PZL P.6

PZL P.6
PZL P.6
General information
Type	Fighter
Manufacturer	PZL
Designer	Zygmunt Puławski
Status	Prototype Destroyed
Primary user	Polish Air Force
Number built	1
History
First flight	August 1930
Developed from	PZL P.1
Variants	PZL P.7

The PZL P.6 was a Polish fighter, designed by the engineer Zygmunt Puławski, manufactured by PZL state-owned factory. It remained a prototype and did not go into production.

Design and development

The history of PZL P.6 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. The P.1 was powered with an inline engine, and developed a speed of 302 km/h, but remained a prototype, because it was decided, that a fighter for the Polish Air Force should be powered with a radial engine, licence produced in Poland. Therefore, the next model PZL P.6, was powered with the Bristol Jupiter VI FH radial engine.

The PZL P.6 was flown for the first time in August 1930 with test pilot Bolesław Orliński at the controls. It had a very similar wing to the P.1, but the fuselage was completely redesigned with a modern semi-monocoque configuration introduced that was oval in cross-section, as well, the tail was also changed. As a result of the modifications, the aircraft was over 200 kg lighter.

Technical description

The PZL P.6 was an all-metal duralumin-covered, braced, high-wing monoplane. The fuselage was framed in a front section and semi-monocoque in mid and tail sections with an oval cross-section. The two-spar wing of trapezoid shape, thinner by the fuselage, covered with a rimmed Wibault type duralumin sheet, was supported by two struts on either side. The pilot's cockpit was open, with a windshield. The Bristol Jupiter VI FH radial engine mounted in front was fitted with a Townend ring and used a two-blade propeller. The fixed undercarriage with a rear skid was mainly conventional and typical of the period. An unusual feature was a fuselage fuel tank that could be dropped in case of a fire emergency.

Testing and evaluation

The P.6, just like the P.1, garnered a great deal of interest worldwide. Their wing design was called the "Polish wing" or "Puławski wing". During a presentation at the Paris Air Show in Le Bourget in December 1931, the aviation press, such as L'Air, The Aeroplane, Flight and Die Luftwacht acknowledged the P.6 as one of the world's top fighter designs. Significantly, the P.6 prototype, piloted by Bolesław Orliński, won the American National Air Races held in Cleveland between the 29th of August and the 7th of September 1931.

The PZL P.6 did not enter production, because at the same time the next improved variant, the PZL P.7 was being developed. The first P.7 prototype retained most design tratis of the P.6 with a more powerful supercharged Bristol Jupiter VII F engine, achieved better performance at higher altitudes.

The sinlg eP.6 prototype crashed on 11 October 1931 near Częstochowa due to a propeller breaking apart, resulting in catastrophic engine failure. The pilot, Orliński, bailed out successfully.

Variants

P.6/I : First prototype, later became P.7 prototype.

Operators

Poland

Polish Air Force

Specifications (P.6/I)

Data from Polish aircraft 1893-1939 ^[1]

General characteristics

Crew: 1
Length: 7.16 m (23 ft 6 in)
Wingspan: 10.3 m (33 ft 10 in)
Height: 2.75 m (9 ft 0 in)
Wing area: 17.2 m² (185 sq ft)
Airfoil: root:IAW-72 (Bartel 37/IIa) (6.5%); tip: IAW-72 (Bartel 37/IIa) (8%)^[2]
Empty weight: 908 kg (2,002 lb)
Gross weight: 1,355 kg (2,987 lb)
Fuel capacity: 250 L (66 US gal; 55 imp gal) in a jettisonable fuselage tank
Powerplant: 1 × Bristol Jupiter VIFH 9-cylinder air-cooled radial piston engine, 340 kW (450 hp)
Propellers: 2-bladed Gnome-Rhŏne fixed-pitch metal propeller

Performance

Maximum speed: 292 km/h (181 mph, 158 kn) at sea level

285 km/h (177 mph; 154 kn) at 3,800 m (12,500 ft)

Minimum speed: 100 km/h (62 mph; 54 kn)
Stall speed: 103 km/h (64 mph, 56 kn) ^{[citation needed]}
Range: 600 km (370 mi, 320 nmi)
Service ceiling: 8,600 m (28,200 ft)
Rate of climb: 10.3 m/s (2,000 ft/min) ^{[citation needed]}
Time to altitude: 2,000 m (6,600 ft) in 2 minutes 50 seconds

5,000 m (16,000 ft) in 9 minutes 1 seconds

Wing loading: 78.7 kg/m² (16.1 lb/sq ft)
Power/mass: 0.25 kW/kg (0.15 hp/lb)

Armament

Guns: 2 x 7.7 mm (0.303 in) Vickers E machine guns in fuselage

References

^ Cynk, Jerzy B (1971). Polish aircraft 1893-1939. Putnam. pp. 147-154. ISBN 0-370-00085-4.
^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.

External links

[Cynk-1] Cynk, Jerzy B (1971). Polish aircraft 1893-1939. Putnam. pp. 147-154. ISBN 0-370-00085-4.

[Selig-2] Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.

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