Glaser-Dirks DG-300

The DG-300 has a flapless wing with triple taper based on the Falcon designed by Hansjörg Streifeneder, and employs the HQ 21/II, a relatively thick profile (ca. 17.5%). This wing is 'blown' on the underside by 900 small holes to achieve a controlled transition from laminar to turbulent flow without additional drag. However, these holes are prone to clogging due to dirt, moisture and wing surface polishing, which makes them less effective over time. As with any racing glider, the thickness of the wing makes it relatively sensitive to performance degradation due to contamination by insect impacts or rain drops.

It is agile and a good climber, but slightly underperforms compared to its competitors in cruising flight, especially at higher speeds. The later DG-303 version with a new wing profile and winglets was developed that delivers higher performance at low to medium speeds plus increased aileron response. A fully aerobatic version (the Acro) was also sold, stressed for +7/-5g.

The DG-300 has typical DG features, which improve comfort and safety if at a performance cost. It has the large cockpit typical of DG giving excellent comfort, especially in high-altitude flight where the full-length canopy allows the feet to be warmed by sunlight. The view from the cockpit is superb, adding to the pleasure and safety of flight.

After the bankruptcy of Glaser-Dirks the newly founded DG Flugzeugbau GmbH took over the servicing of these gliders.

The operational limits were changed on April 2007 after a defect was detected on the main spar which affects unknown number of gliders. Aerobatic flight since then is not permitted, even for the Acro versions unless the spar is inspected for defect and repaired.

DG-300 Elan

Initial production version

DG-300 Club Elan

With fixed undercarriage for club use

DG-300 Elan Acro

Fully aerobatic (restricted from aerobatic flight after 2007,unless you let DG do a resurge of the wing)

DG-303 Elan

With a new aerofoil section and optional winglets; available in standard, club and acro versions, built by the Slovenian company AMS-Flight until end of 2006

General characteristics

• Crew: One
• Capacity: 130 kg (287 lb) water ballast
• Length: 6.80 m (22 ft 8 in)
• Wingspan: 15.00 m (49 ft 2 in)
• Height: 1.39 m (4 ft 6 in)
• Wing area: 10.3 m² (110.5 sq ft)
• Aspect ratio: 21.9
• Airfoil: Horst & Quast HQ21/II
• Empty weight: 238 kg (525 lb)
• Gross weight: 500 kg (1,102 lb)

Performance

• Maximum speed: 270 km/h (167 mph, 145 kn)
• Maximum glide ratio: 42
• Rate of sink: 0.59 m/s (115 ft/min)

Aircraft of comparable role, configuration, and era

• Schleicher ASW 19
• Schempp-Hirth Discus
• Rolladen-Schneider LS4

Related lists

• List of gliders

Wikimedia Commons has media related to DG-300.

• DG Flugzeugbau website
• AMS-Flight
• Richard Johnson, A FTE of the DG-300, Soaring, August 1985
• Sailplane Directory
• Main spar defect discussion
• Technical Note 359-24