The CSS-11 is an aircraft very similar to the CSS-10 aircraft. Work on both structures was carried out in parallel. The CSS-11 aircraft was built under the direction of engineer Leszek Dulęba. In April 1947, Leszek Dulęba was appointed as the Airframe Team Manager. Two prototypes of the CSS-11 aircraft were built in the CSS workshops.
The CSS-11 aircraft is a two-seater low-wing monoplane of mixed construction. The fuselage is made of steel tube, the wings are of wooden structure.
Simple wings with a wooden structure. NACA 23012 profile. They had one spar, covered with plywood from the front. The back part of the wing is covered with fabric. Slotted ailerons, differentially deflected, with a wooden frame, covered with fabric. The wing has no flaps.
Open cabins, second cabin located above. Truss hull, welded from steel pipes. The hull in the cabins is covered with duralumin sheet, in the rear part with fabric on profiled slats.
Trapezoidal tail with rounded ends. Double-girder fins, nose caisson covered with plywood, the rest with canvas. Rudders with a wooden frame, covered with canvas.
Fixed landing gear with tail wheel.
Walter “Minor 6-III” in-line engine with a take-off power of 125 hp (92 kW). The engine is carbureted. Two-bladed wooden propeller.
On 18 October 1948, the first prototype made its first flight. The pilot was J. Szymankiewicz. Both aircraft were handed over to GIL for tests.
The CSS-11 aircraft proved successful. It had good flight characteristics. The results were better than expected. The plane performed aerobatic manoeuvres correctly and easily exited the spin. The assessment of the aircraft said that the CSS-11 aircraft is suitable for training and aerobatics.
Just like CSS-10, it was planned to launch serial production of CSS-11 aircraft. Production was to be 30 machines. The lack of engines stood in the way. License production of Walter engines in Poland has not been started. In the period 1952-1953, for political reasons, both prototypes were cancelled.
Engine: Walter Minor 6-III, 125 hp (92 kW)
Span: 10.60 m / 34 ft 8 in
Wing area: 16.50 sq/m / 168 sq.ft
Length: 7.50 m / 24 ft 8 in
Height: 1.83m / 7 ft
Empty weight: 575 kg
Take-off weight: 850 kg / 2070 lb
Payload: 200 kg
Fuel capacity: 90 lt
Top speed: 208 km/h / 140 mph
Cruising speed: 175 km/h / 105 mph
Landing speed: 75 km/h
ROC: 4.2 m/s
Ceiling: 5,950 m
Range: 660 km / 680 mi
Landing run: 160m
TO run: 120 m
All Aero 