09/30/2024. Remarks by Johan Visschedijk: "Jarosław Janowski of Łódź, ca. 75 mls (120 km) south-west of Warsaw, was a designer and constructor of aircraft and aircraft engines. His second project was the single-seat sport J-2 Polonez (Polonaise), which he designed in 1971. Janowski also built an aerodynamic model of the Polonez that was tested at the Warsaw University of Technology. Janowski produced documentation and detailed drawings, with the help of Andrzej Wiśniewski from the Institute of Aviation, to supply to amateur builders. In all, about 200 copies were sold in Poland and abroad.

The building of the Polonez by a professional carpenter was estimated about 800 hours The first aircraft completed (also referred to as 'prototype') was built by Józef Leniec of Szczecinek, who introduced a number of changes and improvements of his own design.

J-2 Polonez 'prototype' (Johan Visschedijk Collection)

The Polonez 'prototype' was first flown by the builder on August 22, 1977, on October 1, 1984, it was destroyed in a crash, in which Józef Leniec lost his life.

Wings: Cantilever mid-wing monoplane. Wing section NACA 23012. Constant-chord wings. All-wood single-spar structure. Leading-edge plywood-covered, rest of wing fabric-covered. Fabric-covered ailerons. No tabs.
Fuselage: Pod and boom type. Enclosed cabin faired into front fuselage. Wooden single-boom structure supporting tail unit.
Tail unit: Cantilever wooden structure, with T tailplane. Fin plywood-covered; remainder fabric-covered. Sweptback vertical surfaces and constant-chord non-swept horizontal surfaces. Tab in trailing-edge of horizontal surfaces, plus two mass balance arms projecting forward of leading-edge.
Landing gear: Non-retractable single main wheel, with tire size 350-135, and tailwheel.
Power plant: Modified 30 hp Trabant two-cylinder two-stroke air-cooled car engine, mounted at top of fuselage aft of cabin and driving a two-blade fixed-pitch wooden pusher propeller. The aircraft may be fitted with any other suitable engine of 25-40 hp.

Span: 23 ft 0 in (7.00 m)
Length: 15 ft 10.5 in (4.84 m)
Height: 4 ft 5.25 in (1.35 m)
Wing area: 75.35 sq.ft (7.00 sq.m)
Empty weight: 231 lb (105 kg)
Take off weight: 518 lb (235 kg)
Max speed: 99 mph (160 kmh)
Cruise speed: 74.5 mph (120 kmh)
Stall speed: 37.5 mph (60 kmh)
Max climb at sea: 590 ft (180 m)/min
Endurance: 3 h

The aircraft on top of the page was constructed by Andrzej Fiuk, who introduced several modifications to the original design. Amongst them, a slightly longer reinforced fuselage, a larger cabin to improve ergonomics, a taller fin and larger rudder, a steel fuselage truss fitted with a faired two-wheeled landing gear, and a 40 hp Hirth Gobler F23A engine. Hence the modifications the aircraft was designated J-2B Polonez, it is both referred to as the Janowski as well as the Fiuk J-2B Polonez. Intended to be first flown in 1988, it was not until 1992 that the Polonez first flew, the pilot was an engineer named January Roman.

J-2B Polonez (SP-P048) (Johan Visschedijk Collection)

The aircraft was registered SP-P048 in the Special-S2 category, later the second P was deleted. Presently the J-2B is preserved in Krakow.