The P.Z.L. P.48 Lampart (Leopard) was a more advanced version of the P.38 Wilk multi-purpose ground attack and escort fighter, but the prototypes hadn’t been completed when the Germans invaded Poland in September 1939.
The P.Z.L. P.38 Wilk had begun life as a very ambitious design for an aircraft that could replace the single seat P.Z.L. P.11 fighter and also act as a long range escort fighter, dive bomber and ground attack aircraft. It was essentially a scaled down version of the P.37 Los medium bomber, and was a twin engined low winged monoplane, which was designed to carry a mix of cannon and machine guns in the nose as well as bombs under the fuselage. Its role was effectively the same as the later fighter-bombers, although it soon became clear that it wouldn’t have been a good replacement for the single seat fighter, and by the end of 1936 that part of the plan had been cancelled.
The P.38 was to have been powered by the Polish designed Foka engine. This was a small 8-cylinder inline engine that was being designed by Stanislaw Nowkunski, and was based on an earlier design for a 250-300hp four cylinder engine that had never actually been built. Tragically Nowkunski was killed in a climbing accident in the summer of 1936, before the new engine had begun its bench tests. When they did begin late in the year the engine only produce 400hp, instead of the 600hp it had been designed for, and was too unreliable to use in flight.
By late in 1936 it was thus clear that the Foka engine wasn’t going to live up to expectations, at least not in the immediate future and work began on finding an alternative for the P.38. The American Ranger inline engine was considered, but a more promising alternative was the new Gnome-Rhone 14M Mars double-row radial, which had a similar small frontal area, and was expected to produce 700hp. While the Ranger and eventually the Foka II were used in the two prototypes of the P.38, the main focus of the project moved onto the Gnome-Rhone powered variant, which was designated at the P.48 Lampart (Leopard).
The detailed design of the P.48 was completed early in 1938. However at this point the Polish Aviation Command hadn’t entirely given up on the Foka, as work was proceeding on the Foka II. As a result the decision on what to do with the P.48 was delayed until the end of the year. In the autumn of 1938 that engine produced 420hp on the test bench, and 620hp in take-off mode. Early in 1939 two of these engines were installed in the first P.38 prototype and used in flight trials. However by this point the decision had been made not to put it into production, and the focus switched to the Gnome-Rhone powered P.48.
The P.48 was modified in a number of other ways. The wing looked similar, but had modified flaps, no leading edge slots and carried self sealing fuel tanks. The fuselage was modified to allow it to carry more guns – two 20mm Wz 38 cannon and four 7.7mm KM Wz 36 machine guns in the Lampart A or eight 7.7mm machine guns in the Lampart B, and the pilots cockpit was modified to improve visibility. The P.48 was expected to reach 347.9mph.
At the end of 1938 work began on two P.48 prototypes and a structural test airframe. The first 50 Mars 5 radial engines were expected to arrive in September 1939 and work was underway on the licence built version. By September 1939 the fuselage and wings of the P.48/I were almost complete, and it was expected to be ready for its maiden flight by the end of 1939. However the entire project ended with the German invasion, when both of the incomplete prototypes were probably captured by the Germans.
Work also began on a further version of the design, the P.54 Rys (Lynx). This would have been powered by 1,200-1,600hp Hispano-Suiza 12Y and 12Z upright-vee inline engines and was expected to reach 397mph. However work on this project was at a very early stage when the Germans invaded in September 1939.
Engine: Two Gnome-Rhone 14M05 Mars 5 fourteen-cylinder double-row radial engines
Power: 660-730hp each
Span: 37ft 9in
Length: 28ft 6.5in
Height: 8ft 2.75in
Loaded Weight: 7,716lb (estimated)
Maximum Speed: 347.9mph at 11,482ft (estimated)
Range: 932 miles (estimated)
Guns: Two 20mm cannon and four 7.7mm machine guns or eight 7.7mm machine guns