Monday, May 11, 2015

Greek PZL P.24

The Greek Air Force first bought five P.24As in 1937, then 25 P.24Fs and six P.24Gs in 1938.

The PZL P.24 is the best known Polish built fighter aircraft of the pre-WW2 period. It was the ultimate achievement in Zygmunt Puawski’s gull-winged fighter family including prototypes P.1, P.6, P.8, and mass-produced P.7a, P.11a and P.11c.

Although it was used by countries such as Turkey, Bulgaria, Romania and Greece, it was never used by Polish Air Force. The armament, speed and other flight characteristics were much better than characteristics of P.11c, which was the main fighter of Polish Air Force in September 1939. This situation was so unbelievable that even in the German aircraft recognition manual Flugzeugerkennungs-Tafeln from 1939, P.24 was listed as a main Polish fighter plane! However, P.24 was only offered for export and was built under license in Turkey and Romania.

In 1932 director Weiller of the French company Gnôme-Rhône proposed PZL (Polish Aircraft Factory) to equip P.11 with Gnôme-Rhône engine and put this aircraft into a contest for a new fighter for Armee de l’Air. This project was given to Wsiewood Jakimiuk, who was in charge of P.7/P.11 development after Zygmunt Puawski’s death in 1931. The prototype was built using the wings, rear fuselage, horizontal tailplanes, rudder and undercarriage from PZL P.7, which was just being introduced into production. The heavier engine required a longer fuselage (additional 45 cm between the cockpit and wings) and a new engine mount. The cockpit was enclosed, but the prototype had an open cockpit. Two 20 mm cannons were chosen as the new aircraft’s armament.

Several modifications from P.11 prototypes were also used. Gnôme-Rhône supplied a 14-cylinder Gnôme-Rhône 14Kds Mistral Major radial engine. The first prototype P.24/I was completed in January 1933 and flown by Captain Bolesaw Orliñski in May 1933. During the first flight the aircraft lost its propeller due to engine vibrations. The pilot landed safely, however, the engine had to be sent back to France for repairs. The tests ended in February 1934 and in March the second prototype P.24/II was flown by captain Orliñski.

P24/II was initially equipped with a 14Kds Mistral Major engine, which was later replaced by Gnôme-Rhône 14 Kfs offering more power (661 kW instead of 515 kW). Also a new three-bladed propeller was installed. The prototype was designated P.24 Super and first flown in June 1934. On 28 June 1934 captain Orliñski established a world speed record of 414 km/h (recognised by FAI) for fighter aircrafts with radial engines. Later, during summer, the P.24/II was equipped with two Vickers 7.9 mm machine guns and two Oerlikon FF 20 mm cannons and was shown on International Airshow in Paris in November 1934. At the time it was one of the most advanced fighter aircraft and one of the first to be equipped with cannon. However, P.24 could not be even put into a contest for a new French fighter because of the protests from French aircraft industry. Despite this set-back several other countries displayed interest in a new Polish construction and in 1936 P.24/II was shown to military representatives of Bulgaria, Estonia, Turkey, Greece, Yugoslavia and Romania.

In 1935 Hungary wanted to buy a licence for P.24, but Polish government declined the offer due to military restrictions applied to Hungary after WWI. Also in 1935 a new Polish fighter P.11c was introduced into production and PZL decided to build the third prototype of P.24 based on P.11c. The P.24/III or P.24bis Super was a hybrid of P.11c (rear fuselage, wings, horizontal tailplanes and rudder) and P.24/II - engine and cannons. This version also had an enclosed cockpit (P.24/I and P.24/II had an open cockpit). The P.24/III was advertised in two versions:

P.24A with 2 x 20 mm Oerlikon FF cannons and 2 x 7.9 mm Colt-Browning MG40 machine guns and P.24B with 4 x 7.9 mm Colt-Browning MG40 machine guns. Both versions could carry 4 bombs under the wings (10 kg or 12.5 kg).
The following versions were built:
P.24A - 14 aircraft were bought by Turkey and additional 20 built under license, 2 x 20 mm Oerlikon FF cannons and 2 x 7.9 mm Colt-Browning MG40 machine guns, 4 x 12.5 kg bombs under wings, Gnô me-Rhô ne 14 Kfs engine and three-bladed Letov propeller.
P.24B - 12 aircraft ordered by Bulgaria, 4 x 7.9 mm Colt-Browning MG40 machine guns, 4 x 12.5 kg bombs under wings, Gnô me-Rhô ne 14 Kfs engine and three-bladed Letov propeller.
P.24C - 26 aircraft made for Turkey; identical with B, but had two racks for 50 kg bombs under wings
P.24E - Romania ordered 6 aircraft of this version from Poland and built 40 under license in IAR Brasov factory. P.24E was equipped with 661 kW Gnô me-Rhô ne 14 KIIc32 engine (built in Romania under licence) and two-bladed Szomañ ski wooden propeller, 4 x 7.9 mm Colt-Browning MG40 machine guns. Later on a new 691 kW IAR 14 KIIIc36 engine was used.
P.24F - 30 machines ordered by Greece; 2 x 20 mm Oerlikon FF cannons and 2 x 7.9 mm Colt-Browning MG40 machine guns, 4 x 12.5 kg or 2 x 50 kg bombs under wings, 700 kW Gnô me-Rhô ne 14N-07 engine.
P.24G - 6 aircraft ordered by Greece, as P.24F, but with 4 x 7.9 mm Colt-Browning MG40 machine guns.
The total of 157 aircraft (including three prototypes) were built in Poland and additional 60 under licence in Romania (40) and Turkey (20).

General characteristics
    Crew: 1
    Capacity: fighter
    Length: 7.81 m (25 ft 7 in)
    Wingspan: 10.68 m (35 ft 1 in)
    Height: 2.7 m (8 ft 19 in)
    Wing area: 17.90 m² (192.7 ft²)
    Empty weight: 1,330 kg (2,930 lb)
    Loaded weight: 1,915 kg (4,220 lb)
    Max takeoff weight: 2,000 kg (4,400 lb)
    Powerplant: 1× 14-cylinder double row radial engines: P.24A, B, C: Gnome-Rhône 14Kfs, P.24E: Gnome-Rhône 14K IIc32, P.24F, G: Gnome-Rhône 14N07, P.24A, B, C: 900 hp / 930 hp (max) (Gnome-Rhône 14Kfs), P.24E: 900 hp / 930 hp (max)(Gnome-Rhône 14K IIc32), P.24F, G: 950 hp / 970 hp (max) (Gnome-Rhône 14N07) (P.24A, B, C: 671 kW / 693 kW (max) (Gnome-Rhône 14Kfs), P.24E: 671 kW / 693 kW (max) (Gnome-Rhône 14K IIc32), P.24F, G: 709 kW / 723 kW (max) (Gnome-Rhône 14N07))
    Maximum speed: 430 km/h (270 mph)
    Range: 550 km (340 mi)
    Service ceiling: 10,500 m (34,449 ft)
    Rate of climb: 11.5 m/s (2,260 ft/min)
    Power/mass: 0.376 kW/kg (0.230 hp/lb)
    2 Oerlikon FF cannons and 2 MGs (P.24A, P.24E and P.24F),
    4 MGs (P.24B, P.24C and P.24G),
    4 x 12.5 kg (4 x 28 lb) bombs (P.24A and B),
    2 x 50 kg (2 x 110 lb) bombs (P.24C, F and G).

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