The Surprising Hannover and Halberstadt CLs.

[Akuma]

A little tidbit of history. Germany developed a number of reconnaissance (CL) aircraft during WWI and among these were the Halberstadt and Hannover CL types. Up until then all reconnaissance aircraft needed the protection of fighters during their missions. However these two were found to be of such high performance as to be able to take on any fighters that they might encounter. It might help to think of these as versions of the Bristol Fighter. Before a reconnaissance flight one pilot was tasked with protecting the other after mission completion. If attacked on the way to the mission area both planes acted as fighters. If attacked after recon, the plane with the info would turn back to their lines while the other would cover his retreat. When the need for ground attack became greater the German Air Service not only asked for special designs but tested their existing aircraft to see if any were suitable. It turned out that the Hannover and Halberstadt were so robust as to be able to take punishment to a greater degree than other aircraft then available. They were put into service as ground attackers in addition to recon and air fighting. In the years following WWI, I do not know of any aircraft that was able to act in all three capacities without some limiting modification.
Recommended reading: 'Schlact-Flieger" by Duiven & Abbott. Publishers: Schiffer Military History, Schiffer Publishers Ltd.

 

[Thumpalumpacus]

Don't forget the Walfisch. It was perhaps the best two-seater of the war in terms of being able to fight its way out of trouble.

 

[GrauGeist]

The first purpose built ground attack was the German's AEG J.1a introduced in 1917.
It was built with a welded steel frame and an armored cockpit.
It was armed with two fixed 7.92mm LMG 08/15 MGs aimed downward at a 45° angle for strafing. It also had a flexible 7.92mm MG in the rear for defense.

 

[Akuma]

Don't forget the Walfisch. It was perhaps the best two-seater of the war in terms of being able to fight its way out of trouble.

Always liked the lines of that bird. With more power and a better airfoil it might have served longer as a front line airplane.

 

[Thumpalumpacus]

Always liked the lines of that bird. With more power and a better airfoil it might have served longer as a front line airplane.

It could certainly use more power, but what plane of the era couldn't?

I don't know enough about the wing design to offer an informed opinion.

Forgive a gaming reference, but on RB2-3D it's a bitch.

 

[Akuma]

It could certainly use more power, but what plane of the era couldn't?

I don't know enough about the wing design to offer an informed opinion.

Forgive a gaming reference, but on RB2-3D it's a bitch.

It would be safe to say that the first 'good' airfoils were the ones that the people back then called "Fokker's Thick Wings". I am not aware of anyone else having them before Fokker but there might have been one or two out there. Many said that the fokker wings were detrimental to performance and would never lead anywhere. This is right in line with people saying that aerial reconnaissance was impossible since, at speeds above 40 mph a human being would see nothing but a blur. After the war of course everybody realized their mistake and now we have that airfoil found everywhere. As for the Walfisch, a BMW 185 hp engine with Fokker wings like the D-7s could have given it what it needed to remain active maybe until 1918.
Used to play RB2-3D. Could get surprisingly immersive. Don't know how it compares to other WWI flyers.

 

[Thumpalumpacus]

Don't know how it compares to other WWI flyers.

I've been meaning to get into RoF. I have it in hard copy but it will not work on my Win10 laptop, so I've gotta find a patch.

I knew Fokkers were known for their thick wings. I was under the impression, though, that all planes of the era had relatively high T-C ratios. Thanks for the info!

 

[tyrodtom]

Junkers actually done the first research on the thick airfoil,, but took too long bringing anything into production.
Plus he insisted on combining it with his all metal construction, which the authorities were slow to accept.

Fokker copied the thick wing airfoil in conventional construction, and Hugo Junkers was pissed at Fokker forever..

 

[Akuma]

Junkers actually done the first research on the thick airfoil,, but took too long bringing anything into production.
Plus he insisted on combining it with his all metal construction, which the authorities were slow to accept.

Fokker copied the thick wing airfoil in conventional construction, and Hugo Junkers was pissed at Fokker forever..

You're right, I forgot about when the German Air Service insisted that Fokker and Junkers team up. I remember reading that it was after Fokker broke with Junkers that he started using the thick wing that Junkers had been developing.

 

[nuuumannn]

Fokker copied the thick wing airfoil in conventional construction,

Just a wee bit of perspective. The "Fokker" wing was not specifically about its thickness but the fact it was entirely cantilever, the basis being built around an integral box spar arrangement without external bracing in entirely wooden construction. The wing design was actually Reinhold Platz's idea rather than Fokker's and was first applied on the Fokker V 1 prototype designed entirely by Platz and conceived in 1916 and completed in January 1917, which exhibited more than a few advanced features for its time. The prototype of the Dr I was the V 3, which had entirely cantilever wings, but due to wing flutter these were externally braced in the V 4, which essentially became the production Dr I standard.

Junkers' work was entirely in metal, which set it aside from Platz, and almost everyone else at the time, again it was a cantilever wing, but designed around Junkers' method of construction, which comprised a warren truss cage type thing making up the interior structure, with an exterior skin attached in his first few designs, beginning with the J 1. This changed to the corrugated outer covering familiar as a Junkers hallmark, with external corrugated bracing on sheets of skin that attached to multiple spars in the wings, but without ribs; all internal stiffening in the wing was fitted to the wing skins, except for the spars.

 

[tyrodtom]

The Junkers J 1 first flew in December of 1915. Since Junkers had no aircraft production experience, IdFlieg mandated a partnership between Junkers and Fokker.
Fokker saw the advantages of the thick airfoil , and with his designers, Rienhold Platz among them, came up with a thick airfoil but in wood construction. Came up with the Fokker V 1, and V 2 , in 1916 and finally the V 4 which developed into V5, or DR1 in late 1916 or early 1917.
I think it's evident the original idea was not from Fokker, or any of his employees .
Hugo Junkers sued Fokker, the lawsuit was to drag on until 1940 before it was settled.

 

[nuuumannn]

I think it's evident the original idea was not from Fokker, or any of his employees .

See below...

 

[nuuumannn]

The Junkers J 1 first flew in December of 1915. Since Junkers had no aircraft production experience, IdFlieg mandated a partnership between Junkers and Fokker.
Fokker saw the advantages of the thick airfoil , and with his designers, Rienhold Platz among them, came up with a thick airfoil but in wood construction. Came up with the Fokker V 1, and V 2 , in 1916 and finally the V 4 which developed into V5, or DR1 in late 1916 or early 1917.
I think it's evident the original idea was not from Fokker, or any of his employees .
Hugo Junkers sued Fokker, the lawsuit was to drag on until 1940 before it was settled.

Actually, the lawsuit wasn't specifically about thick wings, it was about the use of cantilever construction, as I mentioned. The original intent was that Junkers and Fokker's joint factory was to build Junkers all-metal aircraft, but Fokker wanted rights to build a cantilever wing, which his designer's did, with the box spar design, which was very different to Junkers' design, as I mentioned. Junkers believed that the patent that Fokker had paid for covered only the construction of Junkers aircraft, but Fokker believed he paid for rights to cantilever construction, which Junkers objected to. It wasn't about the wing thickness at all.

Correction, the box spar construction technique was patented by a Swedish engineer named Forssman who was a rep for a plywood firm.

 

[tyrodtom]

Cantilever construction was not possible with thin wings with the materials then available.
It wasn't just the box spar that made it possible, it was the box spar, in conjunction with the vertical depth of a thick wing that made a cantilever wing that was strong enough .

 

[nuuumannn]

It wasn't just the box spar that made it possible, it was the box spar, in conjunction with the vertical depth of a thick wing that made a cantilever wing that was strong enough .

Obviously, but the lawsuit was about the use of cantilever wings, not specifically their thickness. Let's not forget that Junkers aircraft did not use a box spar. The lawsuit was actually quite complex and wasn't as simple as accusing Fokker of ripping Junkers off because Fokker actually paid for the design rights which included the use of the cantilever wing. Fokker's ideas and application for cantilever wings came from various sources, which independently owed nothing to Junkers at all, but for the concept of a cantilever wing. Fokker did this often, applying what he had learned from other manufacturers and applied it to his own aircraft designs. Part of the animosity Junkers expressed toward Fokker came from the fact he didn't like Fokker, the polar opposite in personality.

The anger Junkers displayed came after their meeting at Dessau, where Fokker asked to find out all he could about the cantilever wing, Junkers exploded and accused him of using his experience at Dessau for his own purpose, but an agreement was drawn up by Fokker's law firm in Berlin, with the inclusive use of techniques based on Junkers cantilever construction.

 

[tyrodtom]

Obviously, but the lawsuit was about the use of cantilever wings, not specifically their thickness. Let's not forget that Junkers aircraft did not use a box spar. The lawsuit was actually quite complex and wasn't as simple as accusing Fokker of ripping Junkers off because Fokker actually paid for the design rights which included the use of the cantilever wing. Fokker's ideas and application for cantilever wings came from various sources, which independently owed nothing to Junkers at all, but for the concept of a cantilever wing. Fokker did this often, applying what he had learned from other manufacturers and applied it to his own aircraft designs. Part of the animosity Junkers expressed toward Fokker came from the fact he didn't like Fokker, the polar opposite in personality.

The anger Junkers displayed came after their meeting at Dessau, where Fokker asked to find out all he could about the cantilever wing, Junkers exploded and accused him of using his experience at Dessau for his own purpose, but an agreement was drawn up by Fokker's law firm in Berlin, with the inclusive use of techniques based on Junkers cantilever construction.

The fact that Junkers J 1 flew almost a year before any of Fokker's box spar design's managed a flight suggests otherwise.

 

[nuuumannn]

The fact that Junkers J 1 flew almost a year before any of Fokker's box spar design's managed a flight suggests otherwise.

It's well known that Fokker looked at what Junkers was doing and applied it, but the designs of wing and their construction were so vastly different to one another, it's like saying that every subsequent tail dragger monoplane aircraft looks like a Bleriot XI, so everyone ripped Bleriot off. Let's not forget that Fokker paid for the rights to Junkers' design concepts, which included cantilever wing construction and their subsequent application. Junkers allowed this as long as he held patent rights to the concept.

"The stated aim of the Fokker-Junkers Works was to start production of the all-metal aircraft designed by Junkers, for which they would now hold all patent rights. For Junkers the new enterprise meant financial support of his research in aerodynamics. He also retained the right to use his patents outside the joint venture in Junkers & Company. For Fokker the matter was more complicated: apart from the right (or duty) to start up a production line of Junkers aircraft, he received the coveted patent rights for Junkers's cantilever wing construction. For the sum of 250,000 marks ($43,330) plus 9 percent of the net price of every airplane sold, Fokker Flugzeugwerke in Schwerin could henceforth make use of the knowledge gained from the linkup."

From here: Fokkers and Junkers

 

[tyrodtom]

What Junkers did in 1915 was so radically different from anyone else's wing design he might have though the whole concept of a thick wing belonged to him.

But if he sold the rights to Fokker, what was the grounds for his lawsuit ?

 

[tyrodtom]

Fokkers and Junkers also states the lawsuit was settled in 1940, but no details .
Seeing as how Holland was occupied by Germany in 1940 , I can guess in whose favor it was settled .

 

[nuuumannn]

But if he sold the rights to Fokker, what was the grounds for his lawsuit

That's a good question, Tom. From what I've read it seems petty behaviour and a mistrust of each others intentions led to ill feeling between them, they did not get along, but Junkers saw Fokker do well in the Idflieg competitions and maybe felt hard done by because of Fokker's success? That's a guess of course.

The lawsuit from what I can gather was due to patent infringement, which seems odd, all things considered.