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Commercial Airliners - Aerobatics?

Discussion in 'General Discussion' started by stuppy, 5 Jun 2006.

  1. stuppy

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    This is directed at the Aeroenthusiasts on here :)

    I myself enjoy looking at videos and pics of planes (flightlevel350.com and airliners.net being my 2 fave sites). One thing I have always wondered, What would happen if you were flying a 747-400 and you rolled onto its back in the air. Would it still fly? You can do it in Flight Sim ( :) ) but is it possible in the real world?

    LET THE GEEK AEROPLANE CHAT BEGIN!
     
  2. William

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    Wings would shear off/ stall or spin before you got it upside down.
     
  3. stuppy

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    Why though?
     
  4. FTM

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    I think you could barrel roll one..just very slowly.....it it can fly normally theres now reason why it wouldnt fly upside down surely?
     
  5. Rich_L

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  6. Visage

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    I would imagine the airframe isnt anywhere near strong enough to handle the loads. It would break up. Obviously a newer plane wouldnt even let you try.....
     
  7. Zip

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    You could do it very slowly.
    The problem would be the aerodynamics of it once upside down would force the place down towards the ground
     
  8. Visage

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    Except that lift would now be acting *with* gravity, rather than against it.....
     
  9. FTM

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  10. bam0

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    Why? Are you sure you know how wings work and lift is generated?
     
  11. tom_nieto

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    Last edited: 5 Jun 2006
  12. Zip

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    Isnt it to do with the curve in the wing?
    If the plane is upside down the curve is working to create down force
     
  13. Bes

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    ZIP is correct. Aircraft designed to fly upside down have specially designed wings. In a 747, the aircraft would effectively be undergoing 'negative lift' and plummet towards the ground.
     
  14. Vonhelmet

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    Exactly.

    See also: Formula 1 cars, spoilers.
     
  15. chrismox

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    Not strictly true. The elevator (stabiliser on some aircraft) is also a wing but with variable angle of attack. Aircraft with conventional wings can be flown upside-down using the deflection force of the 2 wings rather than the normal lift.

    Make any sense? No? :)

    I know that 737s have been barrel-rolled and, theroretically, a 747 could too. Whether it would be structurally sound afterwards is, I suppose, the key question.
     
    Last edited: 5 Jun 2006
  16. stuppy

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    Anyone wanna club together and get a few quid between us and buy a 747 and try it?
     
  17. VaderDSL

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    Crank up Flight Simulator 2004 someone and post a Fraps of it :p
     
  18. Scuzi

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    I've barrel rolled a BA 777-200 once and although we lost about 10,000ft in hte process, it still worked :p

    When I say BA 777-200, I mean the BA 777-200 full motion simulator btw ;)
     
  19. pieman109

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    Everyone here is forgetting one thing, "angle of attack". the p51 mustang built during ww2 had whats called symmetrical wings, ie: the aerofoil section was symmetrical (equal curve above and bleow the wing), also a B777 has a similar flow wing.
    As long as the aircarft has a postive angle of attack relative to the ground, the aircarft will stay in the air. A B747 already has a high wing angle of attack, so to fly inverted it'll need a lot of "nose down" relative to it's flight attitude to keep sufficient lift being generated to stay in the air, the engines would also have to be at a high power setting to maintain this.
    As far as the airframe breaking up goes, I doubt very much this would occur as the manouver would be carried out relatively slowly (you can't snap roll one of these 'frinstance, it's too big.) These airframes are built to withstand VERY heavy loads, if not, they wouldn't be allowed to fly with passengers.
     
  20. VaderDSL

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    I remember watching a program on Discovery a while back, probably on Discovery Wings, showing the testing they did on the wings, they strapped them up and used hydralics winches to pull the wings up to see how much load they could take.

    Damn, I think the bent the wings upwards so that the tips were nearly vertical before the wings snapped. :) Shows how tough the airframe is (well wings)