmmm. I'll have to try that with a 747 on my flight sim.
I think, perhaps, by "any", he meant every. Though pretty much any *airfoil* is capable of producing negative lift (or positive lift while inverted), many *planes* cannot fly inverted for various other reasons (structural, fuel flow, lift/drag ratio, etc).Astronuc said:Well considering that some aircraft fly upside down, it is actual rather than theoretical.
It's called a knife edge.paddy-boy66 said:so then how do aircraft fly perpendicular to the ground, or is there a component of the thrust equal to g?
I don't want to get too much into semantecs, but since it was a 1g, transient maneuver, I don't know that I'd call that "flying upside-down".cyrusabdollahi said:You want to fly an airliner upside down, sure here it is:
If done properly, the forces are not a problem, nothing would be ripped off.
It's called a chandelle and it's a 1g manuver. If your airplane is going to fall appart at 1g, you have bigger problems.
One thing is inverted, positive-g flight, like a barrel roll. Yes, almost any airplane can do that, as Tex Johnston demonstrated on the Dash 80. The aerodynamics are the same as regular flight.I don't want to get too much into semantecs, but since it was a 1g, transient maneuver, I don't know that I'd call that "flying upside-down".