German forward swept wing WWII fighter projects.

[Charles Gray]

Here's a question-- the Germans had several forward swept wing designs
in the works during WWII.
However, I recall reading that even in the 1980's the strain on the
airframe made such a design very difficult to successfully carry off.
That being the case, was there any realistic chance that such fighter
designs could have been successfully fielded, or is this a case of a
severe underestimation of the problems by the engineers?

[robert arndt]

Charles Gray > wrote in message >...
> Here's a question-- the Germans had several forward swept wing designs
> in the works during WWII.
> However, I recall reading that even in the 1980's the strain on the
> airframe made such a design very difficult to successfully carry off.
> That being the case, was there any realistic chance that such fighter
> designs could have been successfully fielded, or is this a case of a
> severe underestimation of the problems by the engineers?

A partial list of the projects:

He p.1076
Bv p.209/II
Ju EF 122
Ju EF 125
Bv P.188.01 (variable incidence wing)

Of course there were swept-forward proposals for the Ar 234, He 162,
Me-262, and the Misteln too. The only real aircraft with forward sweep
that the Germans got into the air was the Ju-287 jet bomber which flew
well enough for the Soviets to copy it in the USSR.
Postwar, West Germany had the MBB HFB 320 Hansa jet that worked well
too, the US toyed with the X-29, and today the Russians have the Su-47
Berkut (aka Firkin).

Rob

[robert arndt]

Charles Gray > wrote in message >...
> Here's a question-- the Germans had several forward swept wing designs
> in the works during WWII.
> However, I recall reading that even in the 1980's the strain on the
> airframe made such a design very difficult to successfully carry off.
> That being the case, was there any realistic chance that such fighter
> designs could have been successfully fielded, or is this a case of a
> severe underestimation of the problems by the engineers?

Some pics:

Ju-287: http://www.luftwaffepics.com/LCBW/Ju287-7.jpg
Ju EF 131: http://tanks45.tripod.com/Jets45/Histories/Ju-287/Ju-287V3.jpg
Ju EF 140: http://tanks45.tripod.com/Jets45/Histories/Ju-287/Ef-140R_1.jpg
MBB Hansa: http://www.flygplan.info/images/Hansa%20HFB%20320%20ECM.jpg

Enjoy,
Rob

[Andreas Parsch]

Charles Gray wrote:

> Here's a question-- the Germans had several forward swept wing designs
> in the works during WWII.
> However, I recall reading that even in the 1980's the strain on the
> airframe made such a design very difficult to successfully carry off.
> That being the case, was there any realistic chance that such fighter
> designs could have been successfully fielded, or is this a case of a
> severe underestimation of the problems by the engineers?

The latter, essentially. The Germans weren't really aware of the aerodynamic
wing twisting problems of FSW in high speed aircraft. In fact, the Ju 287
prototypes were limited to relatively low speeds (< 400 mph) for exactly
this reason. While the engineers tried to make the wings more stiff, this
would have only pushed the limit slightly up but wouldn't have solved the
problem. A high-speed FSW can't be made without modern composite materials.

Andreas

[Andreas Parsch]

robert arndt wrote:
>
> A partial list of the projects:
>
> He p.1076
> Bv p.209/II
> Ju EF 122
> Ju EF 125
> Bv P.188.01 (variable incidence wing)

"Paper" projects only.

>
> Of course there were swept-forward proposals for the Ar 234, He 162,
> Me-262, and the Misteln too. The only real aircraft with forward sweep
> that the Germans got into the air was the Ju-287 jet bomber which flew
> well enough for the Soviets to copy it in the USSR.

Probably only to find out what we know today: That the wing-twisting problem
couldn't be solved with 1940s materials and technology. After all, the
Soviets didn't field any operational FSW aircraft so far.

> Postwar, West Germany had the MBB HFB 320 Hansa jet that worked well
> too,

Only very slightly forward-swept (for completely other reasons than
high-speed flight), and max speed was well below the problematic regime.

> the US toyed with the X-29, and today the Russians have the Su-47
> Berkut (aka Firkin).

Both using modern composite wings and flight-control systems. _Today_ you
can build high-speed FSWs, but not in 1945.

Andreas