PZL P.24 A-G

Unwilling to abandon his idea of a fighter with an in-line engine, Pulawski designed an experimental model designated the PZL P.8 powered with a 600 hp engine. It was test flown by Orlinski in the summer of 1931 and reached a maximum speed of 330 kph (205 mph). A second prototype, the PZL P.8/II with a 675 hp engine made its first flight in March, 1932, and reach a top speed of 350 kph (217 mph). In July, 1932, Orlinski was to fly the PZL P.8/II to the International Air Meeting in Zürich, but crashed near Konskie, Poland. A few days later he made a second attempt in the PZL P.8/I but crashed near Innsbruck, Austria. In December, 1932, the rebuilt PZL P.8/II was exhibited at the Paris Salon. When in 1935, Yugoslavia showed interest in buying the plane, improvements and a new model, the PZL P.28 were proposed by the factory but the order never came to fruition.

Pulawski's fighter planes with radial engines
At the end of 1929 the Department of Aeronautics in the Ministry of Army Affairs had chosen the Bristol Jupiter radial engine and all subsequent models for its fighter planes. It was well known that radial engines were simpler to construct, lighter, and air-cooled (which further reduced the weight by another 40 kg, or 88 lbs, of water). They were easier and cheaper to use, more resistant to damage from enemy fire (on account of the fact that they did not feature a water cooling system susceptible to small arms fire), and required less fuel. In addition, the radial construction moved the center of gravity much closer to the center of the airplane, which had a positive effect on maneuverability. The main drawback, though, was their large diameter. This had a negative impact on forward visibility and, as a result of the widened fuselage cross section, increased drag considerably. The license agreement with Bristol was valuable in that it gave the Poles rights to build all Bristol engines designed within the next 10 years, but also contained a clause that none of the engines could be built for export. This complicated the sale abroad of Polish designed fighters utilizing these engines.

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In spite of his conviction that in-line engines gave the pilot better visibility, Pulawski was forced to accept the situation as it was. In the fall of 1929 the Polish army had placed an order for Pulawski's plane, but with a radial engine. Pulawski immediately set about designing the new plane, which was called the PZL P.6. The new engine forced him to redesign the fuselage in an "O" shape. The new shape made it possible to use a semi-monocoque design. Changes were made to the wings, control surfaces and undercarriage as well. Basically, the PZL P.6 was a completely new design, which utilized concepts and experience gained during the construction of the PZL P.1. By using an engine that was 175 kg (385 lbs.) lighter and an airframe that was 60 kg (132 lbs.) lighter the PZL P.6 weighed 235 kg (518 lbs.) less than the PZL P.1. During the planning stages there was a proposal to construct two variants of the plane: one with a 450 hp Jupiter VI engine for use at low altitudes and a second with a Jupiter VII which would give the plane a cruising altitude of 4,000 m (13,123 ft.). The low altitude version would keep the P.6 designation, while the high altitude version would get the P.7 designation.
The PZL P.6 prototype was flown by Orlinski in August, 1930. It was easy to handle and achieved a top speed of 292 kph (181 mph) and a climb rate of 10.3 m/sec. (2,028 ft./min.). The P.6 was exhibited at the Paris Salon in December 1930, where it drew attention for its gull wing design and duralumin semi-monocoque construction. On December 22 Orlinski flew an amazing display routine in the P.6 at Le Bourget airfield. It was not long before the international aeronautical press was proclaiming the P.6 the best fighter plane in the world. In August, 1931, Orlinski took part in the National Air Races in Cleveland, Ohio and competed against the best aerobatic pilots in the world with Udet representing Germany, Bernardi – Italy, Atcherly – England, Williams – U.S.A. and Kubita – Czechoslovakia. Orlinski's daring aerobatics brought him personal success and enthused the crowd. The local press wrote that "Orlinski delighted the crowd and won respect for the Polish airplane industry." Without a doubt Orlinski's two appearances brought fame to PZL and Pulawski. The P.6 prototype was destroyed in a crash in October 1931, outside of Olsztyn (Czestochowa), when the propeller and engine fell off. Orlinski was able to parachute to safety. Only one prototype of the PZL P.6 was built and no further work was done on the plane.

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