The Glaser-Dirks DG-400 is a single-seat self-launching motorglider that was produced by Glaser-Dirks between 1981 and 1992. It was the first self-launching motorglider with retractable engine and propeller to be produced in large numbers.

This article includes a list of general references, but it lacks sufficient corresponding inline citations. (December 2012)

DG-400
Role	18 metre class sailplane Type of aircraft
National origin	Germany
Manufacturer	Glaser-Dirks
Designer	Wilhelm Dirks
First flight	May 1981
Introduction	1981
Number built	290
Developed from	Glaser-Dirks DG-200

Development

The cost of carbon-fibre had fallen enough in the late 1970s to allow its use in the wing spars of high-performance gliders. Glaser-Dirks introduced a carbon wing variant of the DG-200 about this time. Designer Wilhelm Dirks realised that the span, strength and very low weight of this wing allowed for a self-launching engine to be carried in the glider without an unacceptable penalty when soaring in weak conditions. The DG-400 was created as a result. It first flew in May 1981.

The DG-400 uses the wings and most systems of the DG-202. It has a modified fuselage with a slightly enlarged tailcone and carbon fibre reinforcements to accommodate the engine, which is a relatively large unit with electric starter and electric retraction. This powerful installation, with a user-friendly engine control unit, made the DG-400 easier to operate than other self-launching gliders.

As was typical for the time, the engine, propeller and supporting pylon constitute a single unit that extends into the airflow (in more recent self-launchers the engine usually stays inside the fuselage). The type may be flown either with 15 metre or 17 metre wingtips.

The DG-400 was not aimed at competitions, but rather at leisure flying. Nevertheless, several World Gliding Records have been achieved flying this type.

Specifications (17 metre wings)

Data from [1]

General characteristics

• Crew: 1
• Length: 7 m (23 ft 0 in)
• Wingspan: 17 m (55 ft 9 in)
• Height: 1.4 m (4 ft 7 in)
• Wing area: 10.57 m² (113.8 sq ft)
• Aspect ratio: 27.3
• Airfoil: root:Wortmann FX-67-K-170-17; tip Wortmann FX-60-K-126
• Empty weight: 305 kg (672 lb)
• Max takeoff weight: 460 kg (1,014 lb)
• Fuel capacity: 20 l (5.3 US gal; 4.4 imp gal)

50 l (13 US gal; 11 imp gal) with optional tanks in lieu of water ballast

• Water ballast: 90 l (24 US gal; 20 imp gal)
• Powerplant: 1 × Rotax 505 two-stroke retractable pylon mounted air-cooled piston engine, 32 kW (43 hp)
• Propellers: 2-bladed Hoffman fixed pitch propeller, 1.29 m (4 ft 3 in) diameter

Performance

• Cruise speed: 130 km/h (81 mph, 70 kn) economical

140 km/h (76 kn; 87 mph) max

• Stall speed: 63 km/h (39 mph, 34 kn)
• Never exceed speed: 270 km/h (170 mph, 150 kn) in smooth air

190 km/h (100 kn; 120 mph) in rough air

190 km/h (100 kn; 120 mph) on aero-tow

130 km/h (70 kn; 81 mph) on winch launch

• Range: 400 km (250 mi, 220 nmi) level flight

750 km (400 nmi; 470 mi) cruise/soar

• Service ceiling: 5,000 m (16,000 ft)
• g limits: +6 -4
• Maximum glide ratio: 45 at 110 km/h (59 kn; 68 mph)
• Rate of climb: 3.90 m/s (768 ft/min) at 80 km/h (43 kn; 50 mph)
• Rate of sink: 0.5 m/s (98 ft/min)
• Wing loading: 43.5 kg/m² (8.9 lb/sq ft)
• Power/mass: 0.0714 kW/kg (0.0433 hp/lb)

References

External links

Wikimedia Commons has media related to Glaser-Dirks DG-400.

• DG-Flugzeugbau website
• Sailplane Directory
• DG400 pictures & details
• German Gliding Magazine

На других языках

[de] Glaser-Dirks DG-400

[fr] Glaser-Dirks DG-400