Equator aircraft

An interesting site :


EQUATOR AIRCRAFT

Hi!

Looks like company changed both their location and design team:
http://www.equatoraircraft.com/


Now in Norway and working on the quite elegant flying boat Equator P2 Excursion

Former company was Pöschel Equator, this jet amphibian seems to
be derived from the P-300:
http://www.seabee.info/seaplanes/seaplanes_germany.htm

Hi,

here is the drawings.

I don't understand how this aircraft remains stable laterally in rough waters (second drawing) without any underwing floats. Ideas, anyone?

The design principle is pretty much the same as the Beriev 102. Unfortunately, that design was terrible in anything but calm water.

Dave

It's like with the old Dornier flying boats, where sponsons protruding from the lower fuselage provided stability. In this design, the Dornier sponsons are lengtened into true wings. The downside is, in rough water a wing's lower surfaces are likely to touch the waves -> asymmetric drag does horrible things to your take-off / or both wings touch the waves -> lots of drag and no take-off at all.

Arjen said:

It's like with the old Dornier flying boats, where sponsons protruding from the lower fuselage provided stability. In this design, the Dornier sponsons are lengtened into true wings. The downside is, in rough water a wing's lower surfaces are likely to touch the waves -> asymmetric drag does horrible things to your take-off / or both wings touch the waves -> lots of drag and no take-off at all.

Click to expand...

Well, I know the Dornier designs of course, and the sponsons are large enough to do the job.
But in the Equator they are so narrow that I can't fathom their efficiency in balancing the aircraft, especially with the weight of the jet engines on top.

Skyblazer said:

But in the Equator they are so narrow that I can't fathom their efficiency in balancing the aircraft, especially with the weight of the jet engines on top.

Click to expand...

I think enough stability is provided, even more than in the Dorniers. The more the aircraft heels over, the bigger the part of the wing that's submerged, providing more buoyancy. Not that much is needed anyway. Have a look at the Seabee, which has its engine up high too. The wingtip floats are tiny.

Image from wiki.

Be-103 from wiki:

Thanks, but I'm not convinced by these examples. The way I see it:

The Equator has very sharp dihedral and no sponsons. It means it can swing easily to the left or the right of its thrust line. I've estimated the angle between the wing and the sea to be approximately 6 degrees. When the sea gets rough, the wing can go flat, resulting in the other wing going way up. And because there are no floats at the wing tips, there is potentially nothing to prevent the wing from being submerged. Also, once the aircraft is way off balance, the engines, which are relatively central, add to the swinging.

The Seabee had floats, however small. Not only the discrepancy between the floatation line of the fuselage and that of the floats is minor (I've estimated it at 3 degrees), but the very presence of the float, however small, keeps the wing from moving any further down in case of lateral swing.

The Be-103 has a near gull-wing design. The part that is closer to the fuselage on either side is flat and acts in the same way as the Dornier sponsons. It keeps the aircraft upright in a rough sea. Because of the cranked wing, even if the wingtip came close to the water, the flat part would maintain the aircraft afloat anyway. The wing could not be submerged. The engines being well apart on either side of the fuselage, there wouldn't be such a massive weight to offset the aircraft's balance when it swings to one side, as the engine on the other side would act as a counterweight.

As I said, this is my understanding of it, but I'm no engineer and I'm open to comments and criticism, and willing to be proven wrong if I am!

With an entire wing submerged, that's a lot of buoyancy exerting an upward force on that side - if it will ever heel over that much.

They will heel that much. I have personally seen Seabee (and similar aircraft) totally submerge the tip floats. I have never seen a picture of any Equator aircraft doing serious work on the water. I remember some 30 years ago their press releases mentioned that the amphibious capability would come in future prototypes. Can you say "vapourware"?

The other issue is how a wing strike will work during landing (e.g. will it skip off the water like a float or will it dig in?).

The Be-103 partly escapes this because of the low landing speeds when acting an Ekranoplan ...but it still makes me a bit uncomfortable in any environment where the surface isn't like glass and the wind isn't calm

It's fair-weather friendly?

Maybe it's interesting to get to know, what became of prototypes are ?
Yesterday on the area of the Flughafenmuseum Cottbus (Airport Museum Cottbus), I saw quite a
strange aircraft tail, that emerged as the derelict fuselage of the Pöschel P-300 Equator prototype.
It was the only prototype with this layout and made its maiden flight in 1971. After problems with the
transmission and the propeller, which was positioned in the tail fin, it was abandoned in 1975.

They are now close to first flight. Then the thread should be moved to aerospace.

Reaper said:

They are now close to first flight. Then the thread should be moved to aerospace.

Click to expand...

It's still just a prototype then and you see, what this can mean in the end.
From the "Posting Topic Guidelines", point 4: " ... Prototypes that didn't enter series production may also be appropriate."