lundi 9 avril 2012

The experimental ordering of fighters: A reaction against the Hal complex (revised July 27, 2017)



Three fighters have been ordered in experimental series by the French Ministère de l'Air while they have been previously rejected by the official technical survey.



The big concern of General Vuillemin


The choice, at the end of 1936, of the Morane-Saulnier 405 as a standard fighter by the Armée de l'Air chief of staff, general Fécamp, a friend of the Ministre de l'Air, Pierre Cot, appeared as a big mistake to all high rank airmen soon after the brilliant performances of the Messerschmitt Bf 109 in the Zürich Meeting of 1937. 

Worst, the inability of the Morane-Saulnier factory to fulfill quickly the orders triggered a new approach about the standardization concept.

At the end of 1938, the MS 406 fighter was not able to master the older Spad 510 fighter in mock combats.

The Armée de l'Air stroke back in two ways. 
  • The first one was to favor new orders for different existing fighters : The Bloch 150 M (which became the MB 151 and her progeny), the Caudron 710 familly and the Curtiss H 75 (P 36).
  • The second one was to  favor the creation of a lot of new fighters, even if the concepts used were very different from the official programs.

We know, today, that 3 fighters were ordered, and for 2 of them, the information was given only by the German troops!

These fighters were ordered without the CEMA endorsement!


The Dewoitine 551 


The Dewoitine 551 have been initially rejected without any trial because the prototype, the Dewoitine 550 - a very promising world airspeed record breaker, reaching 705 kph at 6,500 m - did not respond to any official program.






Dewoitine D 550 prototype 

The performances of the D 550 resulted from a very streamlined shape, and a take-off weight of only 1,800 kg (rising to 1,950 kg at the end of May,1940). 

Nevertheless, the famous test pilot (and French Air Ministry missi dominici), Michel Detroyat,  was sent by General Vuillemin (Chief of Staff for the French Air Force) to evaluate this fighter.

He was highly enthusiastic, suggesting to increase the wing area of 2 m² to take into account the additional weight of the weapons.

His report had triggered an immediate order of the Armée de l'Air for 18 fighters.

The D 551 fighter retained the main structure of the D 550. 

The maximum drag area was 0.889 m², to compare with the 1.02 m² of the D 513 and even the1.056 m² of the D 600 fighter designed for the Spanish Aviation for1942-4.

The length was 8.20 m (D 520: 8.60 m).

Obviously,with armament, armor and oxygen, the take-off weight rose to 2,150 kg.

So, the wing area was increased, rising from 10.79 m² to 13.048 m², to conserve the wing loading of 165 kg/m² of the D.520. 

The thickness of the wing was 17 % at the roots and 10 % at the tips.





Dewoitine 551 as seen during the 1941 winter - picture from Aviafrance


The top speed was (at least) 650 km/h and the climb to 8,000 m was better than 7'. 

The only shortcoming regarded the weapons : Five light MGs (another possibility was to have only one 20 mm gun in the engine).

Three D.551 were about to fly at the cease-fire time, and sixteen in various stage of finishing.



The CAO 200


The CAO 200, produced by the Nieuport team, had very smart wings (the lay out of the plane anticipated almost the one of the Mig 21) but she had never received the expected Hispano-Suiza 12 Y 51 engine, instead she was fitted with the poor 12Y31 .

The top speed was 552 kph and the climb to 4,600 m needed 5'35".

One may translate such a value as ~4' 50" for 4,000 m.




CAO 200 - picture from Aviafrance  


These performances were better than those of the D.520, being obtained with less power and 1,000 m lower.

Nevertheless, the French technical survey rejected the aircraft. The same extra test pilot evaluated the CAO 200, found her very easy to fly, very maneuverable and appreciably fast.

Twelve fighters were under construction with Hispano-Suiza 12 Y 51 engine (allowing them a top speed close to 595 - 600 kph) when the German troops irrupted in the SNCAO plant.

One noticeable property of this fighter was the extensive use of electric welding in place of the traditional riveting for the light alloys monocoque structure.



The NC 600


The NC 600 was issued from the Hanriot 220 twin-engined fighter of 1936. Her teething troubles were numerous and were fixed rather late. 

Initially, the Hanriot 220 was found very unstable, what was attributed, as usual in the CEMA, to insufficient horizontal tail surfaces. 

However, if you look to the photography below, you can see how abnormal was the huge cockpit canopy ! 

In fact, the initial fighter could have been an interesting single seater.




Hanriot 220 as seen initially - See how the cockpit canopy masked completely the tail surfaces at slow speed...


However, the performance were good, as the fighter top speed was 542 kph and her climb to 8,000 m was 14'.





CAO 600 - picture from Aviafrance   


The CEMA rejected the fighter, because it favored unduly the very heavy and more powerful SE 100 fighter (580 kph at 6,000 m).

They were also involved in the ordering for the Lockeed P38 Lightning, which, deprived from her turbo-supercharger (by a US Senate law protecting the American military advances) would have been very slower, unable to reach a normal climb ability, and to summarize, an aircraft of very little utility (as it was judged by the British experts in 1941).




One NC 600 captured by the German troops - the air intakes were very narrow !


Nevertheless, the German soldiers discovered six NC 600 under construction when they were occupying the Bourges facility.



Some lessons ?

Indeed, this very unusual behavior of the French Air Ministry looks like a tool to bypass his own technical surveys!


Why such things happened ?



Because, among the 3 star programs launched in 1936-1937, two (Morane 406 and Potez 631) have given pleasant planes plagued by alarmingly low performances. 

The third (LéO 451) although being relatively fast and very maneuverable in flight, was very hard during the take off (abnormally high rate of fatal accidents : 20% of the total existing strengths were written off before the May 10 !).

Moreover, two of them (Morane 406 and LéO 451) were very slow to build, inducing the need to dedicate all aeronautic plants to build these bloody aircrafts (OK, I know the Spitfire needed the same time than the Morane, but she was undoubtedly a considerably better fighter deserving to be manufactured in large amount - I must add that, considering the 22,000 hours needed to build the Macchi MC 200, the real building time of the MS 406 was likely similar).

The method used here to overcome this clear "viscosity " affecting the whole selection process, looks typically like a Darwinian process.

The official test pilots were seen as "too much skilled" to be representative of the main population of military pilots.

So, the parallel trials made by an acknowledged super test pilot illustrated a clear adaptation to a new, very fast method to gave a clear view to General Vuillemin about any new aircraft.

That displayed also a clear refusal of previous methods which had given so much abnormal results.


If France did not be defeated in June 1940, the results could have been very interesting.

The trial-and-error method had proved its superiority to the previous one, but we don't know exactly the causes of their failures, even some corruption might be suspected in some cases.

The experimental squadrons sent to the front could give a more relevant judgement (as it was the case when "normal" pilots had flown the Amiot 351 bombers, they felt so delightful to fly).


That may also be interpreted as a mechanism of resistance, as those developed by any living organism against cancer.

This French Air Ministry bureaucracy was a very creation of this Ministry. 

It was growing day after day, developing - by chance - some good ideas and methods. 

After a long struggle to be heard, mainly because aircraft maker were very short of money, it had developed its own rules raised at the level of God's laws.

So, it became a true monster which destroyed a lot of the French aerial capacities.

One may compare this process to the Hal computer in the Arthur C. Clarke's: 2001, A Space Odyssey

The men were obliged to bypass the tool they needed to survive...

I wonder why the French parliament members, who represented the Nation, had not detected such a bias.

If they have known it, they could have reduced this excessive independence so as to give the power to the real users: The front pilots.

But I wonder also if these PM like to work...



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