LSA amphibian concept - a modern-day Shavrov?

[cluttonfred]

I recently came across the little Shavrov Sh-2 amphibian, widely used in the Soviet Union from the 1930s to the 1960. The Shavrov was in many ways the amphibian counterpart to the ubiquitous Polikarpov Po-2 biplane.





Since there are so few LSA amphibians, and almost none for plans building, I got to thinking that the Shavrov might make a great inspiration for a modern light amphibian. I am thinking of a plywood hull, aluminum-tube-and-fabric wings and tail surfaces, maybe Oratex fabric covering, 2.1 liter VW power (Aerovee, Great Plains, etc.), wood prop, hand-cranked (or lever) gear. The goal would be to keep it simple and light, ideally under 495 kg/1090 lbs gross weight to keep within the European microlight limits.

What do you think...something that our members would be interested in building and flying?

Cheers,

Matthew

[Floatsflyer]

Except for the open cockpit, it looks very much like a Kingfisher which is available as a plans built and you could modify. Not sure though if it meets LSA eligibility.

[cluttonfred]

Thanks, but both the Anderson Kingfisher and the Volmer Sportman are listed at 1500 lbs gross weight, so too heavy for LSA and much too heavy for European microlight. LSA max gross weight with floats (which presumably applies to boat hull flying boats and amphibians as well) is 1430 lbs, so presumably either one could be custom built to LSA specs but existing planes aren't included. I had in mind something quite light that would meet European microlight limits, so well within LSA regs. Cheers, Matthew

[cluttonfred]

I still have amphibians on the brain...here is an even better video clip of the Shavrov Sh-2 in action.

[Floatsflyer]

I still have amphibians on the brain...

Welcome to the club, it's an affliction for which there is no known treatment. A huge part of my brain and heart is emotionally attached to amphibs and flying boats. We are in very good company though. Some of the all-time greatest aircraft designers, developers, builders and aviation advancers were hooked on them. Mr. Boeing, Mr. Curtiss, Mr. Martin, Mr. Short Brothers, Mr. Saunders, Mr. Sopwith, Mr. Jaun Tripp, Mr. Sikorsky, Mr. Dornier, Mr. Hughes, Mr. A.V.Roe, Mr. Mitchell just to name a few.

When I first saw the only flying Sikorsky S-39 left in the world at Osh, I couldn't take my eyes away. After a few days of begging, the owner Dick Jackson finally relented and let me sit in it. Afterwards, I had dilusions of grandeur and began thinking about the possibility of scaling it down to S-LSA size and manufacturing replicas. I thought the combination of design grace, style and beauty, and the golden age of aviation nostalgia would be a sales winner. Alas....perchance to dream.

If you're better suited to building than I am, there are meticulous scale model S-39's available that could be adapted to LSA size plans.

http://www.classicaero.com/s-39/

http://www.internetmodeler.com/2003/...ks/CMK_S39.htm

[cluttonfred]

I wouldn't be interested in an authentic replica of the Sikorsky (or the Shavrov, for that matter) but I would certainly consider the Sikorsky layout if tackling an LSA amphibian. One solution, which would still suit my preferred plywood hull/aluminum tube and fabric construction method, would be something like a cross between the Sikorsky and the Ramsey (not Dormoy) Flying Bathtub.

[rwanttaja]

I recently came across the little Shavrov Sh-2 amphibian, widely used in the Soviet Union from the 1930s to the 1960. The Shavrov was in many ways the amphibian counterpart to the ubiquitous Polikarpov Po-2 biplane.

Since there are so few LSA amphibians, and almost none for plans building, I got to thinking that the Shavrov might make a great inspiration for a modern light amphibian. I am thinking of a plywood hull, aluminum-tube-and-fabric wings and tail surfaces, maybe Oratex fabric covering, 2.1 liter VW power (Aerovee, Great Plains, etc.), wood prop, hand-cranked (or lever) gear. The goal would be to keep it simple and light, ideally under 495 kg/1090 lbs gross weight to keep within the European microlight limits.

Well, since the Sh-2 has a gross weight nearly twice your desired limit, we couldn't use it for help, much.

But I think what you're talking about is do-able. You probably remember the Two Wings Aviation Mariner; a biplane ultralight of pretty much the same configuration.

http://www.lightsportaircraftpilot.c...r/153_5394.JPG

With the additional slack given by the European limits, you could probably come up with a single-wing two-seat variant. To save design time, you could probably even adapt the wing design from a Pietenpol or Fly Baby.

I'm not sure how much overall interest there would be, but it sounds like a great personal project.

Ron Wanttaja

[cluttonfred]

Thanks, Ron. I am not looking to replicate any historic design, just casting around for inspiration in terms of configuration and options. I think the European microlight weights are doable, but they are certainly limiting. The 495 kg MTOW European microlight limit appeals to me because it forces the weight down to the point where an inexpensve 75-80 hp VW, with a climb prop to be sure, becomes a viable option.

Yes, I do remember the Mariner, even saw one as Oshkosh last summer. I would love to see one painted up as an RAF or FAA Supermarine Walrus. What struck me about the Shavrov is that, despite dating from 1929, like the Pietenpol, the hull/fuselage is actually quite sleek. I can easily see a new design in the same spirit but with a neat cabin or canopy which would seem quite modern and provide useful performance not available in any design today.

As for the market, I really don't know what would make the most sense--microlight, LSA or regular experimental, amateur-built. The latter option would allow a two-/three-seater able to carry a third person OR lots of camping and fishing gear for back-country adventure but would require a more powerful and expensive engine and would become quite a different aircraft.

Personally, I have always been attracted to boat-hull amphibians but there have been so few options, and the designs so old and little supported, that I have turned my focus to other types. Perhaps a succesful, affordable design with active support would help revive interest in the type?

Well, since the Sh-2 has a gross weight nearly twice your desired limit, we couldn't use it for help, much.

But I think what you're talking about is do-able. You probably remember the Two Wings Aviation Mariner; a biplane ultralight of pretty much the same configuration.

http://www.lightsportaircraftpilot.c...r/153_5394.JPG

With the additional slack given by the European limits, you could probably come up with a single-wing two-seat variant. To save design time, you could probably even adapt the wing design from a Pietenpol or Fly Baby.

I'm not sure how much overall interest there would be, but it sounds like a great personal project.

Ron Wanttaja