Akaflieg Braunschweig SB-5 Danzig

The Akaflieg Braunschweig SB-5 is a German single-seat Standard Class sailplane designed and prototyped by students of Brunswick University. More than 100 were built to their design, in several different variants.
Design.
The Akaflieg Braunschweig or Akademische Fliegergruppe Braunschweig () is one of some fourteen German undergraduate student flying groups attached to and supported by their home Technical University. Several have designed and built aircraft, often technically advanced and leading the development of gliders in particular.
The SB-5 is a cantilever shoulder-wing monoplane with a plywood monocoque fuselage which has an outer fibre glass skin, a single spar wooden wing with plywood skinning, and a V-tail. Its wing, with a constant chord centre section and tapered outer panels, has 2.50° of dihedral and Schempp-Hirth airbrakes at 50% chord. The pilot has an enclosed cockpit with a Plexiglass canopy and the landing gear is a non-retractable, unsprung monowheel with a tailskid.
The SB-5 prototype first flew on 3 June 1959. A licence to build it went to Firma Eichelsdörfer at Bamberg, who produced more than 100 including all variants. The first three variants, SB-5a-c detailed below, differed chiefly in their forward fuselages and canopy shapes and the last (SB-5e) by having an extended span
Airworthiness directives.
Luftfahrt-Bundesamt, the national civil aviation authority of Germany, has issued two airworthiness directives concerning the structure of the tail section of this glider. Both related to issues with frame components towards the rear of the fuselage: the first, dated 30 January 1986, required an immediate inspection of frame 25 for cracking; the second, issued on 11 July 1991, required the gluing of frame 26 to be reinforced. The UK Air Accidents Investigation Branch cited these directives in its investigation of an accident in Cumbria, England, on 7 August 2019, when the tail section of a model SB-5e broke away in turbulent air conditions, causing the loss of the aircraft.
Operational history.
In 2010, there were thirty seven SB-5s on the German civil register and one each on the Belgian and UK registers. Of these, eighteen were SB-5bs, twenty SB-5es and one a SB-5c.