The Silesia S-3 was the first design from the Polish Sopora brothers to fly. It was a low power, single seat, high wing light aircraft. Only one was built and its flying time was limited.

Design and development

Three brothers, Edward, Paul and Wojciech Sopora set up an aircraft-building workshop in 1923 at

Chorzów Chorzów ( ; ; ) is a city in the Silesia region of southern Poland, near Katowice. Chorzów is one of the central cities of the Metropolis GZM – a metropolis with a population of 2 million. It is located in the Silesian Highlands, on the Rawa ...

, calling it the Pierwsza Śląska Fabryka Samolotów (First Silesian Aircraft Factory). Their first product was a light, low-powered,

high wing A monoplane is a fixed-wing aircraft A fixed-wing aircraft is a heavier-than-air aircraft, such as an airplane, which is capable of flight using aerodynamic lift. Fixed-wing aircraft are distinct from rotary-wing aircraft (in which a r ...

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

, the Silesia S-3. Its wood-framed, thin section wing was in two parts joined to the upper fuselage

longeron In engineering, a longeron or stringer is a load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural fram ...

s and was fabric covered. It was entirely wire-braced from a high, central cabane above the fuselage and a short cabane from its underside. The C-3 was powered by a Haacke HFM-2, a

flat-twin A flat-twin engine is a two-cylinder internal combustion engine with the cylinders on opposite sides of the crankshaft. The most common type of flat-twin engine is the boxer-twin engine, where both pistons move inwards and outwards at the same ti ...

mounted with its cylinders projecting outside the fuselage for cooling. Behind the engine the fuselage was flat-sided, with a steel-tube frame of rectangular section and fabric covering. The single, open

cockpit A cockpit or flight deck is the area, on the front part of an aircraft, spacecraft, or submersible, from which a pilot controls the vehicle. The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls th ...

was behind the upper cabane. Its

empennage The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third ed ...

was wood-framed and fabric covered; the

tailplane A tailplane, also known as a horizontal stabilizer, is a small lift (force), lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters ...

, on top of the fuselage, was wire braced to the top of a rounded

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. F ...

. The rudder was also rounded in profile. Its fixed

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for taxiing, takeoff or landing. For aircraft, it is generally needed for all three of these. It was also formerly called ''alighting gear'' by some manufacturers, s ...

was of the tailskid type. The mainwheels were on a single axle which was mounted on two transverse tubes joining the apexes of two V-struts from the lower fuselage longerons.

Operational history

The S-3 was completed by October 1923 and in early November it made its first flight, piloted by Klosek, from the army field at Panewniki near Ligota. Several modifications followed, in particular addressing some longitudinal stability problems experienced on the first flight. On 16 November Klosek began its official flight trials in front of army observers. It made three flights, each lasting 10–15 minutes, reaching speeds of about , taking off in and with landing runs of . The S-3 continued to make short flights into 1924 but after a landing accident the Soporas decided that its Haake engine should be removed to power their next design, the Silesia S-4 and the S-3 was abandoned.

Specifications

References

{{reflist, refs= {{cite book, title=Polish Aircraft 1893-1939, last=Cynk, first=Jerzy, year=1971, publisher=Putnam Publishing, location=London, isbn=0-370-00085-4, page
592–3
url-access=registration, url=https://archive.org/details/polishaircraft1800cynk/page/592 {{cite web , url=http://www.samolotypolskie.pl/samoloty/2746/86/Silesia-S-32, title=Silesia S-3 , access-date=21 December 2017 Single-engined tractor aircraft 1920s Polish sport aircraft S-03 High-wing aircraft Aircraft first flown in 1923