Potez

Potez (pronounced [pɔtɛz]) was a French aircraft manufacturer founded as Aéroplanes Henry Potez by Henry Potez at Aubervilliers in 1919. The firm began by refurbishing war-surplus SEA IV aircraft, but was soon building new examples of an improved version, the Potez VII.

History

During the inter-war years, Potez built a range of small passenger aircraft and a series of military reconnaissance biplanes that were also licence-built in Poland. In 1933, the firm bought flying boat manufacturer CAMS.

The company was nationalized in 1936, following which it was merged with Chantiers aéronavals Étienne Romano, Lioré et Olivier, CAMS and SPCA in order to form the Société nationale des constructions aéronautiques du Sud-Est (SNCASE) on 1 February 1937.

Potez's factories in Sartrouville and Méaulte were taken over by SNCAN and the Berre factory went to SNCASE.

After World War II, Potez was re-established as Société des Avions et Moteurs Henry Potez at Argenteuil but did not return to the prominence that the company enjoyed prior to nationalisation. In 1958, the company bought Fouga to form Potez Air-Fouga, but when Potez's last design, the 840 (a small turboprop airliner) failed to attract customers, it was forced to close. The remaining assets were purchased by Sud-Aviation in 1967.

Potez 506

The Potez 506 was a version of the Potez 501 French single engine observation aircraft, specially modified to capture the World absolute altitude record. In September 1933 it set a new record at 13,661 m (44,820 ft).

Design and development

The Potez 506 was a modification of the Potez 501 observation/bomber aircraft, itself derived via the Potez 50 from the widely used Potez 25, first flown in 1926. In 1932 Cyril Uwins set a world altitude record of 13,404 m (43,976 ft) in a Vickers Vespa VII, which the Potez 506 was designed to better. Flown by Gustave Lemoine, it reached 13,661 m (44,820 ft) on 28 September 1933, an altitude limited by icing of the pilot's eyes as he sat in his open cockpit. He used oxygen but had no pressure suit. The flight, made from Villacoublay, lasted 2 hrs 5min.

The record breaking airframe began as a Potez 501, which was the Potez 50 with its inline, water-cooled 520 kW (700 hp) Lorraine 12Fd replaced by a 520 kW (700 hp) Gnome-Rhone 14Kbrs Mistral Major radial engine. The Potez 506 had a similar 14-cylinder. two row radial engine, the Gnome-Rhone 14Kdrs Mistral Major, which had its power increased to 600 kW (800 hp) at sea level by an increase in compression ratio from 5.5 to 7.25 and an improved supercharger which could maintain this output to 6,000 m (19,685 ft). It drove a three blade propeller. In addition, the upper wing span was increased by 26% to 18.6 m (61 ft 0 in) and its area by a little more. 100 kg (220 lb) of empty weight savings were made. The pilot sat in the rear cockpit, rather than from his usual forward position which was covered over and used to house the barographs and batteries. Like all of the Potez 25 derived aircraft, the 506 had an all wood structure with fabric covering apart from around the engine and was a single bay sesquiplane with shorter, narrower chord lower wings and outward leaning interplane struts.

Potez 53

The Potez 53 was a racing aircraft built in France by Potez to compete for the Coupe Deutsch de la Meurthe in 1933.

Design and development

The Potez 53 was a low-wing cantilever monoplane of conventional design with an enclosed cockpit for the pilot. The main units of the tailskid undercarriage retracted outwards into the undersides of the wings (There is something wrong here—maybe "and" left out. BAB) . It was powered by a supercharged nine-cylinder Potez 9B radial engine driving a two-bladed fixed pitch propeller. The engine was specially designed for the competition, which called for engines of less than 8 litres (490 cu in) displacement.

Two machines were entered for the 1933 Coupe Deutsch de la Meurthe. The first (racing no.10) was flown by Georges Détré, who won first place, covering the 2,000 km (1,200 mi) closed-circuit course with an average speed of 323 km/h (201 mph). The other (racing no.12) was flown by Gustave Lemoine, who retired after completing the fourth lap.

Following this success, a new machine designated the Potez 533 (or 53-3) was built with various improvements for the 1934 race, including an uprated engine delivering 350 hp (260 kW) driving a Ratier variable-pitch propeller, slimmer and more streamlined fuselage and redesigned wings of increased area. One of the two aircraft entered the previous years was refurbished as the Potez 532 (or 53-2), to act as a backup in the competition. The engine was uprated, its fuselage was slightly lengthened for aerodynamic reasons, the wing was further enlarged and additional flaps were installed between the fuselage and ailerons.