Schleicher K7 Rhonadler / K7 Rhonadler
This tandem two-seater training and club sailplane was designed by Rudolf Kaiser to succeed the wooden two-seater Ka 2 and Ka 2B which had proved to be popular trainers in Germany and had been Kaiser's first design for the Alexander Schleicher firm which he had joined in 1952.
Of conventional wood and fabric construction, with a steel tube fuselage which had fabric covering over wooden formers, the Ka 7 is characterised by high cantilever wings with a forward sweep of 6° 36' at the quarterchord line and 4° dihedral. The single-spar wings are of pine and plywood with fabric covering and a plywood-covered leading edge torsion box; there are Schempp-Hirth air brakes above and below the wings and the wooden ailerons are fabric-covered. The cantilever tail unit is of similar construction to the wings, and there is a trim tab in the starboard elevator. Landing gear consists of a non-retractable and unsprung Dunlop monowheel and a nose skid forward of it carried on rubber blocks for shock absorbtion; there is also a tailskid. The two pilots sit under a Plexiglas canopy the front portion of which hinges to starboard and the rear portion hinges rearwards.
The Ka 7 first flew in prototype form in 1959 and was intended to provide not only basic training but continuation training without a break for pilots graduating to the more advanced high performance sailplanes. In this it was successful and a total of 370 had been built by the spring of 1964.
Ka 7s twice set new German distance records and the type also set a new German goal flight record for two-seaters over a decade after it first appeared. It once held the multi-place world record for speed around a 500 km Triangle at 84 kph/ 45 kt/ 52 mph, set in South Africa in 1964.
A modified plan exists to lower the wings to the mid position and fit a one piece canopy, which makes the modified glider (Ka-7/ 13) look very similar to its successor, the Schleicher Ka-13. The lowering of the wings greatly improves the visibility from the rear seat.
Schneider also built a few Ka 7 two-seaters under licence.
No. Built: 550
Kaiser K 7 Rhonadler
Length: 23.622 ft / 7.2 m
Wingspan: 57.087 ft / 17.4 m
Max take off weight: 1058.4 lb / 480.0 kg
Max. speed: 92 kt / 170 km/h
Schleicher K7 Rhonadler
Wing span: 16m / 52.5ft
Wing area: 17.56sq.m / 188.4sqft
Length: 26ft 7in
Empty weight: 617 lb
Max weight: 1,058 lb
Wing Load: 480kg / 1056lb
Max speed: 124 mph (in smooth air)
Max aero-tow speed: 81 mph
L/DMax: 26 at 80 kph / 43 kt / 50 mph
MinSink: 0.70 m/s / 2.3 fps / 1.36 kt at 43.5mph
Water Ballast: 27.34kg/sq.m / 5.6lb/sq.ft
Aspect ratio: 14.6
Airfoil: Go 533, 16/14%
Kaiser K 7 Rhonadler