French high altitude projects of the 30s

[PhR]

In the 30s, the French Air Ministry never launched official competition for High altitude planes.
This is mainly due to the fact that the purpose of technical programs was to allocate funding for research, studies, prototypes in some cases, but above all to put manufacturers in competition to provide aircraft in the categories whose needs were defined by users.
In the 1930s, in France, priority was given to rearmament in the face of the rise of Nazism. Technical programs were therefore geared towards primarily classic categories, to renew the aging aircraft fleet.This explains the low support for inventors proposing new ideas. Most of the funding had to go into renewing the bomber and fighter fleets, and to a lesser extent training or service aircraft. Transport and connections were often forgotten.

However, many French manufacturers launched their own funds into the study of high-altitude aircraft projects. Two areas in particular have been the subject of numerous studies: sealed cabins and the power supply of stratospheric engines. All these proposals were made "out of program". Sometimes, few of them were attached to other programes, such as the NC.110 and NC.140 for A20 program (category B5).

I attach a first attempt to establish a list of such out-of-program projects.
Few of them were reactivated during WW2, such as VG.50 and Breguet 1011, facing new projects launched during Occupation period: SO.30, SO.3020, and SE.015 that became SE.1000.

 

[PhR]

The most important contribution on high altitude research of the 30s was Farman, then SNCAC after nationalization end of 1936. They built various prototypes and demonstrators, and proposed several projects: Farman 1000, 1001, 1002, NC.110, 130, 140, 150. They continued during Occupation period with SO.3020, that became after war the NC.3021 "Belphégor" with German engine.

 

[hesham]

My dear Philippe,

I know many VG.50 concepts,but what was that exactly ?,I can't find it in my collection.

 

[Justo Miranda]

- The 1930s were a time of technological progress and intense competition among aircraft manufacturers.

Prestige came from breaking aviation records such distance, altitude and speed.

In September 1932 a Vickers Vespa biplane reached an altitude of 13,408 meters.

Fifteen months later a Potez 506 managed to climb to 13,661 meters.

In April 1934 a Caproni Ca.113 modified with extended wingspan reached an altitude of 14,433 meters.

These early attempts were made using biplanes with high climbing power and supercharged radial engines that at the time were lighter than the classic V-12s.

The pilots were seated in open cockpits using oxygen via a face mask.

In 1937 experimental pressure suits began to be used, on May 8 a Caproni Ca.161 reached 15,655 meters absolute ceiling and a Bristol Type 138 managed to climb to 16,440 meters, powered by one Bristol Pegasus S, on June 30.

But all aeronautical designers knew that the future of aviation lay in pressurized cabins.

The pressurized Farman F.1000 Series monoplanes had been designed to fly at 20,000 meters, but the test program was cancelled after the F.1001 crashed on August 5, 1935. The pressurization system failed at 10,000 meters altitude, killing the pilot.

The Germans had made a great progress since their 12,740 m altitude reached by the Junkers Ju 34 in 1929. The Junkers Ju 49ba fitted with pressure cabin, flew at 14,000 meters (just a month after the F.1001 crash) powered by one L-88a V-12 engine with two-stage supercharger.

Since then Junkers continued its experiments, taking a number of patents on devices in connection with sub-stratospheric flying.

These flights had resulted in invaluable data in pressurization systems and improved superchargers.

The experience gained with the Ju 49ba was used in the construction of the Junkers EF 61 sub-stratospheric bomber, capable of carrying four SC 250 bombs at 15,000 meters altitude, sufficient to render it immune from interception.

 

[Justo Miranda]

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