Kraków 2015-02-03
Polish Aviation Industry.
Part 8
Państwowe Zakłady Lotnicze PZL in Warsaw.
History of Okęcie.
On January 22, 1925, at the request of the City Council, the City Council of Warsaw decided to buy the areas of Okęcie, Paluch and Służewiec for a modern airport and sports facilities. In 1933, the construction of a new military airport and airport for air communication began at Okęcie. The Mokotów airport was not suitable for expansion due to the proximity of residential houses.
The airport was designated with an area of 285 ha, in the shape similar to an ellipse, 2 100 m long and 1 570 m wide. The take-off field received an area of about 200 ha. In addition, the area was allocated to hangars, barracks, workshops, housing estates for officers and technical services. The buildings were designed by captains Czeżewski and Wielawski. Communication with Śródmieście was provided by a wide street, which to commemorate two tragically deceased pilots was called Żwirki i Wigury street. The Warsaw – Okęcie Airport was officially opened on September 28, 1934. More at Okęcie Airports in the Airports section.
Państwowe Zakłady Lotnicze – PZL.
At the end of the 20 years, the authorities of the Republic of Poland realized that they had no influence over the structure of the Polish Aviation Industry. This entire department was in the hands of private companies. Only Centralny Zakłady Lotnicze belonged entirely to the state. This situation has good and bad points. The problem is that the first experiences of Polish governments with companies were disturbing and ended with corruption and the scandal. An example was the Francopol company. Therefore, the field of aviation, which was to produce aircraft for the needs of the Polish Army, it was decided to have total control. That is, to have her as a state.
On March 15, 1928, an airframe manufacturing plant was established as an independent state-owned enterprise, based on Centralne Zakłady Lotnicze. The company’s location did not change and was still located in the Mokotów Airport area.
The company director was still Ing. Witold Rumbowicz, who performed this function from February 1, 1927 to February 8, 1935. The head of the design office, which at the time was called the Technical Office, was Ing. Stefan Malinowski.
It was a time when the strength of Polish Military Aviation was still based on foreign aircraft built under license.
It is worth noting here that the beginnings of Polish Aviation were definitely more difficult than in other European countries. Mainly because the production of aircraft at that time was based on the automotive industry. Who made cars made it easier to build planes. First of all, he had mastered modern technologies. Secondly, he used serial production organization. Thirdly, he produced engines for cars, which at the time were not much different from aircraft, so he had a drive. The partitioners in the territory of the Republic of Poland did not build a single car or engine factory. These were the main reasons that led to the fact that initially in Poland all aircraft constructions were wooden. Joinery in Poland, we had mastered to perfection. And by the way; the largest flying boat in the world was made of wood; Hughes H-4 Hercules, a span of 97.54 m, length 66.65 m, height 24.18 m. In 1928, the world was already moving towards metal aircraft, or at least mixed constructions. Also, the Polish State Factory was to go towards metal constructions. In order for the PZL plant to become acquainted with foreign achievements in this field, a license was bought for the French Wibault 7 fighter aircraft, designed by the outstanding engineer Macel Wibault. The technology of riveting individual elements of the panels was particularly interesting. The plane had a sheath made of dur-aluminum sheet metal of varying thickness; 0.32 mm, 0.4 mm and 0.5 mm. In addition, the sheet was finely grooved; 1.6 crèches per cm. Such coverage was light, stiff and caused less aerodynamic drag than the corrugated sheet used at Junkers. 25 copies of Wibault 7 aircraft were built at PZL, which were later called Wibault 70. The plant gained experience in the production of metal aircraft, and riveting structures had a major impact on most of PZL’s subsequent aircraft structures in the 30-year period. Being ahead of the facts, it should be noted that Polish Military Aviation has become the first in the world equipped exclusively with metal combat aircraft.
The technical and development base for the production of airplanes at PZL was the Institute of Aviation Technical Research and the Aerodynamic Institute of the Warsaw University of Technology, led by Professor Czesław Witoszyński, called the Father of Polish Aviation. The Institute of Aviation Technical Research was opened in 1927. Bartel BM-4 planes were produced in Wielkopolska Wytwórnia Planów – "Airplane" and used in the Polish Army. The company survived a great fire in 1928, and declared bankruptcy in 1930. Therefore, one of the first works of PZL was the modernization of Bartel BM-4a planes, equipping it with another engine and giving the designation BM-4f. Similarly was done with the construction Bartel BM-5a, giving it the designation BM-5d. PZL after Centralne Zakłady Lotnicze inherited the continuation of production of wooden wooden Fighter planes Spad S-61. A few more were built under the PZL brand, but the production was completed very soon, because the plane was dangerous and several pilots were killed.
First constructions PZL.
However, the main plans of the Polish Government for PZL were different. The goal was to design, build, fly, test and implement aircraft for serial production; hunting, liaison, bomber, passenger and school-sport. Five project teams were organized to deal with the following projects:
PZL P-1 – pursuit plane, i.e. a fighter plane built under the direction of Zygmunt Puławski. The first flight took place in September 1929, and gave rise to the whole family of fighters.
PZL Ł-2 – liaison, built under the direction of Jerzy Dąbrowski and Franciszek Kott. The prototype was flown at the end of 1929, and 30 (25) units were built. It was the second construction of PZL plants built serially. Because the Lublin R-XIII aircraft turned out to be better, the production of PZL Ł-2 was suspended. On the PZL Ł-2 SP-AFA aircraft in rally execution, pilot captain Stanisław Skarżyński and engineer Andrzej Markiewicz in 1931, they made a flight around Africa, 25 050 km long.
PZL-3 – a bomber, powered by four engines, designed under the direction of Władysław Zalewski. The program has not been implemented.
PZL-4 – passenger, powered by three engines, designed under the direction of Zygmunt Bruner and Stanisław Prauss.
PZL-5 – school and sport, under the direction of Stanisław Malinowski and Władysław Kozłowski. The first flight of the prototype took place in 1930, and in 1930-1931, 15 (10) units were built. PZL-5 was the first PZL factory production produced in series. In 1932, the aircraft was modernized and the PZL-5 bis was created, which lost the competition to RWD-8.
The family of Zygmunt Puławski’s fighter aircraft.
The talented engineer Zygmunt Puławski, at only 27 years old, designed the PZL P-1 fighter aircraft. In its development, the designer used technologies used in the production of the Wibault 7 aircraft; external riveting and finely grooved sheet metal. But he also applied his own ideas. The first was the mewi lobe, called the Polish patch abroad. In addition to good aerodynamics, the flap provided good visibility for the pilot forward and sideways. The second solution was a scissor type chassis. These solutions are found in P.6, P.7, P.8, P.11, P.24. They made Puławski’s name famous in the world, and in some countries they were used in those constructions; France (Mureaux 170/180, Loire 43/46, Dewoitine 560, Arsenal-Delanne 10), Czechoslovakia (Aero A-102), Yugoslavia (Ikarus IK-1 / IK-2), USA (Douglas 0-31), Germanic (Dornier Do-C1, Henschel Hs-121).
In August 1929, the PZL P.1 prototype was ready. An in-line engine was used for the drive. The aircraft proved to be correct, although it required several corrections.
The problem was the in-line engine, however. During this time two views clashed. Some believed that the future were star engines; less weight, better cooling, easier to use, cheaper to buy. Others thought the future was in-line engines; smaller frontal surface, water cooling option. Because we were not engine manufacturers, that’s why Polish doctrine was based on radial engines, the licenses of which were purchased and the use of in-line engines was not anticipated.
That is why Eng. Zygmunt Puławski adapted the PZL P.1 aircraft for propulsion with a star engine. More structures driven by this type of engine were created; P.6, P.7, P.8, P.9, P.10, P.11. Although the designer did not completely abandon the construction with government engines. Such was initially PZL P.8, whose prototypes were built and flown in 1931, and again in 1932. It was similar with the PZL P.10 construction.
The adaptation of the PZL P.1 aircraft to the star engine resulted in the need to rebuild the entire fuselage that received a circular cross-section. And here there was another change; the designer designed a half-shell system. It was a significant innovation. It was in 1930, that the first half-shell airframes appeared in the world. The first were; American Northrop, French Dewoitine and Nieuport and Polish PZL P.6, because this designation was given to the new Zygmunt Puławski aircraft, as it was the next construction of the PZL plant, after PZL-5.
The PZL P.6 prototype was flown in August 1930 and was shown at the International Air Show in Paris at the end of this year. Its characteristic flap and semi-shell structure were immediately appreciated. When Captain Bolesław Orliński demonstrated the fighter in the air, the world press recognized PZL P.6 as the best fighter aircraft. It was written that it is ahead of all other constructions built on the European continent. In 1931, Captain Bolesław Orliński won the competition of the best pilots in the world in Cleveland, USA. This is how the PZL plant gained a good reputation abroad. A lot was written about Poland well.
PZL P.7 is a P.6 serine variety that was flown in October 1930. In the period 1932-1933, 150 fighters were produced, which were designated PZL P.7a. They replaced all previously used fighter planes in the Polish Army. In 1933, Poland became the first country in the world with fighter aviation equipped exclusively with metal planes. The great career of engineer Zygmunt Puławski was interrupted by his death. He died on March 21, 1931, while flying on a prototype of his amphibian PZL-12.
Still in 1930, eng. Zygmunt Puławski developed an improved version of PZL P.6, which received a more powerful engine. After the death of the designer, his gun ran the PZL design office. Nobody dared to attach to the amazing constructions of Zygmunt Pulaski. His gun was still under the direction of Vsevolod Yakimuk. The fighter with the new engine received the designation PZL P.11. Serial production started, which lasted in the period 1933-1936.
PZL P.11a – 30 machines for the Polish Army. PZL P.11b – 50 machines for Romania. PZL P.11c – 175 machines for the Polish Army. With lowered engine and modified vertical tail. PZL P.11f – is a variation of PZL P.11c, 80 machines built under license in Romania, at the IAR plant. PZL P.11g Kobuz – due to delays in PZL P.50 Jastrząb tests, it was decided to develop a Kobuz aircraft with an engine that was already manufactured and was intended for Jastrzębie. Production was to begin in the autumn of 1939 at the Podlasie Aircraft Factory. After building the PZL P.11c, the world became even more interested in planes from Poland and wanted to buy them. For our aircraft to compete on foreign markets, they had to be among the fastest. For this purpose, even more powerful engines had to be used. The Bristol engine, manufactured under license from us, already had less power than newer designs, and the license agreement forbade us to export these engines. So there was a need to look for an engine with a power of up to 736 kW (1,000 HP). The choice fell on the French Gnome-Rhone 14K engine, which was then easy to buy. The airframe was rebuilt for this power unit and in March or May 1933, the aircraft was flown as PZL P.24. He developed a speed of 414 km / h and was the fastest starfighter fighter of the time. We managed to win several orders and started serial production, which lasted in the period 1936-1939. She bought fighters; Turkey, Greece, Romania. These aircraft were also built under license in Turkey and Romania. PZL P.24 has established a good reputation about the Polish Aviation Industry. In Poland, PZL P.1-P.24 fighters built 510 machines and another 170 abroad.
Constructions Państwowych Zakładów Lotniczych.
The first period – fighters (pursuit planes).
Wibault 70 – later also called PZL Wibault 7 in Poland. French fighter aircraft built in Poland under license. The first flight in France on July 7, 1925. The Wibault 7C1 aircraft was presented at the Paris Air Show in 1927. The aircraft attracted the interest of the Polish delegation led by General Ludomił Rayski. In 1928, a license was purchased. The first Wibault 70C1 aircraft produced under license was built in April 1929. Wibault 70C1 aircraft produced in Poland in 1930 were directed to the fighter squadrons of the 1st and 2nd Air Regiment, where until the end of 1931 they were used as fighter aircraft, and then they were directed to training squadrons. In air regiments they were replaced by PZL P.7 aircraft. In 1933, they were withdrawn from air regiments and transferred to the Aviation Training Center in Dęblin, where they were used until 1935.
PZL P.1 – 1929, pursuit plane, i.e. a fighter built under the direction of Zygmunt Puławski. High-wing aircraft with in-line engine. The first flight took place in September 1929, and gave rise to the whole family of fighters.
PZL P.2 – 1930, fighter aircraft design based on PZL P.1. Work on the project was discontinued because the structural solutions proved to be inappropriate (Brackets without stiffening tapes).
PZL P.6 – 1930. It is often stated that it was based on PZL P.1. In fact, the engine was changed from row to star and the fuselage was completely rebuilt. A prototype was built. The first flight was made in August 1930.
PZL P.7 – 1930, fighter based on PZL P.6, produced in series.
Bartel BM-4f – 1931, school aircraft.
Bartel BM-5d – 1931, school aircraft.
PZL P.8 – 1931, construction fighter Eng. Zygmunt Puławski. An attempt to return to fighters with a government engine. PZL P.8 / I prototype, which was flown in 1931. The second PZL P.8 / II prototype with a more powerful engine was flown in 1932, shown at the International Air Show in Paris. Death of Eng. Zygmunt Puławski finally stopped his efforts to obtain government engines for PZL. Priority is given to the construction of PZL P.11. Hispano-Suiza 12Mc (640 hp) or Lorraine-Dietrich 12H (675 hp) in-line engine cooled with liquid.
PZL P.9 – 1931 year, unrealized project.
PZL P.10 – 1931, unrealized project Zygmunt Puławski. Developed on the basis of PZL P.8 with a more powerful Rolls-Royce "Kestrel" engine with 750 hp.
PZL P.11 – 1931, fighter, design by eng. Zygmunt Puławski, the work was completed under the guidance of Vsevolod Yakimuk. Serial production started, which lasted in the period 1933-1936.
PZL P.24 – development of PZL P.11, with a more powerful engine. Built for export (1936-1939) and licensed abroad.
Written by Karol Placha Hetman