RRG Professor

In early 1928 Professor Walter Georgii, an academic meteorologist and head of the Rhön-Rossitten Gesellschaft (RRG), began studies of thermals, previously assumed to be too weak to assist gliders.

The prototype was christened the Rhöngeist (English: Ghost of the Rhön Mountains) after Lippisch, who had earned this nickname during earlier visits to the Wasserkuppe gliding centre.

[1] This was an all wood-framed aircraft, covered in a mixture of plywood and fabric, with a braced, three piece wing supported over the fuselage on a tall ply skinned, streamlined pedestal and built around a single spar.

Its rectangular centre section occupied about one third of the overall span and was braced to the lower fuselage on each side with a faired V-form lift strut.

The Professor II, first flown in 1929, addressed some of these problems by increasing the mean overall wing chord with fuller, curved ailerons, modifications first applied to the prototype Rhöngeist.

The Professor II also had new horizontal tail with a fixed, swept tailplane mounting constant chord, rounded tip elevators with a cut-out for rudder movement.