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

[HoHun]

Hi Dan,

The glue used for the He 162's wings is referred to as 'P 600', a phenol resin produced by Dynamit at Troisdorf.

Oh, that's interesting! Coincedentally, I walked along one edge of the vast factory grounds recently, with the relics on the other side of the old-fashioned concrete-post mesh fence giving a definite "lost place" vibe. I have no idea if these abandoned buildings all go back to the WW2 era, but I wouldn't be surprised if they did.

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.
...
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.

Incidentally, I recently rediscovered that Focke-Wulf document while looking for something else. Here's a close-up of the design which appears in that fourth column.

 

[HoHun]

Hi again,

• 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.

• 
  
  I just came across a document on https://invenio.bundesarchiv.de (signature R 3/3900) which confirms Messerschmitt's point about Luftwaffe demands. It's a letter from 3rd of January 1945, drafted by Lucht and signed by F.d.R. Fleischhauer, adressed at the Special Development Commission Bad Weather and Night Fighters (headed by Kurt Tank), stating:
  
  - Currently, the limited endurance of German fighter aircraft is a serious tactical disadvantage.
  - It's also uneconomic to operate short-endurance fighters, since a larger proportion of the fuel is used for forming up and climb.
  
  The requirements formulated are:
  
  - Fighter aircraft should have enough internal fuel for 3 hours at maximum continuous power, including 30 min combat power.
  - Drop tanks should add another 60 - 90 min endurance.
  - Jet fighters should be modified to meet the same endurance requirements.
  - The Ta 152 should be delivered on time and with the full internal fuel capacity of 1100 L right from the start.
  - Renewed attempts at increasing the flight time of the Me 109 and the Fw 190 by increasing internal tankage. Endurance should at least be twice the current value.
  - No deterioration in performance as result of the increase in fuel load.
  
  Especially the doubling of the Me 109's and Fw 190's fuel was demanded for spring of 1945. Of course, that's not really a definition of requirements, but plain wishful thinking.
  
  Still, the He 162 was designed for a 30 min endurance requirement, which was maybe half of that of the endurance of the two propeller-driven fighter types, which were considered to have at best half the endurance actually required.
  
  Regards,
  
  Henning (HoHun)

 

[elmayerle]

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.
...
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.

Incidentally, I recently rediscovered that Focke-Wulf document while looking for something else. Here's a close-up of the design which appears in that fourth column.

View attachment 686938

Looks like the one that's been kitted as the "PTL Flitzer".

 

[elmayerle]

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.

"Buna 32A" almost sounds like it has a connection with synthetic rubber (Buna-N et al.).

 

[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.
...
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.

Incidentally, I recently rediscovered that Focke-Wulf document while looking for something else. Here's a close-up of the design which appears in that fourth column.

View attachment 686938

Looks like the one that's been kitted as the "PTL Flitzer".

It was known internally as 'Peterle'. The only Focke-Wulf jet/PTL designs to get 'names' were Huckebein, Flitzer and Peterle.

 

[HoHun]

Hi Dan,

View attachment 686938
Looks like the one that's been kitted as the "PTL Flitzer".

It was known internally as 'Peterle'. The only Focke-Wulf jet/PTL designs to get 'names' were Huckebein, Flitzer and Peterle.

Oh, I didn't realize before that "Peterle" is a phonetic "interpretation" of PTL! :-D Neat, I'm not aware of any other German aircraft (nick-)name constructed in that way.

"Huckebein" alludes to Wilhelm Busch's "Hans Huckebein the Unlucky Raven": https://de.wikipedia.org/wiki/Hans_Huckebein,_der_Unglücksrabe#/media/Datei:Huckebein.jpg

"Flitzer" is a colloquial term for a small sports car. The name also has a connection to Messerschmitt, who after WW2 produced a micro car that was a development of the earlier "Fend Flitzer": https://en.wikipedia.org/wiki/Fend_Flitzer

Regards,

Henning (HoHun)

 

[newsdeskdan]

Hi Dan,

View attachment 686938
Looks like the one that's been kitted as the "PTL Flitzer".

It was known internally as 'Peterle'. The only Focke-Wulf jet/PTL designs to get 'names' were Huckebein, Flitzer and Peterle.

Oh, I didn't realize before that "Peterle" is a phonetic "interpretation" of PTL! :-D Neat, I'm not aware of any other German aircraft (nick-)name constructed in that way.

"Huckebein" alludes to Wilhelm Busch's "Hans Huckebein the Unlucky Raven": https://de.wikipedia.org/wiki/Hans_Huckebein,_der_Unglücksrabe#/media/Datei:Huckebein.jpg

"Flitzer" is a colloquial term for a small sports car. The name also has a connection to Messerschmitt, who after WW2 produced a micro car that was a development of the earlier "Fend Flitzer": https://en.wikipedia.org/wiki/Fend_Flitzer

Regards,

Henning (HoHun)

I didn't believe that Huckebein, Flitzer and Peterle (which does indeed seem to be a nice phonetic interpretation of PTL) were real until I saw them in the primary source documents for myself. I later discovered that Heinz Conradis (who was a manager at Focke-Wulf during the war) mentions both Huckebein and Flitzer in his biography of Kurt Tank - Forschen und Fliegen.

 

[Abbetpa]

Dear Dan,

I would have liked to contact you via a private conversation, but I didn't manage to create one... Never mind, I'll try to do it directly in this thread, which is right on topic!

I bought (I even have 2 copies...) and read with great interest your book "Secret Projects of the Luftwaffe: Heinkel He 162".

I have been interested for many years in this very special aircraft, both in the history of its design and manufacture as well as in its operational actions.

I was particularly pleased to see the construction plans you published (chapter 4, pages 77 to 95). The details and dimensions are very useful to me, as I am in the process of redrawing precise 3 view plans and their various components.

Unfortunately the reproductions in your book are too small and not sharp enough to easily read the dimensions and understand the design of the different parts.

Can you give me the references and sources of the archives where you could obtain these documents? If they are not available, can you provide me with better copies?

I thank you in advance for your answer (if you prefer in private conversation) and I am already looking forward to discovering the always very high quality content of your next publications.

Best regards
Pascal A.

 

[overscan (PaulMM)]

Off topic Me 262 discussion moved here: https://www.secretprojects.co.uk/threads/me-262-a-waste-of-resources.41993/

 

[riggerrob]

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.

Good points.
Anything less then perfect application of glue or sealants would allow water or fuel to seep into the plywood structure. Fuel saturated wood is an obvious fire hazard.
Water saturated wood would soon delaminate whenexposed to freezing temperatures (winter weather or flying at high altitudes).
While we crucize poor-quality German yours, remember that Allied airplanes suffered similar problems such that Allies only advantage was much larger industrial capacity that could quickly replace deteriorated wooden airframes.

For example, when wooden dH Mosquitos got saturated with water, they got heavier and reflected much larger radar returns.
Tropical white ants (aka. termites) enjoyed the taste of British glues so quickly ate RAF Mosquito squadrons out of house and home. Today only a handful of Mosquitos are airworthy and most of them are ground-up restorations incorporating all new wood plus salvaged metal parts.

In a second example, Canadian-built Anson Mark V had fuselages molded from phenolic-resin impregnated plywood. Post war most were scrapped to salvage their engines (P&W R-985) and instruments. Plywood airframes were left to rot behind the barn. Today only a handful of Anson Mark V survive in museums.

 

[Keith C]

Dear Dan,

I would have liked to contact you via a private conversation, but I didn't manage to create one... Never mind, I'll try to do it directly in this thread, which is right on topic!

I bought (I even have 2 copies...) and read with great interest your book "Secret Projects of the Luftwaffe: Heinkel He 162".

I have been interested for many years in this very special aircraft, both in the history of its design and manufacture as well as in its operational actions.

I was particularly pleased to see the construction plans you published (chapter 4, pages 77 to 95). The details and dimensions are very useful to me, as I am in the process of redrawing precise 3 view plans and their various components.

Unfortunately the reproductions in your book are too small and not sharp enough to easily read the dimensions and understand the design of the different parts.

Can you give me the references and sources of the archives where you could obtain these documents? If they are not available, can you provide me with better copies?

I thank you in advance for your answer (if you prefer in private conversation) and I am already looking forward to discovering the always very high quality content of your next publications.

Best regards
Pascal A.

I'm also trying to hunt down high-resolution images of the original Heinkel He162 blueprints. I contacted the NASM archives but haven't been able to determine which (if any) of the reels in their archives contain the blueprints shown in Dan Sharp's book.

Does anybody here know the specific reel numbers that contain blueprints? Or even better, have the drawings and are willing to share them.

--Keith

 

[T. A. Gardner]

Good points.
Anything less then perfect application of glue or sealants would allow water or fuel to seep into the plywood structure. Fuel saturated wood is an obvious fire hazard.
Water saturated wood would soon delaminate whenexposed to freezing temperatures (winter weather or flying at high altitudes).
While we crucize poor-quality German yours, remember that Allied airplanes suffered similar problems such that Allies only advantage was much larger industrial capacity that could quickly replace deteriorated wooden airframes.

For example, when wooden dH Mosquitos got saturated with water, they got heavier and reflected much larger radar returns.
Tropical white ants (aka. termites) enjoyed the taste of British glues so quickly ate RAF Mosquito squadrons out of house and home. Today only a handful of Mosquitos are airworthy and most of them are ground-up restorations incorporating all new wood plus salvaged metal parts.

In a second example, Canadian-built Anson Mark V had fuselages molded from phenolic-resin impregnated plywood. Post war most were scrapped to salvage their engines (P&W R-985) and instruments. Plywood airframes were left to rot behind the barn. Today only a handful of Anson Mark V survive in museums.

The only process that was really viable for aircraft manufacture was the Tego glue (in the US called variously Aeromold or Duramold) process that was used initially on the Ta 154. In the US, Fairchild and Timm aircraft used essentially the same process to build the AT 21 Gunner and N2T Tutor trainers.

The process made waterproof to water resistant plywood that wouldn't delaminate. Some of the original Timm N2T's are still airworthy today and flying.

 

[Archibald]

Oh, I didn't realize before that "Peterle" is a phonetic "interpretation" of PTL!

L'était surtout bon à péter.. le pilote (excelled mostly at breaking... its pilot). Lame linguistic pun fully assumed.