The DG-100 Standard Class single-seater is a modified and lighter weight developement of the Akaflieg Darmstadt D-38 glass-reinforced plastic sailplane, which first flew in February 1973. The Akaflieg Darmstadt D-38 was designed by Wilhelm Dirks before forming Glaser-Dirks Flugzeugbau GmbH.
The DG-100 has Schemmpp-Hirth type top-surface airbrakes, an all-flying T-tail and water ballast. Options offered included both retractable and fixed landing gear, and a fixed stabilizer. It displayed better performance and handling qualities than expected and so its designer, Dipl-lng Wilhelm Dirks, sought the necessary backing to develop a production version. With Gerhard Glaser he founded the Glaser-Dirks Flugzeugbau GmbH and the DG-100, design of which had begun in August 1973, first flew in prototype form on 10 May 1974.
The DG-100 itself is basically very similar to the D-38 but with a lighter plastic foam supporting the glassfibre skin instead of the balsa wood used in the D-38, and the letter's rounded nose has been replaced by a more pointed nose of better aerodynamic shape. The DG-100 Club version for club flying is available with either an all-moving tailplane or conventional tailplane like the DG-100G's and a fixed monowheel. The DG-100G, first flown on 11 June 1976, is generally similar to the DG-100 except that its tailplane and elevators are similar to those of the later DG-200. The cantilever shoulder wings each have a glassfibre roving main spar and are of glassfibre/Conticell/foam sandwich construction, as are the ailerons and the tailplane. Instead of flaps, there are Schempp-Hirth duralumin air brakes oin the upper wing surfaces; these are considered to be cheaper to make and lighter than flaps, as well as being simpler to operate for landing. Up to 220lb of water ballast can be carried in two wing tanks, and this can be jettisoned in flight. The semi-monocoque fuselage is an all glassfibre structure, as are the fin and rudder.
The prototype DG-100 had an all moving tailplane with a large anti-servo tab, and production aircraft have a similar tailplane with a full-span trimmable anti-Flettner tab. The manually-retractable monowheel has a drum brake, and there is a tailwheel. The pilot sits in a semi-reclining position under a two-piece cockpit canopy, the rear section of which is hinged to open upwards and backwards, the adjustable headrest being attached to the canopy hinge.
Production of the DG-100 series was transferred to the Yugoslav firm Elan, who have been building the DG-100 under licence since the autumn of 1978. A total of 102 DG-100s had been delivered by the beginning of 1978, plus a further 15 examples of the DG-100G.
After more than 100 were built it was succeeded by the DG-101, offering a front-hinged canopy, automatic trim and a cockpit of improved impact-resistant design. The DG-100 Club is an unballasted, fixed gear version with a gross weight of 385 kg / 849 lb.
Production versions were the DG-101, DG-101G and DG-101G Club, which have the forward opening one-piece canopy of the DG-202.
Wing span: 15m / 49 ft 2.5 in
Wing area: 11 sq.m / 118.4s q.ft
Length: 22 ft 11.25 in
Height: 4 ft 7 in
Empty Weight: 230 kg / 507 lb
Payload: 188kg / 415lb
Gross Weight: 418 kg / 922 lb
Wing Load: 38kg/sq.m
Water Ballast: 100kg / 220lb
Airfoil: Wortmann FX-61-184/60-126
Aspect ratio: 20.5
MinSink: 0.58 m/s / 1.94 fps / 1.13 kt @ 40kt / 46 mph
No. of Seats: 1
L/DMax: 36 @ 91 kph / 49 kt / 56 mph
Max speed: 140 kts 161 mph (smooth air)
Stall speed: 32 kts
Max aero-tow speed: 102.5 mph
Glide ratio: 39-1 @ 57 kts / 65mph