UFO- Useless Flying Object

Discussion in 'Hangar Flying' started by litespeed, Sep 27, 2016.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Sep 27, 2016 #21

    FritzW

    FritzW

    FritzW

    Well-Known Member

    Joined:
    Jan 31, 2011
    Messages:
    3,236
    Likes Received:
    2,855
    Location:
    Las Cruces, NM
    Me too! Except I'd go the "Nemeth Parasol" route.

    Neirrh Disk.jpg Neirrh Disk2.jpg



    Maybe recycle the One Tube Wonder idea and go for part 103

    2T Disk2.jpg 2T Disk3.jpg

    Disk is 12' x 14' with the axis moved 1' forward of the centerline. So ~132 sqft.
     
  2. Sep 27, 2016 #22

    BJC

    BJC

    BJC

    Well-Known Member

    Joined:
    Oct 7, 2013
    Messages:
    8,882
    Likes Received:
    5,735
    Location:
    97FL, Florida, USA
    Yes.

    Probably does - but if it does not, he can bust through 1/8" plexiglass with his head.

    People do, within their abilities, what they want to do. I'm guessing that he designed, built, and flew it because he wanted to, and that is what makes it, for him, better than a conventional design.

    As I stated in another thread, I prefer blonds. YMMV.


    BJC
     
  3. Sep 27, 2016 #23

    cavelamb

    cavelamb

    cavelamb

    Well-Known Member

    Joined:
    Nov 27, 2010
    Messages:
    297
    Likes Received:
    54
    Location:
    earth
    Those papers were written by Zimmerman himself!
    Nice find.

    20130817_114136A.jpg
     
  4. Sep 27, 2016 #24

    StarJar

    StarJar

    StarJar

    Well-Known Member

    Joined:
    Sep 6, 2011
    Messages:
    1,723
    Likes Received:
    402
    Location:
    El Centro, California, USA
    You fella's with modified ideas; note how he had his thrust line in the center of the airfoil. Thus minimal pitch changes, and also not asking the elevons for extra effort.
     
    Head in the clouds likes this.
  5. Sep 27, 2016 #25

    FritzW

    FritzW

    FritzW

    Well-Known Member

    Joined:
    Jan 31, 2011
    Messages:
    3,236
    Likes Received:
    2,855
    Location:
    Las Cruces, NM
    Nemeth-Parasol_2.jpg Not so much a factor if it's a parasol:


    103Disk2.jpg Maybe a little window in the front bottom of the pod (green thing in drawing)


    103Disk.jpg The model airplane guys get away with cutting a hole in the wing for the prop, I'm not sure how it'd work at this scale?
     
    Sockmonkey, cluttonfred and StarJar like this.
  6. Sep 27, 2016 #26

    BBerson

    BBerson

    BBerson

    Well-Known Member HBA Supporter

    Joined:
    Dec 16, 2007
    Messages:
    11,419
    Likes Received:
    2,094
    Location:
    Port Townsend WA
    That retracted gear made it look slick. Otherwise, the low aspect ratio with absurdly long gear legs looks rather insect like and probably a bunch of drag.
     
  7. Sep 27, 2016 #27

    Arthur Brown

    Arthur Brown

    Arthur Brown

    Well-Known Member

    Joined:
    May 1, 2016
    Messages:
    138
    Likes Received:
    15
    Location:
    London
    I rather like that idea! If the wing was thinned would if fly quickly with a 200lb thrust turbine?
     
  8. Sep 27, 2016 #28

    rotax618

    rotax618

    rotax618

    Well-Known Member

    Joined:
    Nov 1, 2005
    Messages:
    640
    Likes Received:
    214
    Location:
    Evans Head Australia
    I have seen David Rowe's previous 2 versions of his UFO at Narromine Fly-in. The UFO's have pretty remarkable and unique performance compared with conventional planform aircraft using a similar powerplant.
    David's aircraft have a very short T/O run, a quite high cruise (around 75 kts+) and an autogyro like landing approach and landing run. David also reported great stability especially in gusty and turbulent conditions.
    UFOs have a simple structure with a small number of components, could be made to fold into a very small package for storage or trailering, are stable and safe (will not stall or spin).Perhaps they would make an ideal candidate for 21st century Volksplane. Alas because they don't look "like a real plane" they are overlooked.
    The trick to the UFO performance is the "anomaly " of the behaviour of the vortex on lift on planforms with an aspect ratio of around 1.27 as observed by Zimmerman.
     
  9. Sep 27, 2016 #29

    Topaz

    Topaz

    Topaz

    Moderator

    Joined:
    Jul 30, 2005
    Messages:
    13,436
    Likes Received:
    5,132
    Location:
    Orange County, California
    You really want to hold a stick connected to a control surface in a highly pulsating airflow like that? "It's the new ACME Hand Massager! Wait, there's more!" ;)
     
    cluttonfred and bmcj like this.
  10. Sep 27, 2016 #30

    rotax618

    rotax618

    rotax618

    Well-Known Member

    Joined:
    Nov 1, 2005
    Messages:
    640
    Likes Received:
    214
    Location:
    Evans Head Australia
    I don't know why the stick would pulse, the tall tails on gyros don't cause the rudder pedals to pulse.
     
  11. Sep 28, 2016 #31

    TFF

    TFF

    TFF

    Well-Known Member

    Joined:
    Apr 28, 2010
    Messages:
    11,131
    Likes Received:
    3,016
    Location:
    Memphis, TN
    Prop in center. The thrust hits the cutout making the vibe. Also it is upper and lower segregation making it sound different. I have flown models with the engines in front. The last iteration we called pizza box. Flying stop signs and Gulf signs. They do not glide. Power off is not good. It flys enough on vectored thrust that it does not handle like a normal plane. Still cool but not a replacement.
     
  12. Sep 28, 2016 #32

    Aesquire

    Aesquire

    Aesquire

    Well-Known Member

    Joined:
    Jul 29, 2014
    Messages:
    2,242
    Likes Received:
    885
    Location:
    Rochester, NY, USA
    The tall tails on Gyros are centered in the thrust. Even on both sides.... although there is a difference top to bottom.... but the idea is cancel prop torque. You don't feel the tail trying to twist, the controls don't feed that back to the pilot.

    The Vought "flying pancake" did indeed crash ( engine failure, Icing? ) or more properly landed off field at a beach, braked hard to avoid people, and it nosed over onto it's back. The pilot simply exited the bottom hatch ( just like the UFO ) and funnily enough, Charles Lindbergh witnessed the crash and was impressed with the safety of the plane, and later flew it himself. I've often thought the V-173 would make a great replica build, possibly aluminum tube & gusset? But the twin engine or twin prop drive crank the complexity up enough to make me hesitant. OTOH, a pair of Rotax 582's and no effort to cross connect would work great on a lighter version, the original had no cross shafting, 80 hp engines and flew fine with one engine off.

    But the UFO is so small, so simple, it's very appealing.

    http://www.luft46.com/misc/sackas6.html
     
  13. Sep 28, 2016 #33

    Winginit

    Winginit

    Winginit

    Well-Known Member

    Joined:
    Jun 13, 2016
    Messages:
    811
    Likes Received:
    242
    Location:
    x
    Don't misunderstand me. Each of these things accomplished a designers purpose just like the UFO does for its designer. None failed to accomplish it's designed purpose, but to what end? If the designer only wants to build something for his own amusement and it performs as designed, then I congratulate him. If his purpose is just to prove it "Can" be done, then I again applaud his success. Myself, I'm more of a function over form kinda guy. The airplane appears to fly well in level flight and gentle turns. The shape or form of the wings appears to make downward sight lines difficult especially when landing. As I mentioned earlier, entering and exiting the airplane from below is somewhat difficult and dangerous if landing problems occur. To me the functionality of a clear line of sight and quick emergency egress would be far more important than the novelty of an uncommon form or shape. Remember, this is not just a difference in our appreciation of what the builder accomplished, but the fact that someone's life is at stake because of a design concession.I had a friend who died from burns suffered in a crash because he couldn't be extricated quickly enough. I would like it a lot better if the canopy opened instead of the fuselage bottom. Again, I respect what he accomplished, but it wouldn't be something I would ever consider building or flying.:)
     
    Last edited: Sep 28, 2016
  14. Sep 28, 2016 #34

    litespeed

    litespeed

    litespeed

    Well-Known Member

    Joined:
    May 21, 2008
    Messages:
    1,216
    Likes Received:
    184
    Location:
    Sydney
    I would think that David has accounted for the very unlikely event that it would flip onto its back by having the opening in the bottom.

    For a more traditional problem I think he is able to exit quickly via the top canopy. The reason for the bottom entry is purely for practical reasons of having to walk across such a wing and the height of getting in. The giggles of a bottom entry is just a bonus.

    I am sure David has thought of this emergency escape issue and planned accordingly.

    Also if carrying a chute and it all goes very bad- you can drop the bottom open and just fall out and away.

    David is a very cluey guy and has the benefit of lots of very experienced aviation specialist's around him in the war bird restoration game. I doubt he makes silly design mistakes.
     
    sotaro and FritzW like this.
  15. Sep 28, 2016 #35

    litespeed

    litespeed

    litespeed

    Well-Known Member

    Joined:
    May 21, 2008
    Messages:
    1,216
    Likes Received:
    184
    Location:
    Sydney
    Here is a earlier version- probably the mk11 UFO.

    You can see the top of the canopy is removable for safe and fast egress if needed.

    UFO-UL.jpg
     
  16. Sep 28, 2016 #36

    litespeed

    litespeed

    litespeed

    Well-Known Member

    Joined:
    May 21, 2008
    Messages:
    1,216
    Likes Received:
    184
    Location:
    Sydney
    Here is a better pic of his latest the MK5- the MK4 was never finished.

    Cruise is 85-90kts
    weight is 145kg empty

    You can clearly see the removable top to the canopy.

    ufo.jpg


    Benefits of the design are as follows
    1) Fly slow
    2) Fly stably at all speeds
    4) Be as efficient at the correct aspect ratio (1.25) as a higher aspect ratio (6)
    5) Land short with a parachute-like descent rate
    6) Take off in a relatively short distance
    6) Stall and spin resistant.

    So besides from been different it is a quite successful design- that has a good cruise but very low and slow ability.
     
    Last edited: Sep 28, 2016
  17. Sep 28, 2016 #37

    FritzW

    FritzW

    FritzW

    Well-Known Member

    Joined:
    Jan 31, 2011
    Messages:
    3,236
    Likes Received:
    2,855
    Location:
    Las Cruces, NM
    ...did he take any construction photos? I'd like to see the UFO in her birthday suit ;)
     
  18. Sep 28, 2016 #38

    litespeed

    litespeed

    litespeed

    Well-Known Member

    Joined:
    May 21, 2008
    Messages:
    1,216
    Likes Received:
    184
    Location:
    Sydney
    Sorry Fritz,

    I think his wife gets jealous as it is. She may get very upset if the world saw his other girl in the nude.

    No nude pictures are around that I know of.
     
  19. Sep 28, 2016 #39

    FritzW

    FritzW

    FritzW

    Well-Known Member

    Joined:
    Jan 31, 2011
    Messages:
    3,236
    Likes Received:
    2,855
    Location:
    Las Cruces, NM
    Oh well... I guess some things are better left to the imagination anyway.

    I wonder what would happen if I bolted a Mk5 (without the cockpit and engine) to the cabanes on the Neirrh and made a 3/4 scale Nemeth parasol :ponder: ...hummmm
     
  20. Sep 28, 2016 #40

    Aesquire

    Aesquire

    Aesquire

    Well-Known Member

    Joined:
    Jul 29, 2014
    Messages:
    2,242
    Likes Received:
    885
    Location:
    Rochester, NY, USA
    The same thing that would happen if you made 15 meter glider type wings & bolted them on. You'd have very different flight characteristics and probably need bigger tail feathers. ( I always advocate bigger tail feathers ;) )

    It seems the disadvantage with the very low aspect ratio wing is a higher induced drag at cruise. ( If I'm doing the physics right? )

    I very much like the gear retraction mechanism. Cables in a loop? Probably manual to save weight, 2 hand cranks?

    I would buy plans for that thing, just to put on the wall, even if I didn't build it.
     

Share This Page

arrow_white