Stupid Weapons of the Luftwaffe: The Ju-287

The F-4D was influenced by the work of the Lippisch Brothers.

It's Zombie season..........and Zombies don't die..............

And "The Walking Dead" restarts next week - how convenient! 

plasticjunkie

Just realized this thread is from 2011 and is still alive. 

 

It's Zombie season..........and Zombies don't die..............

[quote user="BigJim"]

Bringback the Flap-Jack

[quote]

LOL !

I enjoyed building that kit.

Kit was even better when I was able to watch the wings flap.

Shame the motor wore out.

All, one of the biggest issues with swept forward wings is that they twist in such a way as to increase the manuever.  Start a roll and unless the wing is stiff enough, you get the wing helping out.  The larger the control surface delflection, the greater the twist.  Could take the wing right off if it got out of hand.  That is one reason the Hansa jet had such a heavy structure.  Swept forward wings do stall nicer than conventual wings, maintaining roll control well into the stall range since the tips stall last.  As I recall, the X-29 FSW concept plane didn't offer enough advantages relative to an F-16 at high AOA manuevering to justify building one in production. 

John

But it did! The unusual layout was in part to offset engine torque, which it seems worked out well for the earlier BV-141A-0 series with the smaller (BMW Bramo?) engine.  The story goes that the RLM deemed the A series underpowered, so Blohm und Voss replaced the Bramo with a BMW 801 series engine (like the Fw-190 used), but the plane suffered vibration problems and combined with a new offset tailane, the delicate balance in the A series was lost.

TomZ2

Good build and a 1st rate weirdie. But to my mind, the champion is the Blohm & Voss 141: http://www.youtube.com/watch?v=oxV1FkD-oL4&feature=player_embedded or:

 

There's no way that thing could possibly fly. LOL!

Just realized this thread is from 2011 and is still alive. 

Bringback the Flap-Jack

I think Allen109's comment on aeroelastic instability going up as speed increases is the main obstacle to a production aircraft entering service. The only FSW aircraft so far that has gone beyond the prototype stage is the Hansajet. But I believe the FSW configuration was selected to keep the spar behind the cabin, and the sweep angle was modest. Plus no dogfighting allowed with a bizjet!

I remember reading a long while back that the FSW became highly unstable the closer it got to Mach,and would disintigrate at, or above, Mach.

I also remember a guy I know with close ties to the USAF tell me that the F-16 pilots have been instructed to punch out if one of the two stability control computers goes out.

If I am wrong-please correct me.

Bish

And it should not be forgotten that some of these designs were tried again after the war. Some did not make it to production.

 

But others certainly did.

 

Just look at the Ho229 influence on this B-2!

And it should not be forgotten that some of these designs were tried again after the war. Some did not make it to production.

But others certainly did.

You never know if it will work until you try it.

Bish

 The Germans certainly had some strange designs. .

 

I think Bish hit on the proper title, "Strange Designs of the Luftwaffe". Strange and weird indeed and then there is the futuristic Horten design. Great job on an unusual subject.

Really nice looking build !

Must be gigantic next to the Triebflugel........

Dunno how I missed this thread the first time around.

Real G

Bsyamato - You smell a GB feeler?  Yeah, I'm a trouble maker at heart, but I shouldn't be starting another project right now.  Maybe later.

As you know i am busy too, keep it in mind for the gb idea, i have a reaaly weak memory

Real G

TomZ2 - Huh, I never knew that the F-117 was unflyable without a computer.  I didn't think it would have sparkling handling, with those sharp faceted edges and all.  I always thought that the "wobbly goblin" nickname was something the press grabbed on to, to criticize the F-117.  Regards to earlier fighter designs, you are absolutely right in pointing out marginal stability being a desirable characteristic.  Thanks for setting the record straight!

Teeny, tiny point: it’s “wobblin’ goblin” [the AF may have even trademarked it], not “wobbly goblin”. Watch this video. About mid-way through, you’ll see a fine display of “wobblin’” action.

http://www.youtube.com/watch?v=3g-QSZjbtWg&feature=related

TomZ2 - Huh, I never knew that the F-117 was unflyable without a computer.  I didn't think it would have sparkling handling, with those sharp faceted edges and all.  I always thought that the "wobbly goblin" nickname was something the press grabbed on to, to criticize the F-117.  Regards to earlier fighter designs, you are absolutely right in pointing out marginal stability being a desirable characteristic.  Thanks for setting the record straight!

Bsyamato - You smell a GB feeler?  Yeah, I'm a trouble maker at heart, but I shouldn't be starting another project right now.  Maybe later.

Real G

I think the fundamental problem with FSW is that it is always unstable.  With other aircraft like the F-16, you can dial in negative stability by shifting the C.G. back using fuel.  If the flight computer craps out, it would be possible to manually adjust the C.G. back to a forward location, thus making the aircraft controllable.  (I think - isn't that the way it works?)  That is not possible with FSW, so a computer malfunction would render the aircraft unflyable.

Actually, for WWII and later fighters, it frequently isn’t (the way it works, I mean). Aircraft like the Zero were only marginally stable. (Let go of the stick and bye-bye!) The engineers weren’t stupid. They didn’t WANT their fighters to be fully stable; they wanted them maneuverable and that means aerodynamically unstable (at least that’s how I was taught to built ‘em). For the worst case, the F-117, if the on-board computers are disabled, even the best pilot cannot control it — they’ve GOT to punch out, but that’s more a side-effect of its faceted geometry than the designers wanting to make it unusually maneuverable.

Ye, i think it would have worked, and hadn't they proved the concept with gliders. Interesting that you say the bomber version would have been to unstable. I don't know alot about the B-2, but would i be right in assuming that thats largely helped by the use of computers, and with them that to would be to unstable.

As for the FSW and the computer malfunction, well the same is true of the Eurofighter. Without it's computers, it would fall out of the sky. But its interesting to note that the US actually wnet as far as building an FSW to fin d out about it.

Bish,

I think the Ho-229 flying wing fighter might have actually worked, without the endorsement of that stupid NatGeo show on the aircraft.  The bomber vesion not so much, as they would have had the same stability problems of the Northrop XB-35/YB-49 flying wings.  Unstable fighter - yes.  Unstable bomber - no.  The Triebflugel might have functioned but not worked well.  Again, real world experience with the Convair "Pogo" showed that landing was a real bugger with tail sitter aircraft.  Imagine trying to touch down in the Black Forest with dozens of hungry jabos swarming around you like flies at a picnic.  The P.13 was a no-go from the get-go, as its airfoil was too blunt for supersonic performance.  Its propulsion system was also highly suspect, as it was supposed to be a ramjet fueled by coal!

I think the fundamental problem with FSW is that it is always unstable.  With other aircraft like the F-16, you can dial in negative stability by shifting the C.G. back using fuel.  If the flight computer craps out, it would be possible to manually adjust the C.G. back to a forward location, thus making the aircraft controllable.  (I think - isn't that the way it works?)  That is not possible with FSW, so a computer malfunction would render the aircraft unflyable.

But damn, it sure looks cool!

1. I’d claim that no one knows what any aircraft ‘should’ look like. Form follows function. Even engineers only have prejudices (extremely expensive and well educated prejudices) as to how their work ‘should’ look; the laws of physics (and economics) get the final say.
2. Blohm & Voss was (and is) a shipbuilding concern. [See below.] Their attempts at building aircraft were decidedly weird, visually, nonetheless as they say, ‘if it’s stupid, but it works, it ain’t stupid.’
   
3. There is no #3. It was stealthed. Shhh!

Wikipedia

From 1933 to 1945, Blohm & Voss also operated the Hamburger Flugzeugbau aircraft company. Although initially given the factory code Ha (for the factory’s official name), the link with Blohm & Voss shipyards proved too strong and therefore the early aircraft designs were called “Blohm & Voss, type Ha…” followed by the design number. To end this confusion, in 1938 the Reichsluftfahrtministerium gave in to the unavoidable and changed the company code to BV.

And who knows how many of them may have actually worked. After all, the flying wing would have looked, and still des look, like an odd concept.

What ever happened to the idea of the FSW. Did the US decide it was a no go.

Real G

Thanks guys for the comments!  I'm glad you enjoyed the pics.  I hope I have infected  inspired some of you ..

that's smells like teen spirits a sort of weid flying things gb feeler .... sniff

VanceCrozier,

Hey, they didn't know what should look right back then!  The Germans were desperately pushing the boundaries of theoretical aeronautics at the end of WW II, and there was really nothing out at the time to tell them if they were headed in the right direction.  But the old adage "if it looks right, it will fly right" was true back then as it is today.  Poor, poor Richard Vogt, designer of the BV-141.  He's one of my aircraft designer heros.

BTW, has there ever been a GB for freaks, flops, and failures?  (I got a closet full of them!)

Bish

...The Germans certainly had some strange designs....

They certainly didn't feel restrained by "what an airplane should look like" did they?

Now those are very nice. The Germans certainly had some strange designs. And there are some nice kits out there, especially if you don't mind pricey resin. Would be nice if Revell would bring out some more Luft 46 kits, as they have a few nice ones.

Nice to seen another fan of the what if's, i'll never get tired of seeing them, especially when they are of that quality.

Waikong,

Yes, the FSW concept is possible today thanks to the advent of digital flight controls and active damping.  Back in the analog days of WW II, the designers had to rely on the instincts and reflexes of the test pilot.  Them were wild and wooly days!  It is interesting to note that to date, the Germans are the only ones to have pulled off a production FSW aircraft, the Hansajet.  I'd like a nice 1/72 kit of that one!