Schleicher ASW 17
Also known as the Super Orchidee, this Open Class high performance single-seater was designed by Dipl-lng Gerhard Waibel as a development of the AS-W 12. It was the second of Waibel’s Open Class designs.
Superseding the ASW-12, it is a shoulder wing monoplane with a 90 metre wingspan which is in four sections, only 4.5 inches deep at the root. It has a fibreglass span skin, while the fuselage is monocoque two-skin glass fibre sandwichof a special plastic hexcell monocoque. It is dominated by the large dorsal fin and rudder, which is over 6 ft high, which is sculptured from a 6 inch diameter fuselage where the empennage (conventional low-set tailplane and elevator) emerges. The mainplanes have full length four-position flap/ ailerons which give a variable wing geometry of from +9 deg to –11 deg.
The modified Wortmann wing section is thicker than the AS-W 12's to enable water ballast to be carried in wing tanks. Built in the wings forward of the spar are rubberised ballast tanks with a capacity of 95 litres / 100 kg / 220 lb. For penetration, this load can be dumped in 1 min 50 secs. The aluminum double segment dive brakes in both the upper and lower surfaces are effective to the extent that the tail parachute used in the prototype is no longer a standard item. The single, retractable sprung mono landing wheel is a large 500 x 15, with considerable ground clearance. The wheel brake is operated by a T-bar alongside the left leg. Cockpit space is ample and lengthy, and a pilot up to 6 ft 6 ins can be accommodated quite easilyin a semi-reclining seat under a flush-fitting one-piece canopy. Controls are conventional. Ventilation is drawn from the fuselage near the trailing edge. Visibility is excellent, comfort good, and all control reaches are very good.
It first flew in prototype form on 17 July 1971 and 52 AS-W 17s had been built by January 1977; production has now ceased.
The AS-W 17 soon made its mark in competition flying, coming second in the Open Class in the 1972 World Championships at Vrsac, Yugoslavia, flown by Mathias Wiitanen of Finland, third in the 1974 World Championships at Waikerie, Australia, flown by Hans-Werner Grosse of Germany, and winning the 1976 World Championships, held in Finland, for Britain flown by George Lee; this was the first British victory since 1952. The AS-W 17 has made some notable long distance flights, inlcuding a world record goal flight of 765.4 miles by Hans-Werner Grosse on 16 April 1974; he also set a triangular distance record of 660.5 miles (1,063km) in Australia in an AS-W 17 on 18 January 1977, this flight also breaking the speed record for a 1,000km triangular closed circuit at 61.2mph. An ASW-17 flown by Hans Werner Grosse of Germany gained the World record 1,000 km speed triangle at 145.33 kph/ 78.5 kt/ 90 mph and the 1,250 speed triangle at 133.24 kph/ 71.9 kt/ 82.8 mph in 1980.
Wing span: 20m / 65 ft 7.5 in
Wing area: 14.86 sq.m / 159.8 sqft
Length: 24 ft 9.25 in
Height: 6 ft 1.25 in
Empty Weight: 404 kg / 890 lb
Payload: 166 kg / 367 lb
Gross Weight: 570 kg / 1257 lb
Max airspeed: 130 kt / 149 mph (in smooth air)
Rough air speed: 130 kt
Stall: 37 kt
L/DMax: 100 kph / 54 kt / 62 mph at 42 kt
MinSink: 0.50 m/s / 1.64 fps / 0.97 kt at 46.5 mph
Best glide ratio: 48.5:1 at 65 mph
Wing Load: 38.36kg/sq.m / 7.8lb/sq.ft
Water ballast: 220 lb
Aspect ratio: 27
Airfoil: Wortmann FX 62-K-131 (mod.)