PZL P.7

From Wikipedia, the free encyclopedia

PZL P.7
PZL P.7
Type	Fighter
Manufacturer	PZL
Designed by	Zygmunt Pulawski
Maiden flight	October 1930
Introduced	1933
Primary users	Poland See Operators
Developed from	PZL P.6
Variants	PZL P.11

The PZL P.7 was the Polish fighter aircraft, designed in early-1930s in the PZL factory in Warsaw. Adopted by the Polish Air Force in 1933 as its basic fighter, in early 1930s, it was one of the first all-metal fighters to be mass-produced with state-of-the-art construction. By the end of the decade however the aircraft were already obsolete and their operational use was coming to an end. Replaced in Polish service by its' modernized version, the PZL P.11c, some P.7s remained in service until 1939 and several dozen planes took part in the Polish Defensive War, scoring at least three kills.

Contents 1 Design and development 1.1 Technical description 2 Operational history 3 Operators 4 Specifications (PZL P.7) 5 Reference

[edit] Design and development

The history of PZL P.7 started in 1928, when a talented designer, Zygmunt Puławski designed an all-metal metal-covered monoplane fighter PZL P.1. It introduced a high gull wing, giving a pilot an optimal view. P.1 was powered with an inline engine, and was flown on 25 September 1929. It developed a speed of 302 km/h, but remained a prototype, because it was decided in Poland, that a fighter should be powered with a licence produced radial engine. Therefore, the next model PZL P.6, flown in August 1930, was powered with the Bristol Jupiter VI FH radial engine. Both aircraft met with a huge interest in the world. Their wing design was called the "Polish wing" or "Pulawski wing". During a presentation at the Paris airshow in Le Bourget in December 1931, a military press recognized P.6 as one of the world's top fighters. Then, the prototype P.6 won the American National Air Races in August-September 1931.

The PZL P.6 did not enter production, because the next improved variant PZL P.7 was developed. The first prototype was basically the P.6 with a stronger engine Bristol Jupiter VII F. Thanks to a charger, it showed better performance on higher altitudes. The prototype was first flown in October 1930. After some changes, most noticeably adding a wide Townend ring to the engine and making a tail slimer, the second prototype was accepted for a production with a designation P.7a.

The first series P.7a were built in a mid-1932, the whole series of 149 (plus one prototype) was completed in 1933. The Polish Air Force received P.7a in 1933.

After designing P.7, Puławski started to develop his design with stronger engines, and the result was PZL P.11, built in a series. Puławski personally was an inline-engine fan, and he developed also a new fighter P.8, with a slim silhouette, powered with an inline engine and reaching a speed of 350 km/h. A planned serial variant was to be designated P.9. Unfortunately, in March 1931 he died in an air crash, and the work upon fighters with inline engines was canceled in a favour of P.11 with a radial engine. The P.11 became the standard Polish fighter. In parallel with P.11, also a development of an export variant PZL P.24 started in 1932.

PZL P.7a entered service in the Polish Air Force in early 1933, replacing PWS-A (licence Avia BH-33) and PWS-10 fighters. Hence the Polish airforce became the first airforce equipped with all-metal fighters only. When the P.7 entered service, they were modern fighters, comparable or better than other contemporary designs, but due to a quick progress in an aircraft technology, they became totally obsolete by 1939. From 1935, in most combat units they were replaced with PZL P.11, which were only slightly more modern. The P.7a were then moved to air schools.

[edit] Technical description

The aircraft was conventional in layout, with high wings, all-metal, metal-covered. The pilot's cab was open. A fuel tank in a hull could be dropped in case of emergency. The armament was two 7.92 mm machine guns on hull sides (initially 7.7 mm Vickers E, then re-bored to 7.92 mm). The plane had the Bristol Jupiter VII F radial engine (normal power: 480 hp (360 kW), maximum: 520 hp (390 kW). An undercarriage was fixed.

[edit] Operational history

At the outbreak of the World War II, on 1 September 1939, the Polish Air Force still had 30 PZL P.7a aircraft in combat units. A further 40 were in air schools, 35 in reserve or repairs - a total of 106 aircraft available. The P.7a were used in three escadres, each with 10 aircraft. The 123rd Escadre was in the Pursuit Brigade, deployed around Warsaw, the 151st and the 162nd Escadres were assigned to Armies. Despite being obsolete, they took part in the Invasion of Poland. Apart from combat units, several P.7a fighters were used in units improvised at air bases.

Almost all the German planes were faster than the P.7a. Furthermore, the Polish planes and their engines were worn out from intensive service use. On the other hand, the P.7 had better maneouvreability, and could operate from short fields (150 m to start), even rough ones. Their armament was insufficient - only two Vickers machine guns, which had a tendency to jam. For these reasons, the pilots flying the P.7a shot down only about seven German aircraft (two He 111, two Do 17, one Hs 126 and two Me 110), suffering losses of 22 aircraft. An improvised task force of P.7a aircraft from units at air bases was rather to confuse and disturb the German bomb raids with their aggressive presence, than to shoot down bombers.

Most of P.7a fighters were destroyed in 1939, some dozen were withdrawn to Romania, but not used in combat. Some captured aircraft were used by the Germans and the Soviets for training.

[edit] Operators

•  Germany: Luftwaffe (captured)
•  Poland
•  Romania

[edit] Specifications (PZL P.7)

General characteristics

• Crew: 1
• Capacity: fighter
• Length: 6.98 m (22 ft 11 in)
• Wingspan: 10.57 m (34 ft 8 in)
• Height: 2.69 m (8 ft 10 in)
• Wing area: 17.9 m² (193 ft²)
• Empty weight: 1,090 kg (2,400 lb)
• Loaded weight: 1,476 kg (3,254 lb)
• Powerplant: 1× Bristol Jupiter , 520 hp (388 kW)

Performance

• Maximum speed: 327 km/h (203 mph)
• Range: 600 km (370 mi)
• Service ceiling: 8,500 m (27,900 ft)
• Rate of climb: 62.4 m/min (204.72 ft/min)

Armament

• 2 x 7.9 mm machine guns

[edit] Reference

• Kopanski, Tomasz J. PZL P.7: CZ.2. Gdansk, Poland: AJ Press, 2001. ISBN 83-7237-081-8.

Related content
Related development	PZL P.11, PZL P.24
Similar aircraft	Dewoitine D.371 - Loire 46 - Ikarus IK-2 - Polikarpov I-15
Designation series	PZL.5 - PZL.6 - PZL P.7 - PZL P.8 - PZL P.11 - PZL.12
Related lists	List of fighter aircraft