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 ( ; ; german: link=no, Königshütte ; szl, Chorzōw) is a city in the Silesia region of southern Poland, near Katowice. Chorzów is one of the central cities of the Upper Silesian Metropolitan Union – a metropolis with a population ...

, 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 configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

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 planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

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

longeron In engineering, a longeron and stringer is the 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 ...

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 The Haacke HFM-2 was a German two cylinder flat engine built in the early 1920s. Variants From Flight * HFM-2 () * HFM-2a (); as HFM-2 apart from bore Applications * Albatros L.66 * Dietrich-Gobiet DP.VII * Działowski D.K.D.1 * Dobi-I ...

, 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, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

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 stabiliser, is a small 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 and gyroplane ...

, 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. Fin ...

. 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 takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

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 The Silesia S-4 was a Polish, low-power parasol wing aircraft built in 1925. After an engine change and airframe modifications it became one of the Silesian Aeroclubs fleet. It was lost in a take-off accident in 1931 and was the last Silesia airc ...

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