Nipponki '46 - "Seiku" Air Defence Fighter.

[Johnbr]

DATA

Engine: two 1700hp liquid-cooled inverted V 12cylinder

Span: 13.2m

Length: 8m

Height: 4m

Main wing area: 23.8sqm

Wing load: 189kg/sqm

Max. speed: 720km/h

Range @ cruising speed: 1,500km

Fuel: 2200l

Crew: 1

Armament: 2 X 30mm, 2 X 12.7mm

"Seiku" (Sky Dominator) is a fast fighter with high climbing speed.

The engines are installed in the same fashion like on the Heinkel 177 and drive a 4-blade propeller via an extension shaft.

Each engine has a turbine exhaust coming out from both sides of the fuselage.

Air intakes are behind both sides of the cockpit with a radiator installed in the middle.


Designed by: Ikeda from Yokohama & Maruyama from Yokosuka

Featured in the November 1944 issue of the magazine "Koku Shonen" (Aviation Youth)

The "aviation expert" of the magazine commented that it is a fantastic design that only needs a little attention in the landing gear and the nose.

Okay, this is one of the most interesting designs in the whole series because it is EXACTLY like the Lippisch P10-108, a 1942 German bomber project that never left the drawing board. From the overall shape and tail-less concept down to the two engines joined side-by-side, the 4-blade props and the extension shaft, the two designs are identical in every respect! Ofcourse it looks a lot like the Me 163 Komet but to me it is really amazing that two amateur Japanese designers thought in exactly the same way and took the aircraft in the same direction the Lippisch designers did.

 

[hesham]

Thank you my dear John,

but are you sure it was real design ?.

 

[blackkite]

重心位置 : center of gravity, 　空気取入口 : air intake, 　プロペラ中心線 : propeller center line, 　排気タービン : exhaust gas turbine, 　発動機 : engine, 　ガソリンタンク : gasoline tank　２５％基準線 : 25% reference line

I can't find radiator and oil cooler.
Perhaps relation between C.G. and air center are not good.(tail heavy)

Yokohama means Yokohama city(Nihon hikoki?) and Yokosuka means Yokosuka city(Kugisho?)
I believe that designers are child, because Hiko Shonen magazine was for child.

 

[Hood]

Completely fictional, but certainly an impressive design. I would not write off the 'designer' of this as a child, probably a young student for sure, possibly studying engineering. I wonder if this was based on reports of the Me 263 as the inspiration or Lippisch's pre-war glider work?

 

[riggerrob]

Good observation on balance.
Unless guns weigh as much as engines, it would be tail-heavy.
Centre of gravity needs to be forward of centre of lift for cruise stability.

Is that a landing -flap or dive-brake under the centre of gravity?

 

[Grzesio]

Centre of gravity needs to be forward of centre of lift for cruise stability.

And a tailless aircraft generally needs to be nose heavy (as compared to conventional layout), as this is compensated by a self stabilizing wing profile or twisted tips of a swept wing (as is the case here). So this interesting design does not look good as far as CoG position is concerned.

 

[blackkite]

Yes I think this design was not a professional work. But interesting and ambitious design, hard to believe Japanese youth work at the day.
Is it better to have contra rotating prop?
I believe Jack Northrop liked such a design.