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DG300

DG300 Elan

Written by Webmaster

Monday, 09 October 2006

DG300 Elan in Horsham DEVELOPMENT and DESCRIPTION

The DG-300 was the successor to the successful DG-100 (standard class) and DG-200 (racing class) gliders designed by Wilhelm Dirks. His first design; the Akaflieg Darmstadt D-38 displayed better performance and handling qualities than expected so Dirks decided to develop a production version (the DG-100). He found the backing for this venture in Gerhard Glaser, founding the Glaser-Dirks Flugzeugbau GmbH in 1973.

The DG-300 is a single place high performance sailplane, with 15 meter wingspan designed for for the FAI Standard Class. Developed for competition purposes it does not replace the highly successful DG100, a successful club aircraft which was still to be produced.

The main different features of the new aircraft are as follows:

A new thinner high performance wing profile section, developed at the DFVLR Braunschweig by Messrs Horstmann and Quarst (HQ), is used. Boundary layer control by blowing ensures an optimal boundary layer for minimum drag. The wing has reduced sensitivity to bugs and rain. This feature results from numerous wind tunnel tests done by Prof. Wortmann and Dr. Althaus at Stuttgart.
The wing planform is a triple trapezoid which is very near the optimum elliptical planform. Together with the new wing tip design, this helps reduce induced drag.
The wing/fuselage junction is faired in accordance with the latest developments to reduce interference drag and increase low speed performance.
The fuselage has been shortened 20 cm.
The rudder chord has been reduced to 44% of the fin chord to reduce rudder forces. A new profile has also been used on the fin to reduce drag.
The air brakes are larger than the DG100, to give even better short field landing ability.
All controls connect automatically.
The maximum all up weight is 80 kg higher than the DG100 with 180 kg water ballast.
The cockpit is 2 cm wider for added comfort.
The canopy frame has been stiffened and canopy sealing further improved.

CONSTRUCTION

Wings:	GFRP-foam-sandwich-skin. GFRP-Rovings.
Elevator:	GFRP-skin
Ailerons, Tailplane and Rudder:	GFRP-foam-sandwich-skin.
Fuselage:	GFRP-skin.
Undercarriage:	Retractable, assisted by a gas strut, spring mounted, internal drum brake, fully sealed landing gear box.
Tyre:	5.00 - 5 (Ø 362 mm) (14.25 in) 4 PR or 6 PR.
Tailwheel:	Tyre 200 x 50 2 PR.
Tow release:	Safety release “Europa G 73” for winch launch and aerotow near the C.G. Additional as option “nose release E 75” installed under the instrument panel only for aerotow.
Cockpit:	In flight adjustable rudder pedals and adjustable seat back for either automatic or manual parachutes, adjustable head rest. Large single piece clear plexiglas canopy, hinged at the nose, supported by a gas strut. Instruments and instrument panel covered by a housing which is held on by 6 screws - easily removable for unhindered access to instruments. Controls for undercarriage and dive brakes are on the left hand side of the cockpit. Parallelogram control column stick for the elevator. This eliminates PIO's in rough air. Release lever for elevator trim on control stick.
Dive Brakes:	Schempp-Hirth dive brakes on the upper wing surface.
Tailplane:	T-Tail with conventional stabiliser-elevator and spring trim.
Water ballast system:	95 litre (25 US gal.) or 65 litre (17 US gal.) water ballast bags in each wing panel. A fin water ballast tank may be provided as an option. (5.5 litre or 1.45 US gal.)

DG300 in Weikerie DG300 in Benalla PERFORMANCE DATA

Span	15.0m
Length	6.8m
Height	0.81m
Wing Area	10.27m²
Aspect Ratio	21.9
Empty Glider Mass	245kg
All-Up Mass	525kg
Water Ballast	190kg
Load Factors	+5.3 -2.65
Maximum L/D	41 at 54kt
Stalling Speed	35kt
Minimum Sinking Speed	0.59m/s
Max. Rough Air Speed	108kt
Never Exceed Speed	146kt