The PZL-37A / B Łoś is a Polish, two-engine low-wing bomber with a full metal structure, with a retractable landing gear. The flight of the prototype took place in December 1936, and serial production continued in 1937-1939. The PZL-37 was the most modern Polish military aircraft built before World War II and the world's first serial aircraft with a laminar wing profile. As a result, it developed a speed in excess of 400 km / h. The plane was among the world's top bombers at the end of the 1930s. By September 1939, 96 Elks had been built, 9 of which were crushed. 40 fought in the Bomb Brigade, while 37 were in the training squadron and in the Aviation Cadet School, and 5 in trials and 5 in repairs. The elk of the Bomb Brigade was fought by the German armored units near Radomsko, Pułtusk and Różan. 23 Łosie were evacuated to Romania, 2 landed in the USSR, 2 were captured by the Germans, and 60 were destroyed. The Romanian air force commandeered Łosie. Romanian characters and numbers from 201 to 220 were painted on them. They were used by Romania, which fought on the side of Germany with the Soviet Union, among others for the bombing of Odessa. Technical data (version B): length: 12.92 m, wingspan: 17.93 m, height: 4.25 m, maximum speed: 412 km / h, practical ceiling: 9250 m, maximum range: 1500 km, armament: fixed - 3 machine guns wz.37 7.92mm caliber, suspended - up to 2580 kg of bombs.The PZL P.11a (the so-called eleven) is a Polish, single-engine fighter plane with a metal structure with Puławski wings, a classic tail and a fixed landing gear. The flight of the prototype took place in 1931, but serial production continued in 1937-1939. The first serial version is the PZL P.11a powered by the Bristol Mercury IV S2 engine with a power of 550 HP. However, it was treated as a transitional version and only 50 were ordered. The most famous version of the "eleven" - PZL P.11c - appeared in the summer. It had an improved fuselage, wings and a vertical stabilizer. It all improved the aerodynamics of the plane. The drive unit has not changed. The interest in the construction was expressed by, among others, Romania, where 95 units of the licensed PZL P.11 were manufactured at the IAR plants. At the outbreak of the war, all versions of the P.11 were much slower than their German opponents, but at the same time had greater maneuverability, high rate of climb and a less emergency engine than German planes. They had many victories over the enemy during the September campaign, mainly as part of the Pursuit Brigade. Technical data (version P.11c): length: 7.55m, wingspan: 10.72m, height: 2.85m, maximum speed: 367km / h, rate of climb: 14.5m / s, maximum ceiling: 8000m, range maximum: 550 km, armament: fixed - 2 machine guns wz.33 cal.7.92 mm.