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Angle of entry

  1. Aug 6, 2014 #1
    Hi guys, firstly, I am NOT a physicist and I apologize for invading your forum, but I am curious about something:

    Is it theoretically possible for a Boeing 777 to hit the ocean at the perfect angle and speed so that it dives right through the water, like a diving sea bird, without breaking apart? I realize that birds tuck their wings when they dive and the wings separating are the sticking point for me right now.

    Hopefully there are some Hyper Physicists or Aviation Engineers hanging around.

    Thanks so much for your time.

    p.s. I'm assuming a perfectly calm sea
     
  2. jcsd
  3. Aug 6, 2014 #2

    phinds

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    Doesn't really take much of an engineer to tell you that the answer to that is a definite no. Hitting water at even the stall speed of a 777 wouldn't be a lot less gentle than hitting the ground and even if the front went in, the wings would rip off
     
  4. Aug 6, 2014 #3

    lisab

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    I'm not an aerospace engineer, but I think phinds is right.

    There have been instances of large planes making water landings "successfully", though:

    plane_crash_redux_01.jpg

    http://en.wikipedia.org/wiki/US_Airways_Flight_1549

    This might suggest the "perfect angle" is close to zero.
     
  5. Aug 6, 2014 #4

    russ_watters

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    Agree with both.

    [edit: why does my post have a title?]
     
  6. Aug 6, 2014 #5

    phinds

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    Yes, and I think you realize it fully, but just want to be clear that that does NOT define a "perfect angle" in response to his question, which has the plane becoming a submarine, but rather answers the question "what's the best angle to hit the water and FLOAT and not break up?".

    The answer to his question as asked is, there is no such angle.
     
  7. Aug 7, 2014 #6
    Thanks a lot guys. I figured that may be the case, but wanted educated opinions.
     
  8. Aug 7, 2014 #7

    collinsmark

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    That's because you're lucky, post #4. :biggrin:
     
  9. Aug 7, 2014 #8

    Evo

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    And why, you might ask, does post #4 have a title? Because Evo couldn't always remember the thread title when she was halfway down the thread, so Greg agreed to add the title back to the 4th post so I wouldn't have to scroll all the way back to the top to find it.
     
  10. Aug 7, 2014 #9

    russ_watters

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    Wait, really?
     
  11. Aug 7, 2014 #10

    Evo

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    Yes. Ask and ye shall receive. When I'm moderating a thread in GD, often by the time I get to the thread bottom I'm wondering What the Heck was this thread supposed to be about? Often you can't tell from the posts, and we didn't have the wormhole.
     
  12. Aug 7, 2014 #11
    Actually that helps me too. At my age I do occasionally forget the title of a thread.:redface: It is usually a bit further down than post four.:devil:

    I was just thinking that this might discourage people who are about to go off topic. Oops that was off topic.
     
  13. Aug 7, 2014 #12

    RonL

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    Can't resist this one,
    As others have said NO!
    The perfect angle for the fuselage is 90 degrees to the water surface, (it might be OK) but the wings now produce lift in a hydraulic (non compressible) environment which would rip them from the body (instantly).
     
  14. Aug 7, 2014 #13

    jim hardy

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    Ever watch pelicans dive for fish?

    They fold their wings in and way back from flying position, and their long long beak breaks the water.

    (photo courtesy of http://jerryjourdan.blogspot.com/2009/11/sanibel-island-fl-21-nov-2009.html)

    BrownPelican8597b.jpg

    and a pelican's stall speed is maybe a tenth of a jetliner's .
     
  15. Aug 7, 2014 #14

    RonL

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    Yes, with a very short history of Gulf shrimping that is a very common sight, also I have watched a hawk take the same path from about 500' into a field of grass and weeds, then fly out with a snake in his claws. I would love to see how he checked his descent at those last few feet ??

    What are you indicating in relation to the jet plane ?
     
  16. Aug 7, 2014 #15

    jim hardy

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    Same things you said in #12:

    Pelican enters with his fuselage perpendicular

    but is able to streamline his wings so they aren't snapped off.
     
  17. Aug 7, 2014 #16

    RonL

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    Thanks Jim,
    Just wanted to make sure I didn't miss the intended point, :smile:
     
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