The PWS-35 ''Ogar'' ( en,

Polish Hound The Polish Hound, commonly known as Ogar Polski, is a breed of hunting dog indigenous to Poland. The Polish Hound has a keen sense of smell. This heightened sense combined with the endurance needed to hunt in harsh environments led to its use i ...

) was a two-seat,

aerobatic Aerobatics is the practice of flying maneuvers involving aircraft attitudes that are not used in conventional passenger-carrying flights. The term is a portmanteau of "aerial" and "acrobatics". Aerobatics are performed in aeroplanes and glid ...

training Training is teaching, or developing in oneself or others, any skills and knowledge or Physical fitness, fitness that relate to specific practicality, useful Competence (human resources), competencies. Training has specific goals of improving on ...

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

that was designed by Kazimierz Nowicki, Marian Piątka and Michał Rosnowski at the

Lviv Polytechnic Lviv Polytechnic National University ( ua, Націона́льний університе́т «Льві́вська політе́хніка») is the largest scientific university in Lviv, Ukraine. Since its foundation in 1816, it has bee ...

in 1935/1936.

Design and development

The aircraft was designed by three young scientists at the Lvov University of Technology ("Polytechnic") as their thesis. The designers initially planned to build a single aircraft (designated as the NPR-1, after the initials of the design team's members), but in 1937 the

Podlaska Wytwórnia Samolotów Podlaska Wytwórnia Samolotów (PWS) - ''Podlasie Aircraft Factory'' - was a Polish aerospace manufacturer between 1923 and 1939, located in Biała Podlaska. History Podlaska Wytwórnia Samolotów SA was created in 1923. The first aircraft prod ...

became interested in their design and hired professional designers to modify it to fit the needs of the Polish Air Force. At the time the PAF was looking for an advanced trainer and it was decided that Ogar would be perfect for that role. The prototype was completed in 1937 and in early 1938 underwent static tests. In the summer of 1938 it was successfully test-flown by S. Szubka. The first prototype, equipped with a

de Havilland Gipsy Major The de Havilland Gipsy Major or Gipsy IIIA is a four-cylinder, air-cooled, inverted inline engine used in a variety of light aircraft produced in the 1930s, including the famous Tiger Moth biplane. Many Gipsy Major engines still power vintag ...

engine, was heavier than anticipated and as a result the aircraft had poor stall characteristics and stability issues. By the end of the summer a second prototype, with an enlarged vertical stabilizer and a stronger PZInż. Major engine was completed and sent to the Institute of Aviation in Warsaw for further tests. Michał Rosnowski designed further modifications and the aircraft was scheduled to enter serial production in late 1938, however, numerous problems with handling and weight and balance postponed the start of serial production until late 1939. Out of the initial order of 150, 50 were finally ordered in the summer of 1939. Out of the first batch of 17 airframes started in July 1939, none were delivered to the Polish Air Force by the

invasion of Poland The invasion of Poland (1 September – 6 October 1939) was a joint attack on the Republic of Poland by Nazi Germany and the Soviet Union which marked the beginning of World War II. The German invasion began on 1 September 1939, one week aft ...

. The first prototype was provided to the air force but was destroyed near

Lubartów Lubartów () is a town in eastern Poland, with 23,000 inhabitants (2004), situated in Lublin Voivodeship. It is the capital of Lubartów County and the Lubartów Commune. Historically it belongs to Lesser Poland. Lubartów was established in 154 ...

shortly afterwards. The other prototype was destroyed in an air raid on Warsaw's

Okęcie Airport Warsaw Chopin Airport ( pl, Lotnisko Chopina w Warszawie, ) is an international airport in the Włochy district of Warsaw, Poland. It is Poland's busiest airport with 18.9 million passengers in 2019, thus handling approximately 40% of t ...

. The aircraft was powered by a four-cylinder PZInż. Major 4 engine, with .

Variants

;PWS-35/I :First prototype. ;PWS-35/II :Second prototype.

Specifications (PWS-35/II)

References

{{PWS aircraft 1930s Polish sport aircraft PWS aircraft Aircraft first flown in 1938 Biplanes