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Inexpensive homebuilts for sport pilots, design contest?

Posted By:
Matthew Long
Homebuilder or Craftsman
122
Posts
12
#1 Posted: 3/8/2010 17:36:22

 There seem to be very few ready-to-fly or kit Light Sport Aircraft aiming for the low end of the price range (lots of Porches, few VW Beetles).  For building from plans there are certainly many old designs that qualify--Eric Clutton's FRED, for one (that's my site)--but few if any new designs.  I think we are missing out on inspiring and recruiting a whole new a new generation of homebuilders.  Where are the Pietenpols and Volksplanes of the 21st century?

One thing that might help is a design contest aimed at simple, inexpensive homebuilts for sport pilots.  EAA used to sponsor design contests (IIRC, lots of great designs came out of those including the Fly Baby).  Given the state of the economy worldwide, now is a perfect time for EAA to take the lead in promoting low-cost flying options.

Cheers,

Matthew



******* Matthew Long www.cluttonfred.info
Michael Johnson
Homebuilder or Craftsman
90
Posts
30
#2 Posted: 3/8/2010 19:15:48

Absolutely!!!! Count me in!!!

For the last two years I have been developing an airplane that fits it perfect. It's a design that's like nothing else ever tried or developed. The airplane brings a new meaning to the words "open cockpit".

Imagine an airplane fuselage that ranges between 3" and 1/4" wide. I got the idea after looking at an RC airplane that's basically made from thin foam, say 1/8" thick. The seat is wide and is totally sculpted to fit the entire body, legs and all.

The wings are folding and a small center section(24") is seamlessly molded into the thin fuselage. The wings connect to an aluminum shaft that has a 7 degree taper and a locking devise that is always pulling it into tension. A simple lever hinges up 6" to lock and release. The ailerons function off an internal hollow splined shaft that slides along with the wing. When the pilot wants to fold the wings for transport you simply pull a safety pin, pull up on the handle, walk over to the wing tip and pull. The wings should slide with absolute precision then fold back into the fuselage. It's nice because having the fuselage so thin, even with the wings folded it's still thinner than any airplane available....by a long shot!!

The construction is simple because the builder starts out with a flat sheet of 3/4" foam. Then a template is set on top, drawn, and cut with a steak knife. The entire fuselage should be able to be built (foam only) in 1 day. The entire fuselage should be able to be completed in a week not including finishing and paint.

The landing gear is a taildragger and the front gear was designed using Sonex tubes fitted into a carrier that is also thin and branches up to hold the engine.

It's basically like a motorcycle for the sky but even thinner.

I have completed a lot of drawings and some models so far. I have also done some test pieces.

My current project is a Stits Playboy so I only work on it once in a while.

MJ

 

 

 



Tom Hackel
Homebuilder or Craftsman
126
Posts
22
#3 Posted: 3/8/2010 20:32:52

I'm up for giving it a try, the EAA would have to write the disclaimer for liability.

The rights to the winning A/C design could go to benefit, one of the EAA programs. (Need an even trade, so to speak so you wont get killed with taxes and they get something for it. ..... Something would also have to allow and state an amateur/ experimental design.)

Just addressing concerns. Now scratch your brains and draw something  biggrin

Tom

 



Michael Johnson
Homebuilder or Craftsman
90
Posts
30
#4 Posted: 3/8/2010 21:04:19

What if a bunch of us got together online and decided exactly what our goal was. Then, in groups of a bunch of groups of say 5 people each attack a component of the airplane. Like 5 people work on the tail design, 5 people work on the fuselage design, 5 people work on the landing gear, and so fourth. These 5 groups develop it from start to finish and together they vote and and determine the direction and final product. All this is then connected together and testing is then done.

When it's all done the plans are available for free on a PDF.

I'm willing to bet if a bunch of us got together and started a thread just on a landing gear design we could all come up with some great ideas. And people who don't want to be part of the design process would still be able to watch, learn, and be part of something great.

It all starts with, "what would be the ideal airplane" that meets certain criteria, and what is the criteria. I bet as a group this would be simple. Back in the old days people did it by themselves and had to mail letters. Now we have technology to help us so we really have no excuses.

Just my two Yen

MJ



Tony Scholes
15
Posts
6
#5 Posted: 3/8/2010 21:49:33

An inexpensive open-source airplane?  Great idea, count me in!



Michael Johnson
Homebuilder or Craftsman
90
Posts
30
#6 Posted: 3/8/2010 22:34:09

Yeah, lets start a thread and push forward.



Grant Smith
Homebuilder or Craftsman
135
Posts
7
#7 Posted: 3/12/2010 00:26:37

For true VW like characteristics and low cost it should conform to FAR 103 requirements.



Grant Smith CFI
Tom Hackel
Homebuilder or Craftsman
126
Posts
22
#8 Posted: 3/12/2010 06:48:14

Grant, don't make me read it..... I've been away and driving.

E-LSA / LSA  2 seats, 1320 max load and that line.



Tom Hackel
Homebuilder or Craftsman
126
Posts
22
#9 Posted: 3/12/2010 07:14:53
Thomas Hackel wrote:

 

Grant, don't make me read it..... I've been away and driving.

E-LSA / LSA  2 seats, 1320 max load and that line.

 


tongueout Grant, it's morning and you made me open BOTH eyes!!!!!  Just foe reference That Is a REALLY BIG CANON.

The ultra-lites do have a place in my desire list ..... about #4.

I am Looking more at the LSA category.......

Submissions for each category because we have a diverse group may be called for.

Tom



Lincoln Ross
53
Posts
5
#10 Posted: 3/12/2010 20:36:32

If performance matters more than looks, then I suggest you all read Wainfan's PAV report at the Facetmobile site. Very interesting stuff. He makes a convincing case that you can make a safer, simpler, lighter aircraft with less labor, out of flat structural panels. Or, for a homebuilder, perhaps riveted tubing a la Facetmobile. The structural panels idea, I think, might lend itself to a "Smoothmobile" without too much trouble if the outer panels were fairly thin.

His PAV would outperform a 152 on 80 hp (instead of 110), have very benign stall, and gobs of room inside. I recall the useful load was above 500 lbs.  I'd say it was vaporware if it was coming from someone else and a smaller prototype had not flown. The Facetmobile did 110mph and 750 fpm with useful load of 250 lbs and horsepower in the 40's. Empty  weight was only 370 lbs. Wainfan didn't discuss this, but from a lecture of his it sounds like the plane was spirally stable. It would fly as slow as 33 knots, which might be nice if you had to land in a bad place. (And he did, which is why it's not in the air right now.) Also a lot of airplane in front of you and to the side if you hit a tree. If it was SUFFICIENTLY spirally stable, that probably means that you could fly into a cloud and come out the other side without instruments if you didn't do anything super dumb.

Anyway, I think that, unless it's too ugly, this would be a very promising approach. And I think the smoothmobile version wouldn't be ugly.

-----------------

I just had an idea recently for a 103 compliant aircraft that ought to be very light and fairly easy to construct, but I'm keeping it under my hat for now. Inspired partly by the Skypup.

 ------------------

Michael:

I hope the airfoil is not flat like on those foamies! That would probably generate only half the lift a regular airfoil would, and it would be structurally very weak unless you braced it with a gazillion wires.  I think you might want to go a bit wider on the fuselage, or use an aluminum rectangle as the S2 motorglider does. The rectangle has a nice feature that it kind of lays out the whole fuse and you can bolt all the components to it. Have you seen the Cloudster ultralight? Has some features in common with your design.

 



Randall Poet
Homebuilder or Craftsman
4
Posts
0
#11 Posted: 3/16/2010 22:38:40

I really hope this takes off, hoepfully in several directions. 

Personally, I need to see something that has some real ceiling to it, say a capability of 16000' or so.  Preferably with 2 200 pounders and a bit of luggage.

--Randy



Michael Johnson
Homebuilder or Craftsman
90
Posts
30
#12 Posted: 3/16/2010 23:43:06

I hope so too! The best thing to do is keep talking and generating ideas. It has no right or wrong answer, Go over the posts and you can already see progress. Any idea is a good idea!

MJ

 



Jim Hann
Vintage Aircraft Association MemberHomebuilder or CraftsmanAirVenture Volunteer
125
Posts
41
#13 Posted: 3/17/2010 22:10:00
Matthew Long wrote:

EAA used to sponsor design contests (IIRC, lots of great designs came out of those including the Fly Baby).  Given the state of the economy worldwide, now is a perfect time for EAA to take the lead in promoting low-cost flying options.

Cheers,

Matthew

 

Matthew,

What other designs won the contest?  I was under the impression that the contest won by Pete Bowers was the only one they ran.

Regardless, I think that an inexpensive design would be good.  Pete talks about his own trials and tribulations in this article: http://www.oshkosh365.org/saarchive/eaa_articles/1962_12_03.pdf.  I'm sure that there are more articles about the contest in 1962 in the SA archives, I just didn't look for them, yet.

Jim



http://sites.google.com/site/jimscavaliersa1025/ http://picasaweb.google.com/CozyCanard http://sites.google.com/site/cavalieraircraft/
Tom Hackel
Homebuilder or Craftsman
126
Posts
22
#14 Posted: 3/22/2010 18:35:05

Randy, your going to want some air and presure at 16,000. Turbo or supercharger or both, http://www.deltahawkengines.com/

 

I have found scketching up some ideas helps. http://desktop.aero/appliedaero/preface/welcome.html

http://www.oriontechnologies.net/Documents/Airfoil.htm

http://www.engineeringtoolbox.com/air-psychrometrics-properties-t_8.html

 

These resorces may give you a start. I understand X plane 9 has a very good flight testing program, and will be a useful tool for testings plane and wing designs. I received my copy of the software today. $30. Now a to get controls.

 

Tom



Randall Poet
Homebuilder or Craftsman
4
Posts
0
#15 Posted: 3/24/2010 21:03:24

Thanks Tom.  WIll go through the links in more detail in a bit.

--Randy



Parker Woodward
17
Posts
3
#16 Posted: 3/26/2010 00:33:14 Modified: 3/26/2010 00:38:56

www.opengadget.net

If any of you engineering types want to use this site it is a good format for open-sourcing this project...or crowdsourcing it. It would be simple to upload parts and assemblies and in effect be able to collaborate on different designs simultaneously.

I am putting up our Ravin files and hoping our community of builders and the aviation community at large gets involved by submitting files for modifications, ideas, etc. that we may eventually produce and manufacture for kit buyers of the Ravin. If someone comes up with a good modification, then they get royalties. Pretty cool huh?