Too hard to attempt?

[jnida63]

Watching the history channel on old russian secret aircraft got me wanting to build a new plane.

It never flew but looks really sweet.

[Sparky Paul]

It would fly.
And it would be unique.
Normal precautions on the c.g... about 30%.

[Accu157]

floatplane?! :eek:

[nmasters]

submarine

[BMatthews]

I want to be there to film the looks on the scale judge's faces when it skims in for a landing and then just keeps settling and settling and settling and settling and settling and settling and settling until all that's left is a little periscope running around.... :D

[vintage1]

That would fly allright..but it would be too light to sink..unless it was deliberately flooded..

The tail is very small..CG at 20% or less I'd say..make a chuck glider first to get that right.

[Work in Progress]

It really wants a bit of reflex in the rear fillety part of the wing. The pic makes it clear there isn't any, but since I am almost certain this never flew full size I wouldn't let a little thing like cheating the airfoil stop me making a model of it.

[jnida63]

Here is a short clip from the show i compressed it alot to make it manageable.
It was supposed to be a float plane that converted into a sub with 2 torpedoes.

http://www.rcgroups.com/forums/showthread.php?t=631113#post6786537

[BMatthews]

I remember reading about the old pre nuclear submarines that the biggest problem they had was making a submarine heavy enough to sink. I know it sounds odd but it's the reason that the old WW2 subs were extremely crowded inside so that they would carry a minimum of air volume. This changed somewhat with the nuclear designs as they have a LOT of heavy sheilding to protect the crew.

A sinkable airplane would suffer from much the same issues. To keep it light the crew compartment would need to be small and even the fuel tanks are an issue. Gasoline is lighter than water and the empty volume in the tanks that holds air would make it that much harder to sink. Pretty much the entire craft above the floats would need to be free flooding in order to be able to sink and the floats would need to be sealed and floodable but would also be the ballast tanks.

In interesting design concept for sure.

[Mister UHU]

Proof there was LSD in the USSR !!!

Yeah, try it, but if you are going scale,
I can't believe you will be able to get much original source material about the project.
It must have been about 50 years ago at least.

Was it actually supposed to fly, or was it just a bizarre submarine ??

If it was a plane/submarine, then I think the submarine part is harder.

The drive would need to be watertight.
Most electric motors and ESCs need air cooling,
if they are sealed in this won't happen.

The RPM and prop needs of water and air are so different, gearing might be needed.

I think trying to get it up to speed underwater to fly out of the water would be impossible.
It would have to take off from the surface like a float plane.

As others have posted, ballasting is a problem,
I think most model subs use compressed air tanks, or water pumps.

Maybe there might be a kit sub you modify or use parts from,
but this project looks difficult, I think you will need a lot of patience and creativity too.

I can't of any proven examples of such a combination,
I think some searching might save a lot of time and hassles.

If you do succeed, then I'm sure it will become well known.
The foamy hydro thing is slightly similar, but much, much, technically easier.

Somebody has to be the first, it might as well be you.