Intended use for Ju-287 jet bomber ?
 

The Ju-287 was a very odd jet bomber design. It had forward swept wings, with two engines hung beneath the wing and another two along the forward fuselage. It's body was a cut down He-177 Grieff bomber's fuselage, with a Ju-388 tail and assorted fixed undercarriage. The V1 prototype flew 17 test flights from August 1944 to April 1945.

The V2 was fitted with retractable undercarriage, but the factory was captured by the soviets. Subsequently the design was developed further by the Soviets as the IL-28 (Nato codename Beagle).

"Ju-287, The World's First Swept Wing Jet Aircraft," by Horst Lommel, Published by Schiffer, ISBN 9-7643-2059-9, observes that the Ju-287 had a bomb bay identical to the He-177 V38 aircraft. The V38 and two other He-177 aircraft were developed from 1942 in Prague as deratives of the usual He-177.

These three aircraft were intended to carry nuclear weapons. They had an unusual 5 metre long bomb bay, for intended bomb payloads of 4,000kg. The Ju-287 shared this bomb bay.

I came across this fact whilst researching whether the Nazis came close to developing an atomic weapon. I am already satisfied that germany developed the Harteck centrifuge process to enrich uranium, subsequently copied by South Africa and Pakistan after the war. Now being used by Iran. I am aware that Germany had refined at least 1100 tons of uranium (probably from Czechoslovakian mines at Jach-ymore) at the Auer Gesellschaft refinery at Oranienburg north of Berlin. From November 1943 Germany was even exporting uranium by u-boat to Penang for Japan's atomic bomb project.

I am not sure if I am telling the story, or asking the question, but I welcome imput from others. Does anybody know more about the intended mission of the Ju-287 and for that matter why development appeared to be so slow when other projects advanced so fast ?

Also please, I gather conventional German bombers could not penetrate British airspace from 1943 onwards ?

Is that correct ?

Anyone care to comment ?

Re: Intended use for Ju-287 jet bomber ?
 

Conventional bombers could not penetrate British defences without heavy losses. Heavy meaning the kind of losses that make an extended campaign unacceptable. The qualification is important.

The evidence that the larger bombbay was to carry an atomic bomb is specious. On the same level of evidence, perhaps the Lancaster's bombbay was big so it could carry an atomic bomb?

Was the development of the Ju 287 particularly slow? By the standards of other large aircraft in Germany at the time? Given the downright peculiar aerodynamics/structure of a swept-forward wing?

Re: Intended use for Ju-287 jet bomber ?
 

Please correct me if I am wrong, but basically the shape was dictated by two factors. The prototype was a concept a/c and as such used as many ready parts as possible and it was forced to rely on weak engines. Last but not least, reality forced any bomber development to the background.

After writing the above I decided to double check and hence to quote Manfred Griehl (p. 287 of Jet Planes of the Third Reich Vol. 2)

Since no practical experience on the behavior of the novel swept-forward wings existed, Junkers engineer in charge of prototype construction, Dipl. Ing. Ernst Zindel, decided to improvise a flying testbed in order to begin flight trials in the shortest possible period.

If you wish to learn more about the design and its influence on Soviet aircraft development, you should look for Deutsche Spuren in der Sowjetischen Luftfahrtgeschichte, by Dimitri A. Sobolew (I believe it has also been translated to english).

The Atomic bomb side I cannot comment on.

Re: Intended use for Ju-287 jet bomber ?
 

Ruy: your comments apply specifically to the V1. The adaptability or not to any specific weapon would apply to the basic design, rather than the specific compromises of a testbed.

The forward sweep offers theoretical aerodynamic advantages, though I have long forgotten what they might be. However, it does bring with it considerable aero-structural problems. When a wing experiences load, it not only bends but twists. With a swept-back wing, this acts to reduce the aerodynamic forces at the expense of lift, but the forward-swept tip this bending increases the forces. This means that a forward swept wing design requires a heavier structure, which counteracts and indeed exceeds the theoretical benefits of the configuration.

The Soviets seem to have grasped this early on, and their swept-wing designs are aft-swept. Baade was released to work in East Germany on his ideas, resulting in an early but unsuccessful jet airliner. The MBB Hansajet is the only production aircraft to feature fsw, here cleverly using the aft centre-section to improve the capacity of the passenger cabin. However, the design was uncompetitive in the international market - not necessarily because of the fsw.

Recent advances in carbon-fibre structures led to the idea of tailoring layers of fibre within the structure to control the bending and twist, so that the aerodynamic advances could be achieved at no (or lower) weight penalty. Hence the X-29 and the Berkut. The X-29 trials failed to deliver the expected benefit: who knows what the Berkut proved? (Other than that the Russians can make gloriously exciting if pointless devices? Rather like late war Germany?)

Please excuse digression. The Ju 287 was clearly an aircraft well ahead of its time (which is not intended as a compliment), and the designers would have been better employed on something rather more conventional.

Re: Intended use for Ju-287 jet bomber ?
 

One other point. although the Russians did continue to develope the Ju 287 concept and even built one but it was not the IL 28. IIRC it was the Il 22, and apparently wasn't very successfull as they droped development.

The Il 28 was a Russian designed medium bomber that bore no resembelance whatever to the Ju 287. It led a long operational life surviving into the 70s.

Walt

Re: Intended use for Ju-287 jet bomber ?
 

Here is a photo of the modern Su 37 with forward swept wings.

http://www.planespot.com/aviation/su-37.htm


The use of two engines positioned near the front of the aircraft was tested in the US on the XB-51.

That the Germans had developed the atomic bomb is a certainty. A layout diagram was discovered in a Russian archive. It is a fact that the Americans acquired 1100 tons of uranium ore at a location near Stassfurt on April 21, 1945. The source of uranium for the US after the war was the Belgian Congo.

My father, who ended up in the American Zone in Germany, was approached by some men shortly after the war. He was promised a large payment in cash and gold if he agreed to join an operation headed for the Belgian Congo. Not knowing who they were or what might be behind this request, he refused. In the book Critical Mass, author Carter Hydrick uses original documents and access to people who worked in the American atomic weapons program to show that a captured u-boat was carrying enriched uranium in gold lined containers. It also carried infrared fuses. The uranium ended up in the atom bombs dropped on Japan.



Ed

Re: Intended use for Ju-287 jet bomber ?
 

Just replying to one post at a time, Graham you are selectively disregarding information.

Several lancasters in 617 squadron did have bomb bay modifications for dambusting and Grand Slam bombs.

To make the analogy about an ordinary Lancaster that it had a special mission would be folly, but if one were to observe a 617 Sqn Lanc and see an unusual bomb bay one would be quite justified in saying that the departure from normal configuration was for an unusual purpose.

In the case of the He-177 Grieff V38 we are advised the reason for such deviation was to create a bomb bay for a nuclear weapon. When a subsequent aircraft turns up with the same bomb bay and able to overcome the "heavy losses" issue over British airspace at a time when most of the Luftwaffe bomber force was disbanded does suggest an intended special mission over Britain.

This is the process of Ockham's Razor. To apply your thought process to reject everything that is not in official war histories because you don't wish to explore the possibility is not a valid logical thought process.

The purpose of a forum is to explore the facts and uncover history which may for whatever reason may be lost to us in the present day. Just blankly denying and blocking that exploration serves no purpose.

In the absence of some other logical theory we have a series of related unusual facts all pointing to a similar conclusion.

I am inviting anyone to point towards some other logical answer which fits all the known facts. It is also true that the design team for this aircraft were captured and employed during the Cold War by the Soviets. Just like in the West many of these WW2 high tech projects became shrouded in mystery or disinformation.

i am ernestly trying to peel back the facts.

Re: Intended use for Ju-287 jet bomber ?
 

Dear Walt,

I am perfectly familiar with the Il-28 thank you and yes there is not only a resemblance but the missing link is the EF-140R developed by Hans Wocke from the Ju-287.

The IL-22 was a much larger four engined type with very conventional wings and the IL-22 had far less resemblance to the IL-28 than did the Ju-287/EF-140R.

The forward swept wings allowed low speed handling whilst permitting high speed flight. The purpose of the Ju-287 clearly did not anticipate fighter like manouvers so wing twist was perhaps not the developmental barrier suggested.

My research into Farm Hall transcripts (evesdropped conversations by captive Nazi scientists postwar) reveals that Gen. Dornberger was recorded relating how he and von Braun (V-2 rocket) went to Lisbon in October 1944 and discreetly negotiated the surrender of nazi scientists to the Americans through talks with General Electric Corporation.

I wonder if the real reason why progress with the Ju-287 and EF131 was slow might have been due to political rather than technical issues ?

Why for example when in 1945, Mustangs were making low level straffing runs over every airfield in Germany, were the experimental aircraft at Reichlin neither damaged by Allied air attacks nor by the nazis themselves ?

Re: Intended use for Ju-287 jet bomber ?
 

Calling the EF 140 the missing link between the Ju 287 and Il-28 requires some stretching of the imagination (IMHO).

Again, Sobolew does cover this ground pretty well.

IMHO this thread raises a familiar question.

Do we research with on open mind, or do we back track, fitting evidence to our ready conclusion.

As such, if we approach the issue with an open mind, meaning the sum of evidence adds up to a conclusion, we must conclude that we lack the evidence to support the thesis.

The German bomb discussion seems to beach on lack of hard evidence.

Re: Intended use for Ju-287 jet bomber ?
 

Doing my Moderator bit, I don't think that Graham's post merited this kind of response. His points were not unfair or as dismissive, to my eyes, as you seem to have found them.

Speaking as a forum member, I have some problems with your reasoning in the following passage:

First "we are advised" ... by whom and on what authority? Do we in fact know the reason for the enlarged bomb bay; is it documented or is the idea of an He 177 carrying a nuke just speculation? Maybe it was to carry more or bigger conventional bombs or fuel tanks or whatever...

Second, I'd say the bombers force's decline had more to do with fuel shortages and diversion of industrial capacity to fighter production than loss rates. By 1944, the Luftwaffe couldn't operate its fighters or ground attack units without terrible loss rates either but they kept going.

Third, is it safe to assume that Britain was the target of choice, rather than the Soviet hydro-electric plants, for example?

Fourth, despite what Ed West wrote, what German A-bomb? I'm not a believer on this one. They hadn't even achieved a sustained chain reaction in the Kummersdorf pile, had they? America had the vast industrial capacity to develop the bomb (including uranium enrichment), did Germany? If so, where was the research and production programme on the scale required? Where were the weapons components - the casings even? Did they in fact have a good enough idea of the weight and configuration of an operational fission weapon to start redesigning an aircraft around it?

Fifth, I don't have range/payload figures for the He 177 or Ju 287 to hand but just because they shared a fuselage, doesn't mean they were equally suited to given operational profiles.

Plus, there's a whole "what if?" argument to be had about how vulnerable an operational Ju 287 might or might not have been against centimetric radars, Allied jet fighters, proximity-fused AA shells and intruders stalking its bases.

What you call Ockham's Razor looks to me more like a leap of faith. What you assert is not impossible but personally that's as far as I'd go with the idea.