The PZL.23 Karaś was the Polish light bomber and reconnaissance aircraft, designed in the mid-1930s in the PZL factory in Warsaw. It was the main light bomber in the Polish September Campaign.

Development

The first prototype flew in summer of 1934, designed by Stanislaw Prauss. In the third prototype, a pilot's seat was raised and the engine was lowered to obtain better view. This prototype was accepted for a production, with a name Karaś (in Polish - the crucian carp). The first series, PZL.23A was fitted with a radial engine Bristol Pegasus IIM2 670 hp (500 kW) produced in Poland under licence. Since this engine showed not fully reliable, the final variant PZL.23B was fitted with a newer Pegasus VIII 720 hp (537 kW).

In 1936, there were produced 40 of PZL.23A. Because of engine faults, their service ceiling was limited and they were next moved to air schools. Between 1936 and 1938 there were produced 210 of PZL.23B. They became a main armament of Polish bomber and reconnaissance escadres, in the 1930's called "line escadres", replacing Breguet 19 and Potez 25.

For export purposes, there was developed variant PZL.43 with a stronger engine Gnome-Rhone. It had better characteristics, than PZL.23 (maximum speed - 365 km/h), and the pilot had 2 machineguns shooting forward, instead of 1. Bulgaria bought 12 PZL.43 with engine Gnome-Rhone 14Kirs 900 to 930 hp (671 to 694 kW). Then, Bulgaria ordered 42 PZL.43A with engine Gnome-Rhone 14N01 950 to 1020 hp (708 to 761 kW), but only 36 were delivered before the war. At that time, Poland developed a new light bomber, PZL.46 Sum, but only one prototype was completed before the war, in 1938. There was also an experimental variant of Karaś, PZL.42, with double tail fin and modified bombardier gondola, hiding into the hull.

Combat use

In 1939, the plane was not a modern one. Its main fault was low speed, its manoeuvreability was not high as well. At the outbreak of the World War II, on September 1, 1939, Poland had 118 PZL.23B in combat units (further 50 PZL.23B and 35 PZL.23A were in air schools or under repairs). PZL.23B were used in 5 bomber escadres of the Bomber Brigade and 7 Army reconnaissance escadres, each with 10 aircraft (other escadres of the Bomber Brigade were equipped with PZL.37 Los). They actively took part in the Polish September Campaign. Some planes were also used in a wartime improvised units.

On September 2, 1939, one PZL.23B of the 21st escadre bombed a factory in Olawa as the first bomb attack on the German territory. The bomber escadres attacked German armoured columns, while the main mission of Army escadres was flying in a reconnaissance. All PZL.23 were suffering big losses due to low speed, lack of armour and fighter protection. Many were shot down by the German fighter planes, but they also shot down a few. Some 20 aircraft crashed on rough field airfields. The 5 escadres of the Bomber Brigade delivered about 52-60 tons of bombs during the campaign, the Army escadres brought about dozen tons of bombs as well. About 90% of PZL.23 were destroyed in 1939. In a campaign, also 2 PZL.43A were used in the 41st Escadre, left from Bulgarian order.

11 PZL.23B and about 20 PZL.23A were withdrawn in 1939 to Romania and then used by the Romanian aiforce against the USSR. 50 PZL.43 and PZL.43A (2 were delivered by the Germans) were used in Bulgaria for training until 1946, with a name "Chaika". None of PZL.23 existed in Poland after the war.

Technical design

The aircraft was conventional in layout, with low wings, all-metal, metal-covered. The crew consisted of three: pilot, bombardier and a rear gunner. A combat station of bombardier was in a gondola underneath a hull, where he also operated an underbelly machinegun. An undercarriage was covered with a significant aerodynamic covers, but despite a massive look, it was not suited best for rough airfields. The bombs were carried under the wings: the maximum load was 700 kg (6 x 100 kg and 2 x 50 kg). The engines used were: Bristol Pegasus IIM2 normal: 570 hp (425 kW), maximum: 670 hp (500 kW) - PZL-23A; Pegasus VIII normal: 650 hp (485 kW), maximum: 720 (537 kW) - PZL-23B; Gnome-Rhone 14N01 normal: 950 hp (708 kW), maximum: 1020 (761 kW) - PZL.43. Sometimes the plane is called "PZL P.23", but despite an abbreviation P.23 painted on a tail fin, the letter "P" was generally reserved for fighters of Pulawski's design (like PZL P.11).