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Falcons and Planes

  1. Sep 4, 2010 #1
    I recently heard from my friend that a flacon swoops down in a spiral (not spinning) motion to get a continuous view of its prey because it can see things clearly only in a 45-degree angle.(I don't know if this true, so please correct me if I am wrong.)

    I have even seen fighter jets doing the same thing (i.e. swooping down in spiral motion).
    Is there a reason why jets should move like that ?
    Is there a relation between movemont of a falcon and a jet ?
    and also What is a Vortex ?

    Please don't use heavy jargon, I'm just 15yrs old.
  2. jcsd
  3. Sep 4, 2010 #2


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    Welcome to PF, KauGan.
    Birds have extremely good vision, so I doubt the reason for a falcon's dive path that you mentioned. I refer you to the following for more proper information: http://jeb.biologists.org/cgi/reprint/201/3/403.pdf
    Once you have a handle on that, comparisons with aircraft can commence. :wink:

    Oh... and a vortex is simply a swirling motion is some medium. That could be a dust-devil or full-blown tornado, or a flushing toilet, or wake turbulence from the wings of an aeroplane...
  4. Sep 4, 2010 #3
    I would say that it is indeed for a better view. In an aircraft, the dashboard is a large blind spot, so by spiraling, the pilot would see all of it's target's surrounding symmetrically. (not that he actually needs to, because of cockpit instruments)

    By examining a falcon's face, it seems that it's own beak may also well be a blind spot. Spiraling would compensate for this.

    I have no reference, it's just an opinion.
  5. Sep 4, 2010 #4


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    I never considered the beak, Dr. At first read-through, it seemed like a silly idea. Upon trying out the concept, however, I realized that I do actually see my own nose as a "ghost image" (since it doesn't appear in the same visual field of each eye). My brain just automatically filters out the image unless I concentrate upon it. Since a bird's beak protrudes so much farther into the visual field, your idea makes a lot of sense.
  6. Sep 4, 2010 #5
    Just my opinion:
    Regarding a jet fighter purposely spinning on attack descent. I really do not think it has anything to do with enabling a wider field of view.
    After all, have you seen it through cockpit cameras? It's very disorienting and would seem, to me, to more confuse visual target ID.
    Moreover, on the vids I've seen, spiraling during attack is very rare, and often done as an avoidance maneuver against incoming fire.
    Also, the vids I have seen them doing this is because, well, they can. They are either practicing avoidance, getting more used to the feel of spinning, or just having fun.
  7. Sep 4, 2010 #6
    It's certainly not pratical for today's fighters, who do most real missions at night with nearly complete reliance on avionics.

    But birds are also known for doing some of their flying "for fun".
  8. Sep 4, 2010 #7
    Indeed, "nature" is not always survival/food/procreation specific.
    Some activities in nature are "just for fun"; whatever that means for a specific species.
  9. Sep 5, 2010 #8
    Thanks for all your answers.
    @Danger thanks for the PDF.:smile:

    I have another question.
    I heard that according to the laws of aerodynamics , the bumble bee shouldn't be flying but it flies due to the high frequency vibration of its wings which causes a vortex.

    How does the vortex help in the flight of the bee here ?:confused:
  10. Sep 5, 2010 #9


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    I'm afraid that your link doesn't work. Anyhow, my understanding of a bee's flight it that it isn't the frequency that matters; it's the fact that the wings twist in something like a whiplash movement on the downstroke. I'm not sure about that, though, so don't take my word for it.
    Last edited: Sep 5, 2010
  11. Sep 5, 2010 #10


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    Basically yes.

    The eyes of a falcon look sideways at about 40°. So to look directly forward (on the prey) in a straight dive, it would have to bend the head to the side. But that would mess up the aerodynamic shape of the body, causing more drag and turbulence. So it spirals with the head straight.

    A BBC documentary, where they attached a camera to a falcon, and filmed that dive.
    Last edited: Sep 5, 2010
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