Roadable aircraft

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Topaz, Jun 30, 2006.

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  1. May 16, 2013 #601

    jtrealty

    jtrealty

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    Hello All
    I have been a lurker for a while. I have also been interested in designing and building a flying car. I say flying car because IMHO a roadable airplane is never going to be popular. It sounds like an airplane that can be towed on a road. Some of the necessary attributes of a flying car that would be successful include:
    It has to look good
    It has to have at least 2 seats (dual controls for flying and instructing) and room for some limited baggage
    It has to be easy to drive and fly
    It has to have about the same range as a car AND a small airplane and similar speeds
    It cannot cost more than a very expensive car AND a very expensive small airplane
    It should fit into a typical garage
    It cannot take a long time to convert between modes, it can be done manually but it must be idiotproof.
    All the talk about infrastructure isn't important. If flying cars ever becomes popular that will follow. When cars were first built there were no roads or gas stations. Same with the legal issues. If flying cars become popular that can all be worked out. Those are manmade problems and can be solved with manmade solutions. It is the engineering problems that must be overcome. I am still investigating different planforms and power plants and still have not been able to pick any particular direction. As we all know that is a VERY important step since it determines everything. I do know rotating wings, gyros and helicopters, are too hard to fly and too mechanically complex and dangerous to people nearby on the ground when landing or taking off. Parasails are too slow for the airplane mode. 3 wheels won't cut it either. That isn't a car by anyone's standards, it is just a technical way around car safety requirements. It would seem STOL or VTOL would be a very desirable feature. My approach is to find what would be desirable in the marketplace and then try to create such a product. Not the other way around. If what you build has no market you could never be successful. I look forward to your comments
    David Teitelbaum
     
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  2. May 16, 2013 #602

    jedi

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    David Teitelbaum,

    Jim Milner is fairly close to you and has hardware you may be interested in or at least may comment on.

    I agree with your comments in general. I think on common error is to attempt too much performance from the aircraft side. It is easy to write high expectations that are difficult to meet. The first car only went 10 to 15 mph and not very far but it worked. Once you get a working prototype the performance can be improved over time. This is especially true for range. I could be satisified with 200 to 300 mile range if I could drive to a gas station and not have to buy avgas.

    Conversion from road to air needs to be quick and easy, eventually, otherwise it is easier to drive than convert and fly.
     
  3. May 16, 2013 #603

    henryk

    henryk

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  4. May 16, 2013 #604

    jtrealty

    jtrealty

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    While the prototype or "Proof-of-Concept" vehicle may not be required to have a lot of range or performance, what is offered to the marketplace must be better than what is offered currently or it will have a very small market. Because you will be competing with products already in the marketplace, (mature technologies) you must be able to offer something you cannot get now. It has to be more than just a novelty. For instance, if Moller's car could actually fly it would sell. Too bad it can't do either. The TFX just doesn't look like a car, that is one of it's biggest drawbacks. It looks like a scrunched up airplane. People want what they see in the movies, for example, the cars in the Fifth Element. Those would sell like hotcakes. In engineering there is a point where it has to look as good as it works, that's how you know when you are getting close to your ideal. Where is Jim Milner and what is he working on? What hardware does he have? To start a project like this you really should start on a blank slate and not use what is handy but you should strive to use as much off-the-shelf technology as possible.
    David Teitelbaum
     
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  5. May 17, 2013 #605

    henryk

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  6. Nov 5, 2013 #606

    craig saxon

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  7. Nov 5, 2013 #607

    bmcj

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  8. Nov 6, 2013 #608

    Aircar

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    I doubt these powered parachutes are going to be 'road-able' in too many jurisdictions and are basically too slow to be useful as aircraft --if flight speed only matches typical headwinds then you are going nowhere . I have come across several more 'new' roadables but in each case they amount to only hyped up graphics and 'one more for the pile' with little or no engineering value for a technical forum --one is a direct copy of the Waterman Arrowbile with a clutzy tandem seated car body and another is a very vestigially winged contraption using 'wingrid' style louvered surfaces with an aspect ratio of about four. Whether public announcements of the 'flying car has arrived at last' amount to just more 'crying wolf!' or serve to keep the idea in the consciousness is hard to say --I note that the Slovak (Klein) Aeromobil has made it onto an AAP link and gets a mention in several Australian newspapers --first flight etc .
     
  9. Nov 6, 2013 #609

    henryk

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  10. Nov 8, 2013 #610

    Aircar

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    Interesting to see competition starting in the powered parafoil world --looks like the "red Bull' sort of inflated cones in use although a bit tamer flying . The sort of daily use 'minimum' aircraft to carry one person and hand luggage or a backpack --(the sort of thing you can carry on a train or bus or from a car to the workplace as commutters are able to carry now) might be very much like a parafoil in terms of minimum speeds to take off and land and the relative safety to those below and the users. The case to allow this general type of flying machine to operate over suburbia and for everyday transport will be contingent on establishing a high level of reliability together with a 'tolerable' worst case scenario (for example if mid air collision or pilot incapacitation occurs or just running out of fuel --the 'what happens next?' question --it the answer is just a slow motion flop onto the roof or gardens below then it may well be able to get approved and accepted as a real means of transport . They may not be "ROADable' in the strict sense but might be 'footpathable' or 'parkable' and walk to the destination so achieving the same end result --if so this sort of thing has a place on this thread in the spirit of usefull mobility by air.
     
  11. Nov 8, 2013 #611

    henryk

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  12. Nov 8, 2013 #612

    bmcj

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    I wonder, can you make a faster PPG by using a much smaller sail with higher wing loading, and still be controllable?
     
  13. Nov 8, 2013 #613

    henryk

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  14. Nov 9, 2013 #614

    oriol

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    Speed flying - Wikipedia, the free encyclopedia

    A speed riding wing has half the surface of a standard paraglider wing, it´s much smaller glide ratio makes them more suitable to fly close to the slope of the mountain with the pilot wearing skis like in this Whoopy fly video.

    [video=youtube;8hlRTAisMeg]http://www.youtube.com/watch?v=8hlRTAisMeg[/video]


    I bet that those modern wings like the old first paragliders (with a very poor glide ratio) were primarly designed for hiking (because of their small dimensions/weight) so that after climbing the mountain the hiker glided back to the base of the mountain. It doesn´t seem to be as risky as base jump but still the wing is much more nervous than a standard paraglider: the landing speed is much higher, some experienced paragliders have had accidents with them.
    According to wikipedia: "Sustained flight with a speed glider is possible over a ridge in strong winds."


    Oriol
     
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  15. Nov 9, 2013 #615

    henryk

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  16. Nov 10, 2013 #616

    henryk

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  17. Jun 8, 2016 #617

    ProfessorRooster

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  18. Jun 8, 2016 #618

    henryk

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  19. Jun 8, 2016 #619

    narfi

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    henryk!
    I like the idea behind a flying hovercraft but have not found much information through google. (some mention of testing with Lake aircraft but no real information)
    I tried reading the google translate of the forum thread you posted but the translation was poor and I had a hard time following it, (discussion of where a dog is buried and what Everest is)

    I think I read that they had some 'fix' figured out for ground stability in crosswind situations, but could not figure out if they ever said what that was.

    Do you have any more information (or more recent information) about this project or projects like it? Any videos or data for such projects?

    Thank you :)
     
  20. Jun 8, 2016 #620

    henryk

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