PZL.23 Karaś

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PZL.23 Karaś -the third prototype PZL.23/III

The PZL.23 Karaś was a Polish light bomber and reconnaissance aircraft, designed in the mid-1930s by PZL in Warsaw. It was the main light bomber in the Invasion of Poland.

1 Development
2 Combat use
3 Technical design
4 Operators
5 Specifications (PZL.23A)
6 Specifications (PZL.23B)
7 References
8 Related content

[edit] 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 Bristol Pegasus IIM2 radial engine of 670 hp (500 kW) produced in Poland under licence. Since this engine proved to be not terribly reliable, the final variant PZL.23B was fitted with a newer Pegasus VIII of 720 hp (537 kW).

PZL.23A (serial number SP-BMF) on display during Paris Air Show during the 1930s

In 1936, forty PZL.23A were produced. Due to engine faults their service ceiling was limited and they were used only in the training role. Between 1936 and 1938 210 PZL.23B were produced with the newer engines. They became a main armament of Polish bomber and reconnaissance squadrons, in the 1930's called "line escadres", replacing Breguet 19 and Potez 25.

The Bristol engines were licensed for use in Poland only, so for export purposes the Gnome-Rhone 14K was used in a variety of PZL designs. In this case the 14K-powered PZL.23 became the PZL.43. The new engine improved the plane's performance considerably, maximum speed increased to 365 km/h even though the armament was increased to two machine guns for the pilot. Bulgaria bought 12 PZL.43's with the 14Kirs of 900 to 930 hp (671 to 694 kW). They ordered a further 42 with the new Gnome-Rhone 14N-01, an improved 14K design that delivered 950 to 1,020 hp (708 to 761 kW), but only 36 were delivered before the war.

At that time, Poland developed a new light bomber, the PZL.46 Sum, but only one prototype was completed before the war, in 1938. There was also an experimental variant of the Karaś, PZL.42, with double tail fin and modified bombardier gondola, hiding into the hull.

PZL.23A on the Warsaw Airport. Note lines of PZL-P.11 or PZL-P.7 fighters in the background.

[edit] 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 squadrons of the Bomber Brigade and 7 Army reconnaissance squadrons, each with 10 aircraft (other squadrons of the Bomber Brigade were equipped with PZL.37 Los). They actively took part in the Invasion of Poland. 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 squadrons attacked German armoured columns, while the main mission of Army squadrons was reconnaissance. All PZL.23 suffered high 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 in return. Some 20 aircraft crashed on rough field airfields. The five squadrons of the Bomber Brigade delivered about 52-60 tons of bombs during the campaign, the Army squadrons added about a dozen tons of bombs as well. About 90% of PZL.23 were destroyed in 1939. In addition two PZL.43A from the Bulgarian order were impressed into Polish service in the 41st Squadron.

11 PZL.23B and about 20 PZL.23A were withdrawn in 1939 to Romania and then used by the Romanian air force 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". No PZL.23's were left in Poland after the war.

[edit] Technical design

PZL.23A of the production series

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. The fixed undercarriage was well spatted, but despite a massive look, it was not suited 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).

[edit] Operators

[edit] Specifications (PZL.23A)

General characteristics

Crew: 3
Capacity: bomber
Length: 9.68 m (31 ft 9 in)
Wingspan: 13.95 m (45 ft 9 in)
Height: 3.3 m (10 ft 10 in)
Wing area: 26.8 m² (288 ft²)
Empty weight: 1,928 kg (4,251 lb)
Loaded weight: 2,813 kg (6,202 lb)
Max takeoff weight: 3,428 kg (7,557 lb)
Powerplant: 1× Bristol Pegasus IIM2 radial engine, 670 hp (500 kW)

Performance

Maximum speed: 304 km/h (189 mph)
Stall speed: 110 km/h (68 mph)
Range: 1,260 km (783 mi)
Service ceiling: 7,300 m (23,950 ft)
Rate of climb: 6.5 m/s (1,280 ft/min)

Armament

3 x machine guns:
- 1 x 7.92 mm fixed in nose;
- 1 x 7.7 mm in rear upper station;
- 1 x 7.7 mm in underbelly station;
700 kg (1,543 lb) bombs.

[edit] Specifications (PZL.23B)

General characteristics

Crew: 3
Capacity: bomber
Length: 9.68 m (31 ft 9 in)
Wingspan: 13.95 m (45 ft 9 in)
Height: 3.3 m (10 ft 10 in)
Wing area: 26.8 m² (288 ft²)
Empty weight: 1,980 kg (4,365 lb)
Loaded weight: 2,893 kg (6,378 lb)
Max takeoff weight: 3,526 kg (7,774 lb)
Powerplant: 1× Pegasus VIII; radial engine, 720 hp (537 kW)

Performance

Maximum speed: 319 km/h (198 mph)
Stall speed: 110 km/h (68 mph)
Range: 1,260 km (783 mi)
Service ceiling: 7,300 m (23,950 ft)
Rate of climb: 6.7 m/s (1,319 ft/min)

Armament

3 x machine guns:
- 1 x 7.92 mm fixed in nose;
- 1 x 7.7 mm in rear upper station;
- 1 x 7.7 mm in underbelly station;
700 kg (1,543 lb) bombs.

[edit] References

Enzo Angelucci & Paolo Matricardi, World War II Airplanes (2 vol.), Rand McNally, 1978.
Mark Axworthy, Third Axis/Fourth Ally: Romanian Armed Forces in the European War 1941-45, Arms & Armor Press, 1995.
Jerzy Cynk, The Polish Air Force at War: The Official History (1 vol), Schiffer Publishing, 1998.
Jerzy Cynk, The P.Z.L. P-23 Karas, Profile Publications, 1966.
Andrzej Glass "Samolot rozpoznawczo - bombardujący PZL - 23 Karaś, Wydawnictwo MON, Warsaw, 1973 (TBIU Series)
Hans Werner Neulen, In the Skies of Europe: Air Forces Allied to the Luftwaffe, 1939-45, Crowood Press, 2000.