The Fafnir
A life history of a 1930's German Sailplane and of it's pilot, Günther Groenhoff

A decade of research by
Vince Cockett


The Fafnir Designer
Alexander Lippisch - (Nov. 2nd 1894 to Feb. 11th 1976)

Alexander Martin Lippisch was a German aerodynamicist and glider designer. Today the broader aviation community mainly remembers him for his pioneering development of tailless aircraft culminating in the rocket powered Messerschmitt Me.163

 Lippisch was born in Munich on 2nd November 1894.  He later recalled that his interest in aviation was first kindled in September 1909 when he saw a demonstration flight by Orville Wright in Berlin. He had planned to follow in his Father’s footsteps and enter art school, when World War 1 intervened. During his service in the German Army between 1915 -1918, Lippisch had the chance to fly as an aerial photographer and map maker.

 After the war, Lippisch worked for a while with the Zeppelin Company and it was then that he began his life-long interest in tailless aircraft.

In 1921 his first tailless design, the Lippisch- Espenlaub E2 (seen below) was constructed. Toward the end of 1924 he was appointed Director of the Aeronautical Department of the Rhön Rossiten Gesellschaft (RRG), a research institute  which was to promote the development of gliders and gliding. This allowed him to built another tailless machine called Experiment in 1925 and development continued with the Storch series of high wing tailless gliders which by 1929 had produced a glider with good handling characteristics.

 However, Lippisch had a parallel and more mainstream career as a designer of many conventional, well known gliders. Between 1921 and 1929 he designed some twenty different types including the famous trainers - Hols der Teufel (1923), Zogling (1926), Prufling  (1926), Falke (1927) and the more advanced Professor (1928) that together formed the backbone of German gliding in its formative years.

Although by 1928 Lippisch had possibly designed more gliders than any other individual in Germany, they were the unglamorous workhorses of the training schools. His Professor was intended to offer the schools the plans to build a good, solid sailplane with a decent good performance, that would be much cheaper to build than the more sophisticated designs of the Darmstadt school, such as the Westpreussen, with their oval monocoque ply fuselages and cantilever wings. However the Professor was not easy to fly and was prone to tip stalling to the extent that the outer wing panels were later redesigned.

As yet Lippisch had not designed a truly high performance sailplane.

 Kronfeld achieved some good flights with the prototype Professor and asked Lippisch to design him a more sophisticated version, in exchange for his work at the RRG. It seems that Lippisch could never find the time or wouldn’t make the time, to honour that commitment. This and various later events created considerable animosity between the two men.

 Contrary to much that has been written, Kronfelds new sailplane, the Wien, was not designed by Lippisch !!!!  It was actually designed by a student at the RRG called Pohorille and the drawings themselves were signed off by Lippischs assistant Hans Jacobs (later the designer of the Rhonadler, Rhonbussard, Rhonsperber, Reiher etc). The extent of Jacobs involvement is unknown.

 Completed in the autumn of 1928, the Wien had a very successful career, breaking records and participating in many displays,  however in the same year,

Dr August Kupper at the Munchen Akaflieg constructed the remarkable Mu.3 Kakadu. Its 19.56 metre span was comparable to the Wien but the aspect ratio was somewhat higher at a remarkable 22.2.  With a clean, almost straight taper cantilever wing mounted on a short pylon above a very clean fuselage, Kakadu must have immediately made the strut braced Wien look outdated. In retrospect, Kakadu can be regarded as the first modern sailplane.

 What impact Kakadu made on Lippisch is unknown but he must have felt under pressure. No one was really interested in his tailless designs which offered no improvement over conventional types and the Professor sailplane could be considered a failure due to its difficult handling. As the national institution, the RRG was in the embarrassing position of not having a sailplane that could be considered competitive for the next Rhon meeting.

 Lippisch’s answer was the Fafnir, a huge leap from the slab sided, strut braced Professor. It emerged as a pure cantilever 19.0 metre sailplane of very elegant aerodynamic form. It is possible that the pylon carrying Kakadu’s long span wing was considered (or found) to be vulnerable to damage.  By mounting the Fafnir’s wing directly onto the top of the fuselage Lippisch found a better structural solution, although this reduced the wingtip’s ground clearance. Rather than using dihedral to solve this problem, the elegant gull wing was used and set a fashion that dominated sailplane design for more than a decade.

Above - The Wien flown by Kronfeld
Below - Kronfeld and Groenhoff
Legend has it that the small fuselage was designed specifically for Groenhoff and this may be the case. However when design of the Fafnir began in late 1929 it was Kronfeld that that was the famous pilot and Groenhoff was just receiving recognition for his talents. In fact both men were of similar stature. There were other complications. Kronfeld had angered Lippisch by having the Wien designed elsewhere (and later revealing Lippisch had NOT designed it). The politics of the day were complex and relations with Austria were strained and Kronfeld as an Austrian was referred to as ‘an unloved foreigner’. In an era of rampant anti Semitism, Kronfelds features may have raised suspicion and in 1931 it was revealed he had Jewish ancestry.

 Today we cannot know exactly what happened but ultimately the Fafnir became Groenhoff’s sailplane – but the extent to which it was purely Lippisch’s design is open to question. Design work began in the winter of 1929/30 and construction began in 1930. Again Lippisch couldn’t ‘find the time’ to complete the project and Groenhoff frequently had to search him out to answer questions on the design details. The construction was quite technically challenging and Groenhoff also had to seek help from Heini Dittmar and Hans Jacobs.

 In Hans Jacobs we see a link between the Wien in which he was involved and the Fafnir, where the extent of his input is unknown. It is however notable that the elegant form of the Fafnir was quite unlike any sailplane or aircraft that Lippisch ever designed either before or after.

So, why was his Fafnir project given its name? Popular belief was that all the intricate planking on the fuselage was likened to the scales of a Dragon, however there is a more truthful story:

‘Fafnir’ was a colossus from an old German myth called "Nibelungensaga" who stood for nature, power and barbarism. He had a brother by the name of ‘Fasold’ who stood for intellectuals, studies and culture This story is also a part of Wagner´s epic musical piece ‘Rheingold’. In the story, the brothers fought each other with Fafnir eventually killing his brother after which he changed his image to that of a dragon to protect the treasure of the Nibelung. He would in turn be killed later by the German mythical hero Siegfried who would then bath in Fafnir´s blood to become invincible except for a small part of his shoulder.

Robert Kronfeld, the famous glider pilot and rival to Günter Groenhoff, believed that the Fafnir was not very well constructed and that it took records only because of the genius of its pilot Groenhoff. Kronfeld therefore named his good natured double-seater ‘Professor’, ‘Fasold'. This amused Groenhoff a lot, but not Lippisch. By using this name, Kronfeld acknowledged that the ‘Fafnir’, with Groenhoff, would beat his new glider, the ‘Wien’. Kronfeld was later to use a much larger glider built by Kupper, which he called ‘Austria’, after the name of his native country, declaring that “Austria is much larger than its city Vienna (Wien)”