submersible aircraft

[Stumble]

Just some hairbrained scheming from a non-technical person...

It seems to me that the biggest problem in converting from an aircraft to a sub is doing something with the wings. Since they will represent a huge amount of drag when submerged. The trick then would be to in some way have the wings collapse or disappear when in boat/sub mode. To achieve this I am wondering if it wouldn't be possible to use a fabric wing instead of a hard one. Think back to the old bi-plane era but use modern materials for the construction.

Maybe two or more carbon fiber guide polls running out from the body with carbon ribbing running on the polls. When the vehicle transitions to plane mode the poles are moved into position perpendicular to the body then the ribs are pulled into position through the use of lines to lock them into place out on the wing. The fabric stretches over the framework and off you go...

An easier idea would be to use a completely soft wing, with air pressure providing the rigidity to the entire structure. Though I have no idea the amount of pressure it would take to keep a wing stiff enough to carry these loads, though I suspect quite a lot. However this would solve any component storage problems.

[wardd]

registration, where, which?

[tspeer]

Originally Posted by Retired Geek

this was posted on their website today (flightglobal.com)

It only takes one look at the illustration to see how far off the mark it is. A submarine with flooded ballast tanks is heavier than water. The volume of the ballast tanks in the picture is not a large percentage of the total volume of the craft. That means that when the tanks are empty, the density of the craft will be not all that much less than the density of water. That's a very heavy weight to lift when trying to fly. But as it's pictured, the plane is much lighter and floats high in the water - when the tanks are flooded, it will submerge by a little more than the height of the tanks and no more. The picture is a total contradiction with respect to the most important design requirements.

It is possible to make a airplane that can submerge and travel under water - it's been done before. However, I don't believe it is likely to have substantial volumes of dry living space. That is buoyancy one just can't afford in such a craft.

I think a flying sub will be a heavy aircraft by its nature, but will also be very light for a sub - it will need to use dynamic lift to stay submerged just like it uses dynamic lift to support itself in the air. And I think it's likely that the living areas will have to be flooded for it to make its underwater dash into the hot zone and back out, then pumped out to allow it to loiter on the surface in more comfort.