| Fafnir 2 | |
|---|---|
 | |
| Role | High performanceglider Type of aircraft |
| National origin | Germany |
| Manufacturer | Rhön-Rossitten Gesellschaft (RRG) |
| Designer | Alexander Lippisch |
| First flight | c. July 1934 |
| Number built | 1 |
TheRRG Fafnir 2 São Paulo, named after the legendary dragon and theBrazilian city which partially financed it, was a single seatGerman high performanceglider designed byAlexander Lippisch. It set a new world distance record in 1934 and won the 1937International Gliding Championships.
Lippisch began the design of the Fafnir 2 in 1934. Apart from being a wood and fabric aircraft with a strongly taperedcantilevergull wing, it had little in common with theFafnir of 1930, though lessons had been learned from that design. During 1934 the RRG was disbanded and its technical section, led by Lippisch, moved from the Wasserkuppe toDarmstadt to become the DFS, so the new glider was sometimes known as theDFS Fafnir 2. It was Lippisch's last conventional glider design.[1]
The most immediately obvious difference between the two designs was that the Fafnir 2 was amid-wing aircraft. The original Fafnir had a high wing and initially suffered seriousaerodynamic drag losses at the wing-fuselage junctions. Wind tunnel studies at theUniversity of Göttingen showed that these losses were lower with mid-wing designs. They also suggested that the wing and fuselage be integrated and the latter becambered to provide some lift. The strongly tapered wing wasply covered ahead of the singlespar, forming a torsion resisting D-box, andfabric covered aft over most of the span, though the surface near the fuselage was wholly ply covered. The wing section, designed by Lippisch himself, was much thinner and less cambered than on the Fafnir, with less low speedlift but also less high speeddrag, reflecting the increasing understanding that cross country gliding required speed betweenthermals as well as the ability to climb within them. As on the original Fafnir, only the inner 40% of the span haddihedral. Taperedailerons, theirchord increasing outwards, occupied all thetrailing edge of the outer panels.[1]
The Fafnir 2's fuselage was carefully streamlined with a ply skin and had an underlying oval cross section, but the requirement to produce a camber form which blended into the wing made the detailed shaping complex and time-consuming to build. Close to the root, the wing-fuselage extended well ahead and further behind the wing. The tail was conventional, with fabric-covered control surfaces. Thefin was ply-covered and more substantial than on the earlier Fafnir, reaching to the top of therudder, which was straighter-edged and with a sturdier heel. Anall-moving taperedelevator with an unsweptleading edge and a trailing edge notch for rudder movement was mounted on the fuselage mid-line.[1]
The Fafnir 2 landed on a long skid, running from the nose almost to the wing trailing edge. A drop-offdolly was sometimes used for take-off. When first built itscockpit, ahead of the wing leading edge, had a stepped, multi-framed glazedcanopy though by 1937 this had been reworked to blend smoothly into the forward fuselage line.[1]
The Fafnir 2 took part in the July 1934 Rhön competition on theWasserkuppe, from where it set a new world distance record on 27 July of 375 km (233 mi) whenHeini Dittmar flew it toLuban inCzechoslovakia.[1][2] It was the best glider of those at the 1934 Rhön, with a measured glide ratio of 26:1, a good figure for the time but not sufficiently outstanding to invite imitations, given the complexity and expense of the wing/fuselage blending. Nonetheless, even three years later Dittmar flew it to win the 1937 International Championships, held at the Wasserkuppe from 4–17 August and regarded as the firstWorld Gliding Championships.[1][3]
Data from Simons (2006)[1]
General characteristics
Performance