PZL P.23 Karaś / P.42 / P.43 Karaś
In response to the Polish Air Force's need to replace its ageing biplane Potez 25 and Potez 27 light bomber/reconnaissance aircraft, a specification was presented to PZL in 1931 (Panstwowe Zaklady Lotnicze - the State Aviation Works) calling for an all-metal light bomber plane powered by a Bristol Pegasus air-cooled radial engine, which should carry a minimum 600 kg (1330 lb) bomb-load, and whose maximum speed should reach 300 km/h (186 mph). Another requirement was the ability to operate from improvised airfields.
During 1931 P.Z.L. had designed a six-passenger single-engine light transport, the P.Z.L. P.13, for service with LOT, but as it had no appeal to the airline its development was abandoned. It was decided subsequently to use this aircraft as the basis for an army co-operation aircraft accommodating a crew of three, and using as powerplant a licence-built version of the Bristol Pegasus radial engine.
Necessary changes to the project, apart from fuselage redesign, included the addition of wing flaps, and the provision for weapons mountings. The wing was designed by Franciszek Misztal, based on his original stressed-skin main spar concept, which had earlier been only tested on the PZL 19 high-performance touring airplane.
The first PZL P.23 prototype
Following evaluation of the design by the Department of Aeronautics, P.Z.L. was instructed to build three prototypes and the first was powered by a 440kW Bristol Pegasus IIM2. Serious problems with the wing's construction caused delays, and the first prototype, powered by the Bristol Pegasus II M2 engine made its maiden flight in August 1934. This aircraft had the designation P.23/I and name Karas (crucian carp), but testing soon revealed a number of shortcomings. The first prototype revealed many problems, which were overcome by the second and third prototypes. The fuselage was redesigned, with internal bomb bay removed to provide more space for the crew, and engine installation lowered for better visibility. The wing's mechanization was redesigned with automatic slats added on the leading edge, and the wing root fairings significantly enlarged.
The P.23/II crashed during flight trials, but the P.23/III performed well and during development flying was modified progressively to what was to be production standard.
After additional changes to the engine fairing and the exhaust, the airplane was accepted by the Lotnictwo Wojskowe and given the designation PZL P.23A Karas.In 1935 production orders were placed for 40 examples of the P.23 Karas A with the 433kW P.Z.L.-built Pegasus II, and 210 of the P.23 Karas B with the 507kW P.Z.L.-built Pegasus VIII. The first P.23A Karas A flew in June 1936, but development problems with the Pegasus II engine resulted in these aircraft being relegated to the training role. The production started in the end of 1935 but its pace suffered because of frequent problems with the Pegasus II M2 engines, license-built by the Polish Skoda works (this engine variant was never produced by Bristol). In addition, the leading-edge slats proved unreliable, and were consequently removed. Only 40 P.23As were built and assigned to training duties, pending the availability of the P.23B variant fitted with the more powerful Bristol Pegasus VIII engine, whose production commenced in the summer of 1936. In February 1937 the production reached the pace of 20 aircraft per month, and the original order for 200 P.23s was fulfilled in September 1937. However, the P.23B Karas B began to enter service in mid-1937 and when production ended the type equipped 14 first-line squadrons. Additional 50 aircraft were ordered, and the production of the P.23B variant concluded in February 1938.
One Karas B was modified under the designation P.42 to serve as a development aircraft for the improved P.46 Sum, with a twin fin/rudder tail unit and a retractable ventral gondola. However, the P.46 did not materialise beyond the prototype stage and the P.42 was subsequently converted back to Karas B standard.
The standard Polish light bomber and reconnaissance aircraft, the PZL.23 Karaś could not be exported because of licence restrictions on the use of the Polish-built (PZL) Bristol Pegasus engine. Developed under the leadership of Henryk Malinowski, the PZL.43 was an improved export variant of the PZL.23, powered instead by a Gnome-Rhône 14K engine, first flying in February 1937.
Like its P.23, the PZL.43 was conventional in layout, a low-wing, all-metal, metal-covered cantilever monoplane. Its fuselage was semi-monocoque. It had a crew of three: pilot, bombardier and an observer/rear gunner. The pilot and observer's cockpits were in tandem and glazed with the open rear gunner's position behind. The bombardier occupied a ventral combat gondola which had a machine gun position at the rear. The fixed undercarriage was heavily spatted, though not suited for rough airfields. Tanks in the centre section of the wings held 740 litres of fuel. A three-bladed propeller was used.
PZL P.43 Karaś
The differences between the two types derived chiefly from use of the heavier and longer (two rows of seven cylinders) Gnome-Rhône engine. To maintain the centre of gravity the fuselage was lengthened by adding one central section which moved the bombardier's gondola rearwards. The new engine improved performance considerably, for example increasing maximum speed from 319 km/h to 365 km/h. In addition, armament was increased with two forward firing Karabin maszynowy wz. 36 machine guns mounted in offset fairings to clear the radial engine. Up to 700 kg of bombs could be carried under the wings, like the PZL.23. A common option was 24 x 12.5 kg bombs (300 kg in total). A camera was fitted.A P-23B was used for testing metallic three-bladed Hamilton Standard propeller.
No prototype preceded the production series of 12 aircraft completed in 1937. These were designated PZL.43A and powered by Gnome-Rhône 14Kirs motors of 900 to 930 hp (671 to 694 kW). An order was placed in April 1936, with the additional requirement of a more powerful Gnome-Rhone 14N-01 engine and an additional forward-firing machine gun, and 12 were built for the Bulgarian air force, given the designation PZL 43A, and delivered in 1937, reforming their airforce after a period of post-World War I treaty constraints.The Bulgarian Airforce called it the Chaika (Чайка, gull).Because of delays in engine shipments from France, this first series was eventually fitted with Gnome-Rhone 14kfs engines.
This model differed by having the 694kW Gnome-Rhone radial engine, improved crew accommodation, and armament increased by the addition of a second forward-firing machine-gun. The excellent performance of the P.43A Karas led to a repeat order in March 1938, totalling 42, for a further improved P.43B Karas with the 950 to 1,020 hp (708 to 761 kW) Gnome-Rhone 14N.1. Of this total 33 were despatched and delivered by August 1939; of the balance, eight had been packed for despatch and the ninth was in final assembly.
Three complete aircraft from the Bulgarian order were left at Okęcie and these were damaged during an air raid on 4 September and later captured by the Germans in a factory in Warszawa-Okęcie. Some damaged aircraft left at Okęcie airfield were captured by the Germans. Five were repaired and delivered to Bulgaria. Another was tested by the Germans in Rechlin in 1940 before joining the others in Bulgaria in October.
Along with 12 PZL.43s and two PZL.43As delivered by Germany in 1940, these gave Bulgaria a total of 50 aircraft. They initially served in three 12-aircraft squadrons of the 1st Line Group (linyen orlyak). From 1942 they were used in the 1st Reconnaissance Regiment and 2nd Line Regiment. Chaikas were used mostly for training and searching for partisans in Macedonia in 1943–44. Several of them crashed during service and there were difficulties in obtaining spare parts. In 1944 they were withdrawn from combat service and were eventually written off in 1946.
At the time of the German invasion of Poland, nine PLZ.43As of the Bulgarian order were crated ready for delivery or were incomplete, two lacking propellors. Five survived the initial German bombing attacks on the P.Z.L. factory and were moved to the airfield at Bielany and taken over by the Polish Air Force for use by 41 Eskadra Rozpoznawcza (41st Reconnaissance Squadron) which was mostly equipped with PZL.23 Karaś. They undertook reconnaissance duties but by 10 September 1939, there were the only two aircraft remaining. One was shot down by a Messerschmitt Bf 110 at Michałówek near Sulejówek and the crew killed. The second, damaged by a pair of Messerschmitt Bf 109s, two days later, crash landed in Brześć.
During the September campaign 114 P.23s were flown by first-line units, and additional 11 (including the five PZL 43s) were received as replacements. Of these, only 17 reached Romania on September 17.
Sometimes the aircraft is called the "PZL P.43", but despite an abbreviation P.43 painted on the tail fin, the letter "P" was generally reserved for fighters of Pulawski's design (like the PZL P.11).
First production series, 12 built.
Second production series with more powerful Gnome-Rhône 14N-01 engine, 42 built.
Improved version, powered by a 980 hp (731 kW) Gnome-Rhône 14N-01 engine.
Bulgarian Air Force operated 50 aircraft
2. jato/ Obrazcow Orliak (2. Squadron of the Exemplary Wing) operated 12 PZL.43
1. Lineen Orliak (Level-flight (bomber) Squadron) operated 36 PZL.43A, 12 in each jato (Squadron)
1. Razuznawatelen Polk (Reconnaissance Regiment) operated PZL.43A between March 1942 and August 1944
2. Lineen Polk (Level-flight (bomber) Regiment) operated PZL.43A between March 1942 and August 1944
113. jato za blisko razuznavanye (Close Distance Reconnaissance Squadron) operated 13 PZL.43A between August 1944 and early 1945
123. jato za blisko razuznavanye operated 11 PZL.43A between August 1944 and early 1945
Luftwaffe tested captured aircraft.
Polish Air Force
41 Eskadra Rozpoznawcza (Reconnaissance Squadron) operated five PZL.43A aircraft
Engine: 1 × Gnome-Rhône 14N-01, 1020 hp (750 kW)
Wingspan: 13.95 m (45 ft 9 in)
Wing area: 26.8 m² (288 ft²)
Length: 9.95 m (32 ft 8 in)
Height: 3.3 m (10 ft 10 in)
Empty weight: 2,200 kg (4,850 lb)
Loaded weight: 3,100 kg (6,830 lb)
Useful load: 900-1,325 kg (1,980-2,920 lb)
Max. takeoff weight: 3,525 kg (7,770 lb)
Maximum speed: 365 km/h at 4,000 m (227 mph at 13,000 ft)
Cruise speed: 300 km/h at ground level (186 mph at ground level)
Stall speed: 115 km/h (72 mph)
Range: 1,250 km (780 mi)
Service ceiling: 8,500 m (28,000 ft)
Rate of climb: 7.5 m/s (1,480 ft/min)
Wing loading: 115 kg/m² (23.7 lb/ft2)
2 x 7.92 mm PWU wz.36B fixed in nose;
1 x 7.92 mm PWU wz.36R in rear upper station;
1 x 7.92 mm PWU wz.36R in underbelly station;
Bombload: 600-700 kg
Engine: Gnome-Rhone 14N-01, 980 hp
Wingspan: 13.95 m
Wing area: 26.80 sq.m
Length: 9.95 m
Height: 3.30 m
Maximum take-off weight: 3525 kg
Empty weight: 2200 kg
Normal takeoff eight: 3100 kg
Maximum speed S/L: 298 kph
Maximum speed at altitude: 365 kph
Cruising speed: 300 kph
Practical range: 1250 km
ROC: 450 m / min
Service ceiling: 8500 m
Armament: one 7.9-mm front gun and two 7.7-mm Vickers machine gun in rear dorsal and ventral positions
Bomb load external: 700 kg
PZL P-23 / P-43 Karas