Secret Projects of the Luftwaffe: Heinkel He 162 by Dan Sharp

[newsdeskdan]

Just sent this book to press today. Physical copies should be available from Monday, November 16.

Secret Projects of the Luftwaffe: Heinkel He 162
by Dan Sharp

It's 172 pages with around 130 images - including many previously unseen drawings plus profile artworks by secretprojects.co.uk forum member Zizi6785 - for £12.99.

Heinkel’s single-jet He 162 fighter arrived in Luftwaffe service at the very end of the Second World War - but its development can be traced back to the beginning of July 1944. A contest had been set in motion to design a powerful and aerodynamically advanced replacement for Messerschmitt’s twin-jet Me 262 and Heinkel believed it could win.
As the competition progressed and Germany’s resources dwindled, it became clear that an advanced jet fighter was not what the Luftwaffe needed. A new concept was formulated: a cheap, basic fighter equipped with a single readily-available turbojet. The advanced fighter contest was temporarily shelved and Volksjäger was born.
Swept metal wings, V-tail and HeS 011 engine swapped for straight wooden wings, conventional tail and BMW 003 engine, Heinkel’s fighter design was rushed through a brief selection process before Adolf Hitler himself placed an order for 1,000 a month. A massive effort saw the He 162 go from blueprints to flying prototype in less than two months. But was it a triumph of engineering prowess or a costly white elephant which hastened the end of the war? Using contemporary documents, author Dan Sharp explains and explores the development history of this fascinating and controversial late-war ‘secret project’.

In short, this is not a complete history of the everything to do with the He 162. It only barely touches on the production side and efforts to get the type into Luftwaffe service. Rather, it looks in great detail at the design and development of the He 162 as a 'secret project' and uses primary sources to find answers for questions such as what exactly caused the He 162 V1 to crash; which prototypes had the lengthened fuselage and exactly how long was the extension; was there ever an He 162 B, C, D or E and if so what were they; is 'Salamander' a legitimate name for the type; when exactly did Alexander Lippisch become involved with the project and what did his contribution consist of; was Goering 'tricked' into approving the He 162 development using faked cinema footage of one flying; how do the famous 'Russian' drawings of the P 1073 match up against contemporary German ones; exactly whose idea was it to make the He 162 a Hitler Youth project and how was that supposed to work; what was the difference between the BMW 003 A-1, E-1 and E-2 and was the E-2 ever installed in an He 162; what exactly was the cause of the He 162's infamous lateral instability; which trainer variants of the He 162 were built, what were they called, and what future developments of the type were actually approved for series production and more.
You may think you know the answers to all those questions - I thought I did - but what the primary sources (all listed, along with their locations should you wish to track them down and examine them yourself) have to say may surprise you.

 

[newsdeskdan]

Now back from the printers...

 

[Sundog]

I'm definitely getting one.

 

[GTX]

Order placed.

 

[elmayerle]

My order has been pre-placed for some time. Looking forward to getting this one.

 

[sgeorges4]

uh I can't find this one on ebay ,is it normal?

 

[elmayerle]

My copy arrived today and it looks very interesting, indeed. I've not yet been able to delve much into it, but there looks to be plenty of "meat" there.

 

[Zizi6785]

My favorite new discovery is in the form of a color profile:

 

[richard B]

My favorite new discovery is in the form of a color profile:
View attachment 646425

What is it ? It looks something like a twin booms Arado E.580

 

[Zizi6785]

My favorite new discovery is in the form of a color profile:
View attachment 646425

What is it ? It looks something like a twin booms Arado E.580

Exactly

 

[Madoc]

An excellent book!

I'm quite happy with my purchase of one. I'd always thought the He-162 was this "fly by night" thing thrown together in a rush and only at the behest of the SS in order to get Hitler Jugend kids to pilot them. That's what the plane was depicted as in almost all the write-ups of it I encountered. Little mention, if any, was given to the relatively long history of development of the plane. They all made it seem as if the design was solely created for the Emergency Fighter program and that nothing similar existed before that competition. Instead, the He-162 was a thing of long effort prior to the competition and it was only brought forth and refined into an actual flying machine because of that competition.

And the role of the SS and the child pilots was barely a thing of relevance and one which was only attached to the effort after the Emergency Fighter program was well underway.

It was fascinating to read the history of the program and all its various turns and twists. So many of those that it makes it all the more amazing that even a single He-162 took flight at all. Let alone being deployed to operational squadrons before the war's end.

This was quite an excellent read and a job well done by Dan Sharp.

 

[elmayerle]

I just had time to finish reading this book and I can say it's an excellent and informative read. Lots of new information and a placing of a lot of existing information into proper context and showing the error of several preconceived notions. I have to echo Madoc, "A job well done by Dan Sharp."

 

[HoHun]

Hi Dan,

You may think you know the answers to all those questions - I thought I did - but what the primary sources (all listed, along with their locations should you wish to track them down and examine them yourself) have to say may surprise you.

To shorten the wait for your new Me 262 book, I ordered a copy of your He 162 book (and the BV 155 book as well), and so far, it's been quite a fascinating read. (I'll admit that I didn't even know all the questions you mentioned, much less the answers

Thanks a lot for also including some of the original German pages, as there's always a bit of ambiguity involved in translations, and the no doubt carefully selected ones you provided are in fact very interesting too.

As I believe you're the kind of accurate writer who's going to enjoy this near-hair-splitting stuff, let me point out that I've noticed a really unsual term in the telegram on p. 42, which you translated as "drop tanks", when in my opinion, it actually would have to be "conformal tanks":

- "eventuelle mitnahme von flugzeugebundenen formauszenbehaeltern"

"Flugzeuggebunden" literally means "fixed to the aircraft", and "Formaußenbhälter" means "shaped external tank". (That's not a term I've ever come across anywhere else, personally.)

I would say that would suggest conformal tanks of sorts, which despite the association of this term with modern fighter jets, could really have been something as simple as the "Long Range"Spitfire Mk II's fixed underwing tank, or the Me 110's "Dackelbauch".

Another interesting term that shows up in the Heinkel P. 1073 description on p. 47 is "abwickelbar", and I think you weren't quite sure about the exact translation even though you skillfully managed to capture the gist of it It's in fact a technical adjective used to describe "developable surfaces", as in https://en.wikipedia.org/wiki/Developable_surface , which due to the avoidance of compound curves do indeed simplify construction. This applies to both the wing and the tail cone construction, according to the original.

Great little book, I'm really enjoying it! So far, the only place I had read that the idea behind the He 162 had in fact been the concept of a low-altitude interceptor had been Eric Brown's "Wings of the Luftwaffe", and now your book confirms this and provides a lot more detail on the background, too

Regards,

Henning (HoHun)

 

[newsdeskdan]

Thanks for the notes, Henning.
These three books, Secret Projects of the Luftwaffe: Heinkel He 162, Secret Projects of the Luftwaffe: Blohm & Voss BV 155 and Messerschmitt Me 262 Development & Politics, are really all telling the same story from different points of view. All three aircraft were developed concurrently and for different roles - the Me 262 was the central focus of jet fighter development, with the He 162 being better able to handle low-altitude work and the BV 155 able to reach altitudes way beyond the point at which the 004 would begin to lose power.
The He 162's development was unusual in that it necessitated the use of odds and ends that weren't already being used for the Me 262 and the BV 155's development, though comparatively lengthy, was at a greatly reduced priority and on a much smaller scale. The Me 262, on the other hand, was an enormous top priority project.
If you liked the first two books, which are about 30,000w each, you will hopefully also enjoy the Me 262 book - which is 160,000w.

 

[HoHun]

Hi Dan,

The He 162's development was unusual in that it necessitated the use of odds and ends that weren't already being used for the Me 262 and the BV 155's development, though comparatively lengthy, was at a greatly reduced priority and on a much smaller scale. The Me 262, on the other hand, was an enormous top priority project.
If you liked the first two books, which are about 30,000w each, you will hopefully also enjoy the Me 262 book - which is 160,000w.

I have already ordered your Me 262 book, too Interesting to see the word counts ... even with the "little" He 162 book I'm currently reading, the "information density" is really high, which is the telltale sign of a good book in my opinion - and I guess due to your effort to make your extensive research fit into a single book at all, the Me 262 book is probably going to be just as good in that regard!

Regards,

Henning (HoHun)

 

[gatoraptor]

Hi Dan,

The He 162's development was unusual in that it necessitated the use of odds and ends that weren't already being used for the Me 262 and the BV 155's development, though comparatively lengthy, was at a greatly reduced priority and on a much smaller scale. The Me 262, on the other hand, was an enormous top priority project.
If you liked the first two books, which are about 30,000w each, you will hopefully also enjoy the Me 262 book - which is 160,000w.

I have already ordered your Me 262 book, too Interesting to see the word counts ... even with the "little" He 162 book I'm currently reading, the "information density" is really high, which is the telltale sign of a good book in my opinion - and I guess due to your effort to make your extensive research fit into a single book at all, the Me 262 book is probably going to be just as good in that regard!

Regards,

Henning (HoHun)

Dan's books always rank high when it comes to "information density"!

 

[HoHun]

Hi again,

- "eventuelle mitnahme von flugzeugebundenen formauszenbehaeltern"

"Flugzeuggebunden" literally means "fixed to the aircraft", and "Formaußenbhälter" means "shaped external tank". (That's not a term I've ever come across anywhere else, personally.)

I would say that would suggest conformal tanks of sorts, which despite the association of this term with modern fighter jets, could really have been something as simple as the "Long Range"Spitfire Mk II's fixed underwing tank, or the Me 110's "Dackelbauch".

I just noticed that Messerschmitt suggested similar tanks for a Me 262 project, using the term "zellenfeste Außenbehälter" = "exterior tanks fixed to the airframe":

https://www.secretprojects.co.uk/threads/me-262-projects-pre-projects-and-variants.6994/page-8#post-533789

This term doesn't imply attention to shape like the Heinkel term, though.

Regards,

Henning (HoHun)

 

[HoHun]

Hi,

Secret Projects of the Luftwaffe: Heinkel He 162
by Dan Sharp

It's 172 pages with around 130 images - including many previously unseen drawings plus profile artworks by secretprojects.co.uk forum member Zizi6785 - for £12.99.

I've now finished reading this book - excellent, fully recommended!

Still, there's one point I'd like to disagree with Dan, and it's in his critical appraisal of Willy Messerschmitt's rejection of the Volksjäger plan, which Dan thinks is motivated by Messerschmitt's obvious interests in the continued production of the Me 262.

While I'm perfectly fine with acknowledging these interests, I think Messerschmitt's rejection is actually based on a better assessment of the strategic and tactial reality of the air war over Germany in 1944 and '45 (and where it might have gone in '46, had it come to that).

Here's a summary of Messerschmitt points, which I based on the reproduction of his letter in Luftfahrt International #24 (Nov/Dec 1977):

• The basic idea of introducing a single-engined jet in 1945 is flawed. It will be possible to provide the same number twin-engined jet fighters by simply ramping up Me 262 production by employing the ressources allocated to design, development and production of the single-engined jet fighter to the existing twin. The idea of completing the Volksjäger programme until spring 1945 is unrealistic.
• The Me 262 has proven to be greatly superior to the Allied fighters, but it would be a fallacy to assume the Allies won't improve their designs. It is clear that aircraft superior to the Me 262 can be built, to the Allies as well as to the Germans. Accordingly, Germany should build such a fighter of improved performance, instead of scheduling a fighter of inferior performance (like the He 162) for production.
• Generally, it is correct that the Luftwaffe needs a great number of jets. However, it won't be possible to provide a larger number of jets of a new design until spring or summer 1945 than the number that can be provided by ramping up production of the existing design. This is owed to the well-established industrial learning curve, on which the Me 262 has progressed quite a way, with about 700 examples produced by the time He 162 will start. The He 162 is an untested aircraft, and production initially will be difficult as all kinds of changes have to be introduced into series production to fix the inevitable teething troubles. According to experience, a new design requires about 7 times as much labour as the same type in normal mass production. Hasty development will increase this ratio even further. Just setting up production of a new type is a massive undertaking as well, and this will, unlike production itself, require the employment of a high proportion of valuable skilled labour - 2.5 million skilled labour hours. This will never pay off during the production life of the He 162.
• Tactically, the He 162 will not be able to bring its hypothetically superior numbers to bear since it has 50 % of the engines, but only 33 % of the fuel capacity. This will make the concentration of forces over the enemy's ingress point impossible. Additionally, the fuel economy of such a small design is poor because during taxying, take-off, climb, march to the interception point, return to the base, landing etc. so much of the fuel will be consumed that due to the small tank, only very few actual combat minutes are available. Per combat minute, the fuel consumption will be higher than that of larger types with correct design parameters.
• Operationally, the Luftwaffe is continuously demanding range increases. The Me 262, selected over the He 280 partially because of it offered larger fuel capacity, has received tankage increases since then, and work on external tanks is going on to increase range even further.
• In the six months scheduled for the Volksjäger programme, not only the type has to be developed and introduced into series production, but pilots and ground crews have to be trained, depots have to be set up for the type, supply has to be organized etc. - "I can't imagine a miracle of this sort".
• To invest so much effort in an aircraft with such a dubious timeline, at a time when the Me 262 and the Ar 234 are available as truly superior fighters, has to be seen as a sure sign of panic. The "additional" capacity assigned to the He 162 programme should rather be invested to fully exploit the superiority of the already developed types by producing them in the largest possible numbers for service in spring 1945. There is no reason to play this as an all-or-nothing gamble. The British, when on the defence in 1941, built on the Spitfire with great success, the Luftwaffe has an even better basis for development now.
• To come up with a truly superior design, which might well be a single-engined jet, it would be urgently necessary to allocate resources to begin immediate development for a fighter that would have to enter service in early 1946.

I would say that with the benefit of hindsight, Messerschmitt's assessment can actually be considered fairly accurate, with the only minor point in favour of the He 162 being that it did indeed managed to start mass production in spring 1945, though only very few examples had come off the production lines yet, and ramping up the production was scheduled to take a few months more.

So I'd say that in spite of the plausible suspicion of Messerschmitt being biased against the He 162, this did not mean that he painted the production plans in an unrealistically negative way.

Ganter of Heinkel responded to Ernst Heinkel, Francke and Frydag with a - to me - not entirely convincing letter based on the performance projections for the He 162 with 950 L internal fuel capacity compared to the Me 262 with 1970 L fuel capacity. The He 162 couldn't actually use all of that tankage initially, while the Me 262 had an additional 600 L tank, so the comparison correctly would have been more like 850 L @ 2805 kg take-off weight for the He 162 vs. 2570 L @ 6950 kg take-off weight for the Me 262A-1.

(I seem to remember that Kurt Tank opposed the Volksjäger idea as well, but it seems his letter was published in some other issue of Luftfahrt International which I can't find at the moment though I'm pretty sure I must have read it in that magazine.)

Regards,

Henning (HoHun)

 

[newsdeskdan]

Hi,

Secret Projects of the Luftwaffe: Heinkel He 162
by Dan Sharp

It's 172 pages with around 130 images - including many previously unseen drawings plus profile artworks by secretprojects.co.uk forum member Zizi6785 - for £12.99.

So I'd say that in spite of the plausible suspicion of Messerschmitt being biased against the He 162, this did not mean that he painted the production plans in an unrealistically negative way.
Ganter of Heinkel responded to Ernst Heinkel, Francke and Frydag with a - to me - not entirely convincing letter based on the performance projections for the He 162 with 950 L internal fuel capacity compared to the Me 262 with 1970 L fuel capacity. The He 162 couldn't actually use all of that tankage initially, while the Me 262 had an additional 600 L tank, so the comparison correctly would have been more like 850 L @ 2805 kg take-off weight for the He 162 vs. 2570 L @ 6950 kg take-off weight for the Me 262A-1.
(I seem to remember that Kurt Tank opposed the Volksjäger idea as well, but it seems his letter was published in some other issue of Luftfahrt International which I can't find at the moment though I'm pretty sure I must have read it in that magazine.)

Regards,

Henning (HoHun)

Having previously included the full transcript of Messerschmitt's objections to Volksjaeger, which he submitted in October 1944, in my ebook The Hated Volksjaeger, I decided not to include them again in this book. The English version below is from the National Archives at Kew, but the German originals (or contemporary copies thereof) can be found at the Imperial War Museum, the BA-MA and NARA - probably other places too.
I have that copy of Luftfahrt International somewhere but it's been some considerable time since I last opened it. Given that Messerschmitt's views are well known and covered by practically every other book on the He 162 (including my own earlier ebook) I felt it was enough to provide, in Appendix IV, Seiler and Messerschmitt's 'interrogation' of Frydag from April 11, 1945, which is at least a slightly different perspective.
With reference to the page below, I remain reasonably confident that Willy Messerschmitt's rejection of the Volksjäger plan was motivated primarily by his obvious interests in the continued production of the Me 262. Certainly, he does raise plenty of valid concerns regarding performance etc. but I believe the main thrust of his argument relates to production. He simply wants all resources, if any are available, put into the Me 262. Everything else is a supporting argument towards that key point.
After the war, it became very fashionable to criticise the He 162, so I would not be surprised to see Kurt Tank joining in (though I don't recall seeing any wartime objections to it from him).
But the war was lost long before the genesis of the He 162 and I'm not sure it would have made any real difference to how things played out if the He 162 had never existed. This renders arguments against the 162 rather irrelevant and hence not worth the space in the present book.

 

[HoHun]

Hi Dan,

Having previously included the full transcript of Messerschmitt's objections to Volksjaeger, which he submitted in October 1944, in my ebook The Hated Volksjaeger, I decided not to include them again in this book.

Oh, that's your book too? I actually bought and read that a couple of years ago, guess I'll have to check it out again now!

After the war, it became very fashionable to criticise the He 162, so I would not be surprised to see Kurt Tank joining in (though I don't recall seeing any wartime objections to it from him).

From my fallible memory, it was his initial response to the Volksjäger project, though unlike Messerschmitt, he didn't refrain from contributing a design in the end. If you haven't seen that letter yet, I'll have to dive into Luftfahrt International again to see if I can find it. As it's not in the three "Volksjäger" issues, I figure it might have been published be in a "Flitzer" context.

I'd also agree that the He 162 has been unjustly criticized, as it turned out to be a very successful implementation with only minor teething troubles, and the few shortcomings it had were mainly due to the BMW 003 not quite being up to the level of the Jumo 004 in some aspects.

This renders arguments against the 162 rather irrelevant and hence not worth the space in the present book.

Absolutely, I didn't mean to criticize your book in any way. I actually like well-focused books, and yours is a great example of that!

Regards,

Henning (HoHun)

 

[newsdeskdan]

Oh, that's your book too? I actually bought and read that a couple of years ago, guess I'll have to check it out again now!

Secret Projects of the Luftwaffe: Heinkel He 162 is intended to be the development history without a particular focus on the politics (although there's certainly some of that in it).
The Hated Volksjaeger is a compilation of views, mostly postwar, on the He 162 and the controversy which surrounded it.
At some future point I might combine the two into a big hardback with new cover art along the lines of Heinkel He 162: Development & Politics. That would certainly have Messerschmitt's October 1944 views in it as part of the story rather than being an appendix. The interrogation of Frydag would similarly be slotted into the narrative. If I could find anything contemporary from Tank I'd include it.
There's another dimension to the politics surrounding the He 162 which isn't generally recognised, but which I have tried to bring to the fore: the decision to go ahead with it was made just before Willy Messerschmitt was given responsibility of day fighter development as head of the Special Commission for Day Fighters.
The fact that a day fighter he opposed so vehimently had been rushed into production against his wishes was a real affront to his newfound authority.
Not only that, after years of opposing the single jet fighter on principle (see my Me 262 book), Messerschmitt had finally been persuaded to participate in a design competition for one in July 1944. It would be a next-generation machine powered by a single HeS 011, offering not just material savings but also a tangible performance advantage over the Me 262 (a 262 with HeS 011s was not expected to perform any better than a single-jet fighter with one HeS 011 owing to the seemingly insurmountable compressibility limit).
The design competition for this was steadily progressing - at a rate Messerschmitt presumably approved of - when it was abruptly overridden by the sudden Volksjaeger rush. This no doubt annoyed Messerschmitt, who seems to have felt his company was in with a very real chance of winning the July 1944 competition. He undoubtedly realised that putting the Volksjaeger into production meant even fewer resources would be available for this genuinely advantageous project.

 

[Foo Fighter]

The views I have seen on the 162 are polarised, not much middle ground. Eric thought they were fine for advanced pilots and would be a handful for a Mig 15 but I have yet to see an in depth debate on that. Would it have been of value if the delamination issues had been solved?

 

[T. A. Gardner]

The views I have seen on the 162 are polarised, not much middle ground. Eric thought they were fine for advanced pilots and would be a handful for a Mig 15 but I have yet to see an in depth debate on that. Would it have been of value if the delamination issues had been solved?

The only way to solve the glue bonding problem would have been for Germany to still have a source that could do the Tego glue process. I doubt that that was happening in late 1944. For those not familiar with this process, I'm posting this video by Fairchild Aircraft of their Duramold process which is nearly identical. The Tego process was known pre-war, and copied in other countries. In the US it was called variously Aeromold and Duramold. It is still used today for high strength, exterior plywood, as well as for high quality ones used in furniture.

 

[newsdeskdan]

The views I have seen on the 162 are polarised, not much middle ground. Eric thought they were fine for advanced pilots and would be a handful for a Mig 15 but I have yet to see an in depth debate on that. Would it have been of value if the delamination issues had been solved?

Did you read the book? I looked at the He 162's problems, using contemporary sources, as closely as possible and there is no evidence of glue/delamination issues that I could find. Accident investigation reports of the time, for example those looking at Gotthold Peter's crash in the V1/M1, determined that the cause was longitudinal instability. Peter made a low pass and then manoeuvred - but the aircraft instead entered an extreme roll which could not be recovered. As the aircraft rotated, the aircraft's structural limits were exceeded and the wing disintegrated.
The He 162's problems mostly related to the 3-degree dihedral angle designed into its wings from the outset (which caused a longitudinal stability issue, mostly cured with the fitment of the 45-degree drooped wing endcaps), the positioning and size of its fuel tanks (which caused lateral instability), the poor state of its 003 engine and generally low build quality.

 

[Foo Fighter]

Thank you, I have the book on order so should get it soon-ish.

I watched an interview with Eric Brown, that's the main source for the delamination issue affecting the ta-154 and the He-162, http://www.aviation-history.com/heinkel/he162.html is admitedly not the most ideal source but the initial delamination of the landing gear door, followed by the delamination of the wing leading edge crops up again.

Sorry if I am quoting a poor source.

 

[newsdeskdan]

Thank you, I have the book on order so should get it soon-ish.

I watched an interview with Eric Brown, that's the main source for the delamination issue affecting the ta-154 and the He-162, http://www.aviation-history.com/heinkel/he162.html is admitedly not the most ideal source but the initial delamination of the landing gear door, followed by the delamination of the wing leading edge crops up again.

Sorry if I am quoting a poor source.

Landing gear door yes, wing leading edge no (when I said there was no evidence of delamination, I meant in reference to it being the cause of any of the various fatal accidents - the delaminated landing gear door does get a mention).
As you'll see from the book, the German crash investigators concluded that the chief problem was a combination of longitudinal and lateral instability. They went to great lengths to eliminate both - negating the wing dihedral with end caps, moving fuel tanks around, experimenting with lengthened fuselage, experimenting with longer tailplanes, adding fillets, adding aerodynamic strips to the wing leading edges (I'd never even considered this before reading it in reports - but looking at walkaround videos of surviving airframes - you can clearly see the rather short/thin strip on each wing, close to the fuselage) etc.
Among all this, and the associated reports, there's nothing I could find which says 'this is all fine - but what about the glue?'. You'd think that if the glue was a significant problem, it would be mentioned in those investigation reports. As it stands, the Germans believed instability led to structural failure for Peter. Another fatal accident was attributed to an engine issue resulting in hot gases entering the fuselage and burning though control linkages. Then there was the issue with fuselage warping potentially activating the ejection seat without any instruction from the pilot. And remember, the canopy had to be manually opened before the ejection seat was activated, otherwise...
All that stuff gets a lot of attention. So if the glue was a problem, why isn't that also in those reports? I can only conclude, as the Germans presumably did, that it was not, in fact, a significant problem.

Indeed, I don't know how well known this is, but Gotha designed an alternative wing for the 162 which contained metal fuel tanks. The original Heinkel design used the glue-sealed wooden wings as tanks in themselves. Initially, the sealed wings of the V1 and V2 leaked but this problem was evidently overcome, so it was decided that the Gotha wings were not needed - the metal tank inserts would just add unnecessary weight. This suggests to me, again, that the glue was not regarded as a problem.

 

[Promoter]

Why is nobody discussing the fact that the He 162 needed experienced pilots which were not available anymore for the Luftwaffe in 1945 ?

 

[T. A. Gardner]

Delamination of wooden components on German aircraft during the later half of WW 2 was pretty common. Warping of these also occurred. For example warping was common problem on the Ta 152's flaps that would be sprayed with water in wet / rainy conditions from the landing gear.

Those problems come from a combination of what glues and woods were available at that point.

On the Gotha design, one problem that the Smithsonian noted on theirs is that it showed signs of the wood near the engines scorching in places. That could have been a serious issue...

Using wood for the gas tanks is problematic as the gas is going to soak into the wood, and I'm not sure there's a cure available for that. This came up for the Germans in 1940 with the first drop tanks they developed being wooden to conserve 'strategic' materials.

 

[HoHun]

Hi Dan,

If I could find anything contemporary from Tank I'd include it.

After checking Luftfahrt International #17, I'd say I must have been thinking of Focke-Wulf's "Erläuterungen" ("explanations") for their "standard jet fighter" scheme (on p. 2695), so unfortunately, I'm unable to add anything you haven't seen yet.

I had mentally (and to a degree perhaps mis-)filed this as "Tank largely agrees with Messerschmitt" because the explanation text:

- agrees that the Volkjäger will not be available in larger numbers in spring 1945 (expecting it for the last third of 1945),
- agrees that the Volksjäger will be inferior to upcoming allied jet fighters or have only a short period of operational utility due to poor performance,
- acknowledges (like Messerschmitt) the preparation for series production as a major factor that should not be undertaken for a type that is only of utility for a brief period,
- suggests the "standard jet fighter" with the final (single) HeS 011 engine as Me 262 replacement, which Messerschmitt suggested too (of course, he probably wasn't explicitely thinking of the Focke-Wulf type! ;-))

Translating the conclusion:

"All of these advantages for the suggested standard jet fighter are being achieved just by increasing the production effort per airframe by a mere 20 to 25 percent compared to the people's aircraft, which due to its inferior performance is going to be fit for combat operations only for a few months.

If one assumes that a superior single-jet fighter has to be developed, the total effort will be much lower by creating a standard jet fighter according to the above suggestion. The difference in performance between Volksjäger with BMW 003 and standard jet fighter with 003 is irrelevant for the short period of operations."

So basically, Focke-Wulf is in full agreement with many of the points Messerschmitt made (and in opposition to none of them), suggesting a very similar solution - gearing up for production of a HeS-011-powered fighter to finally replace the Me 262. Unlike Messerschmitt, Focke-Wulf is ready to build a Volksjäger-type aircraft though - but only by putting a low-performance engine in the high-performance aircraft.

That's a bit more diplomatic than Messerschmitt's approach, but probably not by much And as we know, it failed. Still, I think it's worth noting that Focke-Wulf thought that their case for the standard jet fighter was so strong that the attempt to sell it to the Luftwaffe was worthwhile.

Regards,

Henning (HoHun)

 

[newsdeskdan]

Hi Dan,

If I could find anything contemporary from Tank I'd include it.

After checking Luftfahrt International #17, I'd say I must have been thinking of Focke-Wulf's "Erläuterungen" ("explanations") for their "standard jet fighter" scheme (on p. 2695), so unfortunately, I'm unable to add anything you haven't seen yet.

I had mentally (and to a degree perhaps mis-)filed this as "Tank largely agrees with Messerschmitt" because the explanation text:

- agrees that the Volkjäger will not be available in larger numbers in spring 1945 (expecting it for the last third of 1945),
- agrees that the Volksjäger will be inferior to upcoming allied jet fighters or have only a short period of operational utility due to poor performance,
- acknowledges (like Messerschmitt) the preparation for series production as a major factor that should not be undertaken for a type that is only of utility for a brief period,
- suggests the "standard jet fighter" with the final (single) HeS 011 engine as Me 262 replacement, which Messerschmitt suggested too (of course, he probably wasn't explicitely thinking of the Focke-Wulf type! ;-))

Translating the conclusion:

"All of these advantages for the suggested standard jet fighter are being achieved just by increasing the production effort per airframe by a mere 20 to 25 percent compared to the people's aircraft, which due to its inferior performance is going to be fit for combat operations only for a few months.

If one assumes that a superior single-jet fighter has to be developed, the total effort will be much lower by creating a standard jet fighter according to the above suggestion. The difference in performance between Volksjäger with BMW 003 and standard jet fighter with 003 is irrelevant for the short period of operations."

So basically, Focke-Wulf is in full agreement with many of the points Messerschmitt made (and in opposition to none of them), suggesting a very similar solution - gearing up for production of a HeS-011-powered fighter to finally replace the Me 262. Unlike Messerschmitt, Focke-Wulf is ready to build a Volksjäger-type aircraft though - but only by putting a low-performance engine in the high-performance aircraft.

That's a bit more diplomatic than Messerschmitt's approach, but probably not by much And as we know, it failed. Still, I think it's worth noting that Focke-Wulf thought that their case for the standard jet fighter was so strong that the attempt to sell it to the Luftwaffe was worthwhile.

Regards,

Henning (HoHun)

It's rather a shame that Luftfahrt International #17 chopped off the fourth column, on the right, of Focke-Wulf's Erläuterungen, which depicts the other design tendered, as well as the accompanying graphs. The document was subsequently copied by other publications - none of which knew about the fourth column. I was therefore very surprised to see it when I discovered the complete original document for myself. It is of course printed on p58 of the book.

 

[T. A. Gardner]

The flaps thing is mentioned in Monogram 24 Close up Ta 152 about the flap issue.

 

[newsdeskdan]

Delamination of wooden components on German aircraft during the later half of WW 2 was pretty common. Warping of these also occurred. For example warping was common problem on the Ta 152's flaps that would be sprayed with water in wet / rainy conditions from the landing gear.

Those problems come from a combination of what glues and woods were available at that point.

On the Gotha design, one problem that the Smithsonian noted on theirs is that it showed signs of the wood near the engines scorching in places. That could have been a serious issue...

Using wood for the gas tanks is problematic as the gas is going to soak into the wood, and I'm not sure there's a cure available for that. This came up for the Germans in 1940 with the first drop tanks they developed being wooden to conserve 'strategic' materials.

Absolutely. It wasn't an aircraft designed with any sort of shelf life in mind. The Me 262 was designed for greater longevity but sadly it wouldn't get it, owing to the type's apparently appalling attrition rate.

 

[newsdeskdan]

Why is nobody discussing the fact that the He 162 needed experienced pilots which were not available anymore for the Luftwaffe in 1945 ?

The book is about the type's development. I deliberately avoided covering the operational service side, since that's been recounted elsewhere in more detail than I could manage using primary sources alone - which is what my book is based on.
I do cover the two trainer variants that were under development when the war ended, however.

 

[newsdeskdan]

On the Gotha design, one problem that the Smithsonian noted on theirs is that it showed signs of the wood near the engines scorching in places. That could have been a serious issue...

Definitely. As I mentioned, one of the prototypes (M3) was lost when hot engine gases entered the fuselage and burned through control cables.

 

[Foo Fighter]

The last thing I have to mention on the glue front is that the Ta-154 was not popular within the RLM, the glue came from one factory and these supplies could have been in the hands of the He-162 team (Given priority) prior to the factory making the system being completely destroyed. The Ta-154 which had to be copnstructed with an alternative suffered heavily so possibly the 162 is being lumped in there for having wooden construction.

As we are all aware, not a lot of folk out there are as meticulous as our Dan.

Really looking forward to these books arriving.

 

[T. A. Gardner]

The last thing I have to mention on the glue front is that the Ta-154 was not popular within the RLM, the glue came from one factory and these supplies could have been in the hands of the He-162 team (Given priority) prior to the factory making the system being completely destroyed. The Ta-154 which had to be copnstructed with an alternative suffered heavily so possibly the 162 is being lumped in there for having wooden construction.

As we are all aware, not a lot of folk out there are as meticulous as our Dan.

Really looking forward to these books arriving.

This was the aforementioned Tego process factory that had--in Germany--a patent giving exclusive rights to that company to that process. When the factory was destroyed, the company couldn't rebuild and nobody else was granted the rights to do the process. This wasn't an isolated case, but rather the rule in Germany at the time.

 

[Foo Fighter]

I am aware, just wondering if the 162 factory had sufficient stocks while the other factory had the story of the other little piggie.

 

[newsdeskdan]

The glue used for the He 162's wings is referred to as 'P 600', a phenol resin produced by Dynamit at Troisdorf. I don't have any details of Heinkel's P 600 testing but I do have four or five documents on it from Focke-Wulf. That company was engaged in testing numerous different compounds and variants of it from at least summer 1943 and certainly there is a document from January 1945 which reports very positive results using it. Basically, I think that by the time the He 162 was being made, at least one serviceable replacement for the original Tegofilm (produced by Goldmann at Wuppertal, whose Tegofilm factory was apparently destroyed by the RAF on the night of May 20/21, 1944) had been found. Incidentally, while Heinkel were using P 600, I have other reports on suitable alternatives from Focke-Wulf. Evidently something called 'Buna 32 A' produced by IG Farben at Leverkusen also gave better results than Tegofilm during tests conducted in November 1944.
None of this is in the book because - as I've said - there just doesn't seem to have been a glue problem at the time when the He 162 was being made. Perhaps if I end up creating a Heinkel He 162: Development & Politics book, I'll explain more fully about P 600, Tegofilm etc. to the extent that I'm able to do so using primary source reference material.

 

[T. A. Gardner]

The problem with the phenol resin type glues is mostly one of improper application. If you apply it too thickly, it creates a weak bond between the surfaces much like applying too much 'super' glue does. In thick applications, phenol resins crystalize between the layers instead of bonding them creating a weak surface.
The Germans also used formaldehyde-based glues that could accept filler materials and act as gap fillers.

My suspicion is that most of the bonding problems the Germans encountered late in the war with wood glues were due to improper application (intentional or accidental--after all, slave and impressed foreign workers were being used in many cases) or application in conditions of temperature, humidity, etc., that were less than ideal.

There could also be issues with the wood(s) selected in quality, type, and seasoning. That is, the wood could have been poor quality, or too green, too dry, or whatever.

These are quality control issues that likely were being encountered increasingly frequently as the war went on. Disgruntled workers, workers deprived of proper rest or food (including those who did want to do a good job), or being poorly trained and rushed into doing semi-skilled production tasks, could all contribute to a poor quality product.

 

[newsdeskdan]

The problem with the phenol resin type glues is mostly one of improper application. If you apply it too thickly, it creates a weak bond between the surfaces much like applying too much 'super' glue does. In thick applications, phenol resins crystalize between the layers instead of bonding them creating a weak surface.
The Germans also used formaldehyde-based glues that could accept filler materials and act as gap fillers.

My suspicion is that most of the bonding problems the Germans encountered late in the war with wood glues were due to improper application (intentional or accidental--after all, slave and impressed foreign workers were being used in many cases) or application in conditions of temperature, humidity, etc., that were less than ideal.

There could also be issues with the wood(s) selected in quality, type, and seasoning. That is, the wood could have been poor quality, or too green, too dry, or whatever.

These are quality control issues that likely were being encountered increasingly frequently as the war went on. Disgruntled workers, workers deprived of proper rest or food (including those who did want to do a good job), or being poorly trained and rushed into doing semi-skilled production tasks, could all contribute to a poor quality product.

There seem to have been a lot of products that were continuously evolved over a long period of time. So the P 600, Tegofilm, Polystahl, Aviatin-E etc. of, say, August 1943, were not exactly the same as the substances using those names in January 1945. Looking through my Focke-Wulf materials, I have to say that there are literally dozens of surviving reports on tests involving glues, resins, plywood, steel etc. This is almost certainly because the British captured Focke-Wulf's structures testing facility at Detmold intact, including all of its paperwork. All this, however, is lab work - as you say, conditions in the field combined with manufacturing imprecision may well have impacted in-service aircraft. I say 'may well have' because not that many He 162s were made and those that were evidently didn't last long enough in service for any noticeable glue/wood-related issues to surface.