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Thread: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

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    Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    Hi all, I'm new to aircraft construction, but I've built motorized bicycles before, and am taking a class about building frame structures and can do engineering calculations when given the forumlas, and am a fairly skilled woodworker/mechanic, and am going to be taking welding this summer.

    I'm thinking I might want to possibly get a sport pilots license or at least build an ultralight of some sort for recreation and somewhat practical transportation (Go Island Hopping, Fly cross country to my friends who normalli I have to drive to, Fly out to cape cod in the summer, etc...)

    I have no aviation experience, so, what would you guys recomend I work with?

    I'd like to make a design baded roughly off a hiller flying platform (the things that look like UFOs from the 50's) for propulsion with two ducted fans (rotating in opposite direction to balance torque) side by side with a controll system to tilt the whole system any which way for controlled low speed flying, hovering, and vertical takeoff. They could tilt forward once in the air slowely, and a pair of short winglets could generate lift like a normal plane.

    Do you guys think this could work? Also what are the restrictions about parking/flying ultralights in towns and such? Like not buzzing low down, but it it possible to use a an ultralight rotocraft practically?

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    Moderator Dana's Avatar
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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    You mean like this?


    The short answer is that what you propose probably isn't feasible. Although a very few ultralight helicopters have been flown, VTOL and ultralight really don't mix. The contraption pictured above (which they've spent millions on without any real success) isn't an ultralight. Ducted fans are terribly inefficient for direct lift or any other slow speed applications, and it would be very difficult to make a VTOL ultralight with any useful range.

    Also "short winglets generating lift like a normal plane" would mean it's way too fast to be an ultralight or even a Light-Sport Aircraft (LSA).

    Don't count on an ultralight for practical transportation; besides the limited range there are also weather issues. With a SP certificate and a LSA it gets a bit more practical, but you can still be tied down by weather. Also with ultralights, or any aircraft with a 2-stroke engine, a good rule is not to fly farther over water than you're willing to swim.

    Regarding restrictions, you can't fly an ultralight over "any congested area of a city, town, or settlement". In more open areas, it depends on local zoning or other ordinances.

    I see from your profile you're in Boston; I believe there is a fairly active ultralight group in Shirley, MA, you might want to stop there and check it out.

    -Dana

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    Registered User BBerson's Avatar
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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    No person has ever built a successful VTOL as far as I know. Yes military funded VTOL's are numerous, but no private VTOL.

    Someone with no aviation experience would have much to learn.

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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    Quote Originally Posted by BBerson View Post
    No person has ever built a successful VTOL as far as I know......no private VTOL.
    Excluding helicopters and hot air balloons, of course.

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    Registered User BBerson's Avatar
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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    Normally when someone is talking about VTOL aircraft, ordinary helicopters and balloons are excluded.

    Some of the stranger helicopter variations such as convertiplanes and compound helicopters are sometimes included in books about VTOL's but plain jane helicopters are not.

    Of course all helicopters are capable of VTOL flight but they are called helicopters, not VTOL in the industry.

    VTOL = Vertical Takeoff or Landing

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    Registered User bmcj's Avatar
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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    Sorry BB, I didn't do that to point out any errors - you were correct in your statement. I only put that out there to clarify it for any newbies that might not know.

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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    OK...in that case, what is the cheapest, most practical way to get off the ground?

    How are gyrocopters for beginners? As far as ease of flight, safety, take off/landing, making amphibious, etc...

    and PS, I don't mind swimming :P Thought is is this because of poor reliability or because they just don't like seawater?

    Also I take it there is nothing that is like a mini version of this: http://en.wikipedia.org/wiki/Tiltrotor
    Last edited by Lorena Palind; February 3rd, 2010 at 07:54 AM.

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    Moderator Dana's Avatar
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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    Sorry, no ultralight tilt rotors.

    The cheapest way to fly is a used ultralight. Short on practicality but long on fun. Used ultralights for under $3000 are common, and occasionally they turn up for free. Have to be careful though, some (not all) older designs should be permanently left on the ground.

    Gyros are more complex and require more maintenance. They often need more space for takeoff then airplanes but can land almost anywhere.

    As for swimming, well, it's tough to do when strapped into an aircraft (don't ask how I know). With a 2-stroke engine, it's not a matter of if the engine quits, but when.

    -Dana

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    Registered User bmcj's Avatar
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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    You are correct... there are no miniversions of the tiltrotor, unless of course you consider (wait for it...) the Moller Aircar (the crowd boos loudly and begins throwing stones!)

    There are several members from Australia and New Zealand that have posted some impressive videos of gyroplanes (or autogyro, if you prefer; gyrocopter is a throwback term from the Bensen days and has fallen into disfavor). Personally, I like the Littlewing gyro concept for safety and stability, but others would argue that the pusher versions are just as safe. Here's a link to the Littlewing site:

    Little Wing Autogyros, Inc..

    Bruce

    Disclaimer: I am not a gyro pilot, so I can only speak from a second-hand perspective.
    Last edited by bmcj; February 3rd, 2010 at 12:14 PM.

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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    Quote Originally Posted by Dana View Post
    -Dana

    The problem with telling a Lawyer joke is that lawyers don't think it's funny and the rest of the people don't think it's a joke.
    Hey, that sounds familiar

    http://www.homebuiltairplanes.com/forums/new-member-introductions/5955-hi.html#post49087

    Also, as Starman pointed out, "99% of lawyers give the rest of them a bad name".

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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    Don't look for it at your supermarket any time soon, but a long term project I am developing is the 'Ultralight' Tiltrotor. It won't be an ultralight, except compared to a V-22 or an XV-15, but it should have an empty weight of less than 600 pounds. Below is just a conceptual study. I intend to use two ~100hp Tiernay turbine engines I have which are cross-linked for single engine ops, and it should be fully autorotatable.


    -Christian

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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    QUOTE=Lorena Palind;62286]OK...in that case, what is the cheapest, most practical way to get off the ground?

    How are gyrocopters for beginners? As far as ease of flight, safety, take off/landing, making amphibious, etc...

    and PS, I don't mind swimming :P Thought is is this because of poor reliability or because they just don't like seawater?

    Also I take it there is nothing that is like a mini version of this: Tiltrotor - Wikipedia, the free encyclopedia[/QUOTE]
    Two stokes run when they want to not when you want them too. I've kicked around a tilt rotor well tilt wing needs a lot of power tho.

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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    Quote Originally Posted by Lorena Palind View Post
    OK...in that case, what is the cheapest, most practical way to get off the ground?
    JUMP!


    Quote Originally Posted by Lorena Palind View Post
    How are gyrocopters for beginners? As far as ease of flight, safety, take off/landing, making amphibious, etc...
    I'd read through some of the posts in this sectiojn of the forum:

    Rotorcraft

    You'll find some posts by gyro pilots (many in Australia) and also some neat videos. Post this same question about gyros for beginners in the rotorcraft subforum and you'll probably get an answer from them.

    Also, there is a good discussion in this thread:

    http://www.homebuiltairplanes.com/fo...html#post49948

    (The link takes you to the 12th post in the thread because you start seeing some videos at that point, but feel free to read from the first post.)

    Bruce

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    Registered User Joe Fisher's Avatar
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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    The idea of gyro flight has always intrigued me. In the 1950 I was about 10 I sent off for the Benson plans and of coarse nothing ever came of that. I learned to fly airplanes in Idaho in the 1960s and almost every hanger that I went into had at least one gyro but I never saw one fly.I thought it was funny in 1969 I went to the EAA fly in at Rockford. I don't know the actual numbers but it seems there were about 600 experimental aircraft there and it seemed like about haft were gyros. The only one that flew was Benson during the afternoon airshow all the others just sat. In 1980 I operated the Washington Mo. airport flight instructed and A&P work. There was a grope of gyro people that would camp out on Saturday nights and fly on Sundays. There leader was a gyro CFI and they mostly trained in a gyro glider towed behind a car ect. There were about 7 or so engine powered gyros but the only one that flew was the instructor the others would taxi and if they lifted off they would always crash. They were a dedicated bunch.

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    Re: Would it be possible... (twin tilt ducted fan ultralight w/short wings)

    A homebuilt tilt rotor project would be an act of hubris. Perhaps there are non-technical reasons why tilt rotors, though they've been in development for 40 (I remember pictures back then) or more years, are not yet used much, but I bet there are many technical hurdles.

    If you really had to build something, a Skypup is pretty minimal, and many have been built. They seem to have a decent reputation. But if you're a large person, it's probably not a good idea. Probably there are other ultralights that are also easy projects. But easy in this context is a relative thing. It's going to take you a long time.

    LSA sounds like a better idea if you want to get someplace, but that makes the budget go up. I'm curious myself as to what's the quickest building experimental, minimalist LSA.

    BTW, there is a fairly active group of "trike" fliers in Stow, MA, at a place called Crow Island. There's a Yahoo group or something. I often see them fly overhead. Or at least I think that's where they come from and I know they were flying from there a couple of years ago because I dropped by. If you can't find the Crow Island people on the web, try the URL below. You can get there on the Assabet River Trail from Winter St. or White Pond Road, but I think there's a locked gate so you might have to walk or take your mountain bike. But they don't like people walking around unless you introduce yourself. They tend to fly on calm, warm evenings.

    http://tinyurl.com/yh3nabo

    or

    http://maps.google.com/maps?q=stow,+...16372&t=h&z=16

    As you can see, there's LOTS of room and a guy used to fly a regular airplane out of there. Then again, I'm told a guy used to fly a Luscombe out of here: stow, ma - Google Maps And his son still flies an ultralight there.I hope these links haven't been mangled!

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