Lifting body + prone position ?

Discussion in 'Hangar Flying' started by Retroflyer_S, Sep 27, 2015.

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  1. Sep 28, 2015 #21

    Retroflyer_S

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    Yes definitely....pure lifting body without wings is pretty much obsolete in homebuilding for sure.
     
  2. Sep 28, 2015 #22

    henryk

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  3. Sep 28, 2015 #23

    Retroflyer_S

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    Last edited: Sep 28, 2015
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  4. Sep 28, 2015 #24
    Maximum rate of climb < 0.
    images.duckduckgo.com.jpeg
     
  5. Sep 28, 2015 #25

    Retroflyer_S

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    That is a re-entry vehicle it is not allowed to lift.
     
  6. Sep 28, 2015 #26

    Doggzilla

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    Its got lift, at least more than a reentry capsule. I think the joke was that it was unpowered.
     
  7. Sep 28, 2015 #27

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  8. Sep 28, 2015 #28

    BJC

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    The Shuttle flies final at a glide ratio of anout 4.5 : 1, just slightly steeper than a Pitts.


    BJC
     
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  9. Sep 28, 2015 #29

    DangerZone

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    Interesting testing methods... :)

    The guy really made an effort, but it would also help to see some old prone position testing information to skip trying to reinvent the wheel.
    This is a pic from the 1940s when the Americans made some good research on the subject:
    airforce.jpg

    The wingsuits and wingbodies are an excellent way of flying, visibility is excellent. However, there might be some who will object about the head eing 'too exposed' or god knows what.

    yves-rossy-flight.jpg

    Then there was a Homo Avis some half a century or so ago...
    Homo_Avis.jpg

    But eventually not many went that way because flying in prone position takes some time to get used to and many ergonomic solutions to ease longer flying hours.

    One thing that is sometimes problematic is pulling/pitching up suddenly because it does blurr the vision and can lead to a sudden redout. Not a good thing if you are rocketing through some trees/canyons at speeds over 200kts.
     
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  10. Sep 28, 2015 #30

    bmcj

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    So, does that make the Pitts a good reentry vehicle?
     
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  11. Sep 28, 2015 #31

    bmcj

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    This is not aimed at you DZ... I'm just using your post as a 'jumping off' point.

    Ouch... talk about torturing a lab rat!

    I think the only reason he gets decent forward visibility is because he flies at such a high angle of attack; if he flew flat, he would really have to bend his neck upward drastically. Just for fun, put on a motorcycle helmet, lay face down on your bed with your head and shoulders hanging over the edge, and hold you head up or level for as long as you comfortably can. I don't think it will be very long.

    I mentioned this one before... the "Switchblade" Phasst Glider.

    bondphasst1.jpg

    PHASSTex.jpg

    PHASSTcr.jpg
     
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  12. Sep 28, 2015 #32

    BJC

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    Climate control could be a problem.


    BJC
     
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  13. Sep 28, 2015 #33

    danmoser

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    The prone position does solve some visibility issues, but this is not a profound new discovery.
    .. Wright Brothers, DaVinci, Icarus, etc..
    In fact, isn't EVERY flying creature found in nature a face first flier? :ponder: :gig: :ban:
     
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  14. Sep 28, 2015 #34

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    If you push your elbows out like wings you get 20 cm ( 8 inches ) slimmer space to be at.

    I recall the Luftwaffe did similar experimenting as well. Some test planes too.
     
  15. Sep 28, 2015 #35

    DangerZone

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    I have the old model of the Z1 helmet which does allow pretty good visibility skydiving at +300km/h speeds even when looking up slightly. Sure, it does require some effort and strong head/neck muscles but how long do you want to stare up into the blue sky? If longer than a (split) second, I can always fly upside down and do some backflying for a while. The motorcycle helmet is not good for testing at higher speeds, it is bulky, has a high drag and pretty circular form which is good only for hiding behind a tiny motorcycle wingshield. Enough to say that the speed with a motorcycle helmet can be below 300km/h and with the Z1 above this speed on the same R motorcycle.
    z1-hp.jpg

    Even when trekking without the wingsuit my body is slightly head down and still I can see other skydivers who are above my horizontal flying level. The design and aerodynamics of this helmet allows that without too much drag and so does the helmet of Ives Rossy. Thus design is crucial for someone who wants to build a high quality wingbody with good ergonomics that can enable longer flights. The second important thing is the propulsion element, its position and whether it has thrust vectoring. The Switchblade Phasst was simply badly designed and so was the Homo Volis, they had too many elementary design flaws to become successful.

    Felix Baumgartner went the other way, he applied the KISS principle, Keep It Simple and St...Straight-out. He designed the Gryphon Wing with a low AR but compensated that with good flying controls. Allow to use the speed for better handling. He knew that he can't get a wingbody to fly both slow and fast without sophisticated aerodynamics knowledge so he designed the wing for high speeds and controls which can do good at velocities close to terminal. And voila, he did great, flew across The Channel. There are other wingbodies people designed, some with more success and others (majority) with less. But the basic principle still applies, if you want to fly both slow and fast (or superfast) well - the design gets complicated.

    Indeed. But what people often neglect is the human cardiovascular system. When positioning the elbows out the proposed way - the pressure lays on the arm arteries. The circulation in the arms gets problematic even without high G loads and soon the pilot start feeling arms 'fading' and hands becoming numb. This is the least desireable effect, to enter a high G load maneouver and not have the necessary strength to get out of it due to not enough blood in the muscles. There are ergonomic solutions for this but these are details beyond the topic of the thread.
     
  16. Sep 28, 2015 #36

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  17. Sep 28, 2015 #37

    Retroflyer_S

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    This has to be researched and studied.
     
  18. Sep 28, 2015 #38

    RPM314

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    How do you plan on getting a test pilot?

    cessna_pilot.png
     
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  19. Sep 28, 2015 #39

    DangerZone

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    Are you kidding..? :D

    In most cases when well designed and built experimentals are in question, there are a lot of pilots who would like to try it. ;)

    It's like asking how would you find guys for free testing of your pimp friend's new hooker that just turned 18 and wanted to be a porn star her whole life. Are you sure there would be no candidates to fullfill her dreams? :gig:
     
  20. Sep 28, 2015 #40

    bmcj

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    Well, since you put it that way...
     

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