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Thread: OT - gravity always wins (unless your an eagle)

  1. #31
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    Quote Originally Posted by Evan
    I have designed model aircraft up to eight foot wingspan. They all fly very well. Your qualifications?

    One of my designs.



    They all follow the same rules when operating as a fixed wing aircraft as the eagle does most of the time. When flapping the situation changes for the worse in terms of load capacity. Descending flight doesn't increase the load capacity of the wing spars or the flight feathers and it doesn't change the weight of the object being carried. For it to change the apparent weight of the object it would have to be in constant downward acceleration.

    Evan -- iv got little planes that fly very well also,,,, like I stated - get off the constant power propeller kick, Birds don't fly level flight or make gains that way, their propulsion system is intermittent be it an owl or eagle - one may use speed and have to propel force backwards to maintain the speed and the other may use a more direct lift approach --- either way -- the fiddler not only has to be paid -
    Due to the intermittent propulsion system it means that WAY more force is intermittently being applied to the birds airframe and wing structure to keep its weight aloft, In fact its about double...
    Not so if the bird gets to glide down at a radical angle, ZERO intermittent and 100% controlled drag,
    So take the maximum of the intermittent force that the birds capable of applying and now instead of it only happening half the time it can be concentrated 100% and controlled even better without the consideration of propulsion losses... There fully capable of not only glide coasting their own weight but the weight of another eagle that's totally tucked with minimal drag --- as can be seen in mating rituals or even fighting, its by far not even close to their limitations as this can be exceeded drastically.


    as I previously mentioned --- (up to a certain point) all that has to be adjusted is the air speed and angle of descent.

    That's my qualifications...

  2. #32
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    I have watched the video several times and I believe it is real. The eagle, while not actually riding the pray, is not letting go of it and is more gliding it down to the ground. It is big enough to do that.

    Looks like they try to take off with it, but I bet more often than not, the sheep just gets dragged off the cliff. No problem, it either dies or ends of crippled in a place where the eagle can feed at will.
    Gene

  3. #33
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    Quote Originally Posted by Evan
    He is supporting the full weight of whatever he is carrying regardless of the gain or loss in altitude, the same as any aircraft.
    Even in an accelerating descent? If I hang on to you while we're both falling, who is supporting who? If I have more wind resistance than you do (because of my larger surface area ), I will only support the differential in drag forces - no? I fail to see how the eagle/prey thing is significantly different.

  4. #34
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    Quote Originally Posted by Evan
    There is no such thing as "riding the kill down". He is supporting the full weight of whatever he is carrying regardless of the gain or loss in altitude,


    Wrong - the drag vector changes and much of the air drag is changed from horizontal to vertical --- the bigger the increase in drop rate the more that is converted in keeping the load lighter --- it all ties in with terminal velocity of the item being carried and the angle at which its vectoring down...

  5. #35
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    I have watched the video several times and I believe it is real. The eagle, while not actually riding the pray, is not letting go of it and is more gliding it down to the ground. It is big enough to do that.
    Even in an accelerating descent?
    It isn't an accelerating descent. If you watch the video the eagle actually pulls up from the descent making it less steep. To make it possible to carry the load as shown the acceleration would have to be around 2/3rds or more of free fall. Impossible.

    Gliding the prey to the ground is no different than level flight as far as the load is concerned. It's basic aerodynamics and physics. The effective weight of the aircraft and the payload do not change while it gains or loses altitude. That only happens when it accelerates in any direction.

    Boomer, I'm not going to reply to your comments as you just don't know what you are talking about when it comes to aerodynamics.
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  6. #36
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    Quote Originally Posted by Evan

    Boomer, I'm not going to reply to your comments as you just don't know what you are talking about when it comes to aerodynamics.
    I am calling 'pot, kettle' on this one.

  7. #37
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    Unless you can substantiate your comment it serves no purpose except for stirring the pot. Is that your intent?
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  8. #38
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    Quote Originally Posted by Evan

    Boomer, I'm not going to reply to your comments as you just don't know what you are talking about when it comes to aerodynamics.

    I was trying to be nice
    Now that youv made that statement and put your foot in your mouth --------

    I spank you every single time with this subject and you know it -- your not going to reply because You don't know how the world of flight works, and your not going to reply due to you being incapable of doing so,

    Your wrong ------------- The load gets lighter as the angle increases stymie,,, deal with it...

    This isn't some "shielded payload" that's in the belly of a freakin aircraft pilgrim... ;>}
    Last edited by A.K. Boomer; 01-26-2010 at 04:05 PM.

  9. #39
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    Evan, it would be more pertinent if you could substantiate the claim you made against Mr Boomer.

  10. #40
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    It's based on past history over the years in a number of posts that you can look up if you wish. They are all to do with how aircraft fly and clearly illustrate that Boomer is using his intuition rather than knowlege of the subject. Intuition is a very poor guide to how aerodynamics works.
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