The Bloch MB 150/1/2/5: Good fighters, irrelevantly used, but what a superb progeny! (Revised 25 / 01 / 2014)

The difficult beginning of an exceptional success story

(the main sources used to write the following post was: The “bible” for the MB 15x fighters: The Bloch 152, by Serge Joanne, Lela Press; The series of articles in the Album du Fanatique de l’Aviation; The testimonies published in Icare [serie: La Chasse]; Several very interesting papers in Avions and in Aéro-Journal)

The Marcel Bloch MB 150 fighter was designed by engineer Maurice Roussel, who previously designed the MB 200 and MB 210 bombers. 

If, today, this fighter may be seen as very classical, it was not the case in mid-1936. 


First, it used a radial engine, a kind of engine inducing automatically a bulky nose, signifying some loss of performances for aerodynamic reasons.

It was the first attempt of Marcel Bloch in the realm of this gorgeous category of aircrafts, the only ones able to protect a country against the enemy’s threats.

The team responsible for the conception of the prototype of the Marcel Bloch MB 150 had made a lot of work to display the newborn fighter at the end of June 1936. 

Unfortunately, the take off could not be achieved already. 

So, engineer Roussel was fired.

However, the various problems encountered were not in the plane main conception, but in a sum of little mistakes.

In late spring 1936, the political situation have changed, the “Front populaire” actually leading France: One of his numerous goals was to nationalize the defense industries. 

The leftist politicians have said that was a just principle, because all these plants were working only with public money. 


But, it was not the true motivation, which, in fact, was only to give some comfortable jobs to some incompetent lobbyists (it's more easy to see that from today).

Very quickly, the lobbyists demonstrated their poor managing qualities and the previous boss were put in charge of their ex-own plants! 

So, Marcel Bloch (as, among the others, Mr Henry Potez or Emile Dewoitine) became “administrateur délégué”, but he had not the liberty to do what he feel the best: Before any action, he needed to submit all his decisions to some committees....

Various factors explained the failure of the maiden flight of MB150. 

In the 1936’s France, the airfields, most of the time and, at first, the most used ones, consisted in rather short, bad and irregular grass surfaces (described by Jacques Lecarme, test pilot engineer in Histoire des Essais en Vol, Docavia #3, 1974). 

The landing gear of the Bloch fighter was very short, may be to favor a best sight for the pilot, but enhancing the fear of the pilot to collide his propeller with the ground. 

The 930 hp Gnome & Rhône engine was not fitted with a reduction gearbox, so the air-screw, despite its small radius (2.55 m, ~8.5 feet), was completely inefficient (once in flight, the extremities of the blades exceeding too much Mach 1).

A fine general conception

Some other countries also used of radial engines for fighter planes (USA - P35, P36 for the USAF, F2A1, F4F3 for the Navy, USSR Polikarpov I 16, Italy CR42, G50, MC200,  and Japan Ki 27 and A5M4).

In fact, the main layout of the Bloch was aerodynamically and practically far superior to all these aircrafts. 

Bloch MB 150 - (after her maiden flight)

For example, her wings was very thin (14% of thickness) and her fuselage was well streamlined. The only clumsiness of the Bloch design may be found in details (which were all successively eradicated).

All the fighters of that period shared a tail wheel, inducing a nose up attitude at rest and during the very beginning of the take off. So, the pilot views were blinded by the bulky engine. 

The disturbed lines, rather frequent in the design (illustrated by, e.g., the Fiat G50) of her contemporary concurrent using also of radial engines, may be explained by the introducing of a camel hump to offer a good forward view to the pilot. 

Marcel Bloch retained a very advanced pilot position, rather similar to that of the Breda 65. Such a solution was aerodynamically more efficient than the camel hump.

During five months, the work on the MB 150 seemed to be stopped. But early in 1937, Marcel Bloch resumed the work on the MB 150. 

In French specialized publications, one can read - to explain the revival of the MB 150 - the French Air force Staff was concerned about possible shortage affecting the Hispano-Suiza 12 Y engines needed for the Morane 406 fighter.

In my own opinion, such a tale is very difficult to accept: 

The Air Staff had previously chosen the Nieuport 161. 

But, after her crash, the Nieuport was vilified, excluded from the contest (!) and the active lobbying of some politicians achieved the ordering of the Morane 406.

However, all competent military French deciders - yes, they existed -  were knowing perfectly that the performance losses induced by such an order could be catastrophic. 

So, they sent some cautious messengers to MM Bloch, Dewoitine and Renault to ask them to resume their works.

As may be you know, the Dewoitine 513 used the same engine as the Morane 406: This is the proof that the lack of Hispano engines was not true, and the French military deciders displayed a real lack of moral courage... against the lobbyists. 

This behavior is always possible in every country...

Nevertheless, the perfecting of the Bloch fighter required a lot of modifications. 

Marcel Bloch had previously never been involved in the design of any high performance plane. 

So, as any engineer creating a fighter dynasty, he had (as all his staff too) to learn all the high speed aerodynamics and its associated structural consequences.

The wing was enlarged several times, the landing gear became taller, the engine cowling was slightly refined and the engine was replaced by a slightly more powerful one.

The result was the first flight achieved the May 4, 1937.

A new engine was already fitted, using a 2/3 reduction gearbox instead a direct drive and allowing the use of a 2.9 m in diameter air-screw: The top speed reached 434 kph at altitude (the same as the one of the Morane fighter).

The engines appeared always as insufficiently cooled for two reason:

a)     using of the 85° octane gasoline instead of the 100° one,

b)  the very long time of ground rolling expected by some statutory (but completely irrelevant) usages.

Even the engines were not bad at all, they became so powerful that a complete redesign was needed to take into account a lot of new constraints. 

This redesign was done, leading to the 1600 hp class Gnome et Rhône 14R Météor, unfortunately a little too late.

Overwhelmed by a lot of shortcomings, the engine makers were not able to define a cowling which can be aerodynamically efficient, allowing to satisfy the pilots who needed the highest possible speed, and also mechanically efficient, allowing to satisfy the mechanics in minimizing any wasted time for them.

So, like his colleagues Amiot and Bréguet, Marcel Bloch should have independently developed a lot of cowlings for the same GR 14 N engines. 

OK, may be, do you think it was stupid to do three times the same work while Hitler and his Nazi Reich was so close of  triggering the WWII. You are right...

With a new cowling, a larger air screw and a spinner, the MB 150 M (for modified) achieved a top speed of 480 kph. After this reasonable achievement, the radio equipment and the armament were fitted.

A new experimentation of cowling seemed to be necessary, with a diameter of the air intake started from 0.85 m to be enlarged up to 1 m – this being the standard fitting on the MB 151 - and to decrease again to 0.85 m when cooling flaps were fitted.

MB 151 prototype, with the efficient cowling of 0.85 m in diameter - photo on the site aviafrance

Unfortunately, this later cowling was never used for the MB 151... 

The top speed of this last fighter was, at least, 460 kph without exhaust pipes. 

serie MB 151 with the huge air intake of 1m in diameter
the original legend is MB 152, but its impossible: it lacks the wing cannons HS 404

With the new cowling and exhaust pipes, her top speed could have reached more than 480 kph, a speed similar to that of the Amiot 350-01 used by General Vuillemin to fly to Berlin in summer 1938, at a 440 kph average speed with narrower air intakes. 

And we know today, the cooling of her engines was good above 240 kph.

How irrelevant was such a decision! 

With a speed of 460 kph, the MB 151 experienced some difficulties to catch some bombers. 

Fitted with the best cowling and the exhaust pipes, the MB 151 could had reached a far better fate.

With the narrow air intake of the late cowling, fitted together with exhaust pipes and the more powerful GR 14 N 49, the MB 152 prototype achieved a top speed of 515 kph, a jump of 30 kph! A narrower air intake – 0.80 m – was used for the latest operational Bloch fighter, the MB 155.

All these cowling problems were responsible of one complete year of delays. 

May be, Marcel Bloch could have taken some advantage if he had chosen the efficient - but very complicated for maintenance purpose - Mercier cowling...

MB 152 on aviafrance site - the leftest plane is fitted with the "good" cowling, the following, not, but all display their  starboard canons !

Nevertheless, the most interesting thing is how strong was this experiment for him. 

The MB 150, starting with a to speed of 434 kph, culminated, with the same layout, to 515 kph. 

This progression of 80 kph was obtained together with better handling qualities and better lateral stability and, even, a complete redesign to divide the aircraft in modular blocks for a faster building: a lot of work in a very short time

Another complete redesign was done by engineer Lucien Servanty (who, later, designed the supersonic Concorde) late in 1939, to take advantage of the powerful GR 14 R engine, ending at the gorgeous MB 157, with 2 m² larger wings, an airplane able to fly faster than the FW 190 (710 km/h with military power - 15 minutes max - and 680 kph for normal max power,  and the climbing to 8000 m reached in 11').

In action

The MB 151 was used by at least the GC II/10 and III/10, in the French Air Force, and by the Aéronavale squadron AC 3.

The results of their fights is not bad, for example, one pilot of the GC III/10 downing a German bomber and a Bf 109, but was wounded and forced to land during the same combat by other German fighters.

The AC 3 fighters were most accustomed to protection missions and experienced successfully their MB 151 to protect their bombers, some convoys in the Channel and their own airbases.

When, the June 15, 27 Italian fighters attacked the naval base of Toulon, the alert was given very late. 

The three patrols of the AC 3 took off just in time (a few time before noon). 


They were overwhelmed (9 vs 27), 2 pilots were killed in action, another one (SM Le Bihan) died after a forced landing ended by a collision with a tree. 

The peculiar fact is that this pilot, before his forced landing, collided voluntarily with a Fiat CR 42 fighter, which was downed.

However, this first encounter with the very nimble CR42 biplane resulted in 3 Italian fighters downed. 

According to the testimony of a French artillery officer, they have not be destroyed by the D 520 of the GC III/6 which were still on the ground.

Among these 27 seven Fiat CR 42, only 2 returned to their base... As it was very frequent in this war, the Italian want not recognize the value of the French fighters, as the Germans have done, preferring being downed by British ones. 

This was the same behavior for the British in North Africa against the Italian fighter, preferring to be downed by Germans.

This war was a racist one, but you may know that...

As it was said the Bloch fighters were unable to cross thee Mediterranean Sea, the AC 3 pilots achieved that job successfully before the June, 25, 1940, using a refueling at Ajaccio, in Corsica, and landed safely at Bône (the antique Epone and now Annaba).

Another country fought with the Bloch 151 fighters: Greece. 

Unfortunately, when the Greeks ordered 24 MB 151, the Germans were about to launch their Fall Gelb against France and all democratic countries of Western Europa. 

So, only 9 MB 151 were delivered to Greece. All of them have been previously used by the Armée de l’Air and their engines were worn out. 

The Greeks having got no spars, so they used only 5 MB 151 fighters, the others being used as spars sources.

Nevertheless, these fighters seemed to be the best fighters of the Royal Hellenic Air Force. 

They appeared fairly efficient against the Regia Aeronautica. 

But, when the Germans interfered, only 2 were still airworthy, and in few days they were eradicated.

The Greek pilots were efficient to protect numerous strategic points and they have got from 5 to 7 victories! A rather good performance against so overwhelming forces!

The Bloch MB 152 performed very better than the Morane 406 and scored very better. 

Even in the worst definitions, they can fly at least 30 kph faster, but those which were fully operational were able to fly at least at 505 kph at altitude, to climb to 4000 m in 6’12” and to reach 8000 m in less than 16’. 

With a VNE of 660 kph (IAS), they were able to dive faster than the Curtiss H75 (VNE : 550 kph IAS) and also faster than the actual Hurricane (Jean Nollet, in Album du Fanatique de l’Aviation, #11).

Their armament was the strongest of the world until the appearance of the FW 190 in 1941.

The fuel tank was special, allowing absolutely any negative g maneuver.

Finally, the structure was especially robust, allowing to some pilots to return home in spite of having been hit by up to ten 20 mm shells and more than 100 bullets machine gun!

This quality was essential in the overwhelming superiority of the Jagdwaffe.

Nine Groupes de Chasse (18 squadrons) of the FAA used these fighters and claimed 188 victories, among them there were 51 Messerschmitt Bf 109 and 27 Bf 110, to be compared with the 187 victories claimed  by the twelve GC (24 squadrons) using the Morane 406.

The most successful Bloch 152 equipped GC was the I/8, claiming 44 victories among them 36 were confirmed. The best GC using Morane fighters claimed 36 victories among them 29 as confirmed.

I have not included the local patrols protecting airfields or aeronautic factories, but they claimed 18 victories among them 12 were confirmed.

After the Armistice, 320 Bloch fighters were in the Free Zone of France: 49 MB 151 (20 needed some repairs), 245 MB 152 (72 needing some repair) and 8 MB 155.

This assessment is not bad, knowing the bad conditions in which the fighting was engaged.

Irrelevant starting position

As you can see on the map of the North part of France, all fighter squadrons were firmly stuck to one specific area, each one of these areas being dubbed groupement. 

Some of these “big” units were gathered in Zone d’Opération Aérienne, the two ZOA illustrated in this map gathered 630 single engined fighters over a grand total of 900 for all the French Air Forces (including the Morane 406 available in Lebanon[!] ).

The distribution of the fighter squadrons for May 10, 1940, seems rather odd!

Personal document of the author - Locations of the French fighters groups for the May 10, 1940

Five GC were close to Rheims, the two nearest from this town being equipped with Curtiss H 75 fighters, the 3 others with Morane-Saulnier 406. 


Four others GC (1 on Bloch 152, 3 on MS 406) were a little more far from the Belgian border. 


All these GC seemed dedicated to the protection of Paris and also to protect the limit between the tough Maginot Line and the less protected one (Ligne Maginot Prolongée).

Four GC (2 equipped with MB 152 and 2 with MS 406) were stuck in the immediate vicinity of the West Belgian border: Their squadrons could have no delay to escape any enemy attack.

There was 5 GC in the vicinity of the Seine river, 4 with MB 152 and 1 with MS 406.

Four other GC were on the East part of this map, 2 equipped with MS 406, 1 with H 75 and 1 with MB 152.

The last  Bloch equipped GC, the III/9, was in protection of Lyon. 

It claimed only 4 victories during the Battle of France. 

This poor score is the consequence of an irrelevant warning system as also of the bad positioning of this GC.

One can see the huge empty spaces with no defense squadrons. 

The organisation by GC had divided by a bit more than two the number of the airfields, allowing some reduction of the mechanics. 

But the take off points were also reduced by the same amount, and, knowing the poor training of most of the AA artillery protecting the airfields, the Germans attacks were more “juicy”.

The Bloch fighter entering service relatively late, they were not positioned in the place were they can be quickly engaged in skirmishes during the Phoney War. 

In the actual France, somebody thought the fighting did not give experiment!

As several hundreds of Bloch fighters were already produced, it could have been possible to position their squadrons in first line. 

The obsolete Morane 406 could have been used to protect the factories and the great cities.

The Bloch 155 entered service in June 1940. 

She was used a much more sophisticated cowling, a more streamlined fuselage.

A 700 l fuel tank was fitted (300 l more than the MB 152), as, also, a 40 mm thick triplex windscreen. 

The top speed published of 520 kph. 

This is likely the lowest top speed accepted by the French Air Force for fighter just out of the plant. 

The true top speed could have been about 530 km/h, the same than the Bloch 174 recce twin engined which used the same engines and the same cowling.

Captain Coutaud have got a victory with her. 



A more powerful engine (~1200 hp) was about to be available for her. 

Bloch MB 155 - on a muddy airfield, but showing all the differences with the MB 152.  The triplex windscreen is beautiful.

One prototype of the MB 155 flew with 4 Hispano-Suiza HS404 cannon...  


The last Bloch fighter belonging to this family was the Bloch 157. You may read my post on her: Click here.

Conclusion

In 1940, despite all the success obtained by Marcel Bloch, the lobbyists have won, and Marcel Bloch was fired from his job. 

After the defeat, as a jew, he was put in custody by Vichy police near Lyon and, after the German occupation of the so-called “free” France, at Drancy. 

In August 1944, he was deported to Buchenwald nazi concentration camp, where he was protected by French communists militants (!).

He returned home in 1945. In 1946, he change his name to Bloch-Dassaut (the name his brother Darius had used during the Résistance). 


Three years later, he changed definitively to Dassault.

At the Liberation time, the aeronautics bureaucracy had published a new program for a very heavily armed fighter. 

The nationalized companies were working on very heavy fighters, the best one being the SO 6020 Espadon designed by Lucien Servanty.

But Marcel Bloch did not think that was a relevant specification. 


He know better the financial and technical problems in the actual France than the so-called high-engineers, and preferred a much more light plane: That was the MD 450 Ouragan, which used a lot of structural solutions of the MB 150!

The lesson which one may derive from that story is how important is that Marcel Dassault had demonstrated a perfect capacity to adapt himself and his planes to any situation, and he had learn how essential is the independance of his Nation.

The Luftwaffe is attacking ! How the French Air Forces reacted between 1939 and 1940 ?

Between September 1939 and June 1940, the French Fighter Command displayed against the aerial threats generated by the Third Reich, at best, average, often weak or completely absent, reacting capabilities. 

Its weakness to detect incomming planes, as to evaluate the threats and to propagate the air-raid warning changed for the worse after the breakthroug of the Guderian's armoured divisions at Sedan.

Somebody, in France, cloaked hermetically the causes having induced this bad reactivity during the ten following years. 

Later, the French memories vanished slowly because a lot of the actors of the aerial warning, its transmission and its evaluation, disapeared without any public debriefing.

Indeed, one can understand a little they had little motivation to remember what they have lived - they had few good achievements to claim. 

Nevertheless, I cannot understand why a kind of censorship on this subject occured since dozens of year until the present days.

The Lt-Col. Michel Marias (Grp III/3) summarized the perception of the fighter pilots (in Icare):
War is also a matter of organisation. War began - and continued for us - so to speak, without any warning and intelligence network. Yes, they were lookout men. But it was as if they were on guard forever in the opposite café! The few times they achieved to detect a raid, more often than not, they could not transmit us the informations.

It was certainly possible to overcome such a disaster. We prooved that by developping our own warning network. As early as an ennemy attack was known, even very far, all available fighters took off. So, we were able to attack the ennemy bombers as soon as they were in sight; Even we miss to catch them, no bombing were able to destroy our planes on the ground.


Moreover, some fighter unit commanders seemed not to have understood the need to train their pilots to take off very fast.

The fighters took off only on warning or following a schedulded time. As often as not, only three aircrafts are involved. 

Obviously, a quick reactivity of the Fighter Command was not a clear priority for the French Air Staff. 

The consequence of such weakness was the loss of about hundred (at least) fighters (and, obviously, many military aircrafts of other kinds ), while any loss was tactically forbidden. These results were strongly aggravated because any aircraft in need of repair - even the esasiest ones - had to be destroyed when German troops became too close.

A premonitory failure to interception

The July 2, 1933, Benito Mussolini sent the General Itallo Balbo with 25 flyingboats bombers to achieve a spectacular trip starting from vicinity of Roma to Chicago and returning home (map here). It was also a very clear show of force, with 2 legs crossing the Atlantic Ocean. 

The second leg skirted France by her East border.


As usual during the third French Republic, at the very last moment, the French deciders ordered a French Fighter squadron, based in Strasbourg, to meet the Italian planes to give them an Honor escort for a little while.

Unfortunately, the French squadron failed to catch the Italian flying boats and many of the newspaper reporters, having seen that, reported loudly that failure.

The French newspapers, which were laughing about that failure, were nevertheless unable to understand the real causes of the failure. 

They wrote that the problem stayed only on the top speed of the fighters. 

But the real question was the time taken to detect the Italian bombers, to warn the fighters and to put them at the desired altitude.


But it was not possible.

First, the fighter was the Nieuport 622, straight forwardly issued from the Nieuport 42 (just clearly more stable and robust), the winner of the 1923 (!) fighters contest. 

At sea level, her top speed was 270 kph,  at 5000 m, she achieved 250 kph. 

It was an obsolete fighter in 1933, but very cheap, robust and very maneuverable. 

About this last quality, I rely completely on the judgment of Roger Sauvage, a good fighter ace (16 confirmed victories), belonging, during the 3 last years of WW II to the GC 3 Normandie-Niemen elite unit. 

It was possible to the French War Ministry to buy much more modern planes, as the all metal Nieuport 82 or the Dewoitine D 27. 

But it seemed absolutely urgent to conceive and buy pharaonic battleships, for bad reasons 

(the Germans had launched the pocket battleships, the Italians had refurbished the Cavour series, and so on. 

All these - beautiful - toys demonstrated during the war the absolute stupidity of the men who ordered them. 

They were completely useless apart to become the most ruinous coffins ever build for their crews. 

The death toll of the eleven most famous ones - belonging to all countries at war - was about 14000, according to Wikipedia.

Unlike the aircraft carriers, none of them had achieved any serious tactical role. ) 


The Italian flying boat used was the Savoia-Marchetti S 55. 

A very good plane, several times upgraded, and some 10 kph faster than the old French fighters. 

OK, it was a good occasion for Balbo to ridicule France and to strengthen the confidence of the Italian peoples in Mussolini. 1

It was very simple for the Italian pilots to fly above the scheduled flying level and, when the French fighters were taking off, to put the planes in a very shallow dive, accelerating the speed by at least 40 or 50 kph, leaving the so-called Honor escort stunned. 


Nevertheless, I'm sorry for the newspapers and their writers, any fighter plane was ever able to intercept any heavy plane if they belong to not too distant generations. 

Obviously, in any case, the fighters must took off in time. 


If the air-raid warning organisation were really efficient, it could be easy for her to warn since Colmar, at least. 

So, the French aircrafts could be sent in the Air earlier and if they were flying at a sufficient altitude, they could catch easily the Balbo's unit. 

Another solution would have been to dispatch a Morane 225 squadron to Strasbourg, with a 50 kph superiority in top level speed.

Prerequisite for any interception

To intercept any aerial intrusion, before the radar became operational, induced some needs:

•  Knowing that the enemies are attacking us, sufficiently in time to warn the fighter squadrons. It is a problem of extracting a pattern, leading to the identification of a clear signature. E.g. for an audio signal, recognizing the sound of German engines, or, for a visual signal, identifying the German warplanes.

• The nearest fighter squadrons must be warned to gather their pilots and the mechanics to prepare quickly the take off.

• Simultaneously, the Air Force High Staff must also be warned. Then, it is possible to define how strong is the attack. This point will induce two possible reactions: 

• the capacity to engage distant squadrons ; 
• the relevance to launch a counter-attack.

• If the attack seems to penetrate deeply in the friend territory, one must define the trajectory to anticipate what are the most probable targets. So, the AA guns crews must be in place as also the team in charge of discriminating the friends from the foes.

• Launching the fighter squadrons to fight the enemy attackers before they had damaged any of the friendly installations, plants and so on. This, obviously, implies:

• the pilots must quickly be seated in their fighters;
• the heading for the interception must have been communicated to the pilots;
• all aircrafts must take off quickly and climb like the hell to the relevant level. 

May be, I forgot something...

 The French warning system in 1939 (source: L'aviation militaire Française en 1939, P Barjot)

In this system, the first technique is the optical one, with the use of field binoculars, because, in many cases, the identification of the planes is more accurate (depending of the training of the sentries). In UK, the RAF used such means even during all the Battle of Britain. 

However, during the night or with bad observation condition, this method was useless. 

An all-weather method was needed and the simplest one was an audio method. 

Personal collection of the author - This system is only acoustic: 2 soldiers defined the sound location
with their wheels, the 3rd transmitting the heading

The devices (in French: télésitemètres) gathering the sound from very large ear trumpets in two audio channels for each observer. 

So, the sound was perfectly stereophonic. 

An individual plane (spy plane for example) was detected at least at 10 km, and, with good conditions, sometimes much more.


I have personally known, as an University student (in the 60's!), a woman (Professor in neuro-physiology at the Sorbonne University) who served as a volunteer auxiliary during the Battle of France in 1940. 

She said us how precise was such a system.

Nevertheless, most of these devices have been in service at the end of the WWI and were quite useless when the enemy planes were flying above 320 kph. 

To my knowledge, there was no electrical amplification of the signals. 

If it have been proceeded, the warning distance could have been twice the unamplified one and it could be possible to record the true sound of the German raids, allowing a more easy discovery of the different sound signatures for each German, French and Allied planes. 

The audio-devices were laid at about every 10 km from each other on some lines in order to create mesh of about 100 x 100 km in the warning network. 

Personal collection of the author - schematic view of a mesh of the French Aerial Defense warning system

In this layout, several audio devices were connected by telephone to a relay station which had to transmit the warning by the same way to a local Aerial Defense (DAT) Intelligence Center, which, at last, warned the fighter squadrons.

In one single mesh of this network, there was an average of 400 audio-devices, involving may be 20 to 40 relays. 

One can understand the amount of time wasted for the fighters...

Most of the German bombers were cruise flying at ~360 kph (100 m/s), so 10 km must be translated as 100" - 1 minute and 40 seconds. Just the time to warn.

Such a system would have been efficient in 1918, it was completely obsolete in 1939.

Worst, there was absolutely no possibility to elaborate a synthetic view of the intrusion!

Remote communication

As it is easy to understand, the remote communication is a key of any warning system.

The most ancient known system was the messengers, illustrated by the runner of Marathon.
It was efficient for relatively short distances (from 20 to 200 km). In modern times this method is still used. 

General Charles De Gaulle reported in his War Memories (l'Appel) he used this method during the battle of Abbeville in May 1940, with motorcyclists.

The first true remote system was the Chappe telegraph (1790), for which the word telegraph was created. 

The French Revolution has developed quickly this modern system, which allowed a considerable change in all kinds of communications. 

At the same time in the same Nation, the Vendean rebels used their windmill as telegraphic station:

Example of windmill orders on the site of the Puy du Fou Park

With the electric telegraphy - middle of the XIX Century - and some years later, the radiotelegraphy, the possibility of instantaneous transmissions changed more clearly the situation. 

The Chappe telegraph needed only the human forces. The electric one needed an electric plant and the radiotelegraph implies as many electric generator as numerous are the emitters or receivers. 

During WWI, the French Army was leading clearly this trend.
A good series of synthetic articles on these subjects may by found in the gorgeous French review GBM.

Nevertheless, after the fall of the Third Republic, all French fighter pilots complained about the use of the civilian PTT network for the warning transmissions.

The best is the enemy of the good

A radiophonic emitter/receiver used to transmit short and clear messages would have induced very faster execution. 

But its needed a good and complete experimentation.

When the Finnish commander Gustav Erik Magnusson arrived in France in 1933 for an embedded period in a French fighter group, he was very disapointed by the total absence of radio-communication, a mean his colleague and him used daily since 5 years.

This illustrate perfectly one of the French problems: Any technical innovation induced always a lot of discussions about the norms needed to avoid any shortcomings. 


The first perceived shortcoming was the use of the common language which is a not coded one. 

That's true, nevertheless Germans used a lot the radio-communications in their natural language. 

Unfortunately, the French officers appeared unable to use that as an advantage...


The second shortcoming was likely foreseen by some excessively rigorous engineers.

They thought that in a squadron, the officer in command needed to be heard by all pilots, so they have imposed to use of 2 separate frequencies, one to receive, one to emit. 

Obviously, the officer in command was most of the time stuck in the airfield and cannot steer his squadron, but he had a good radio station in a car... 

This is the reason for which you can see two antenna for each French fighter of this period.

When Seargent Pierre Boillot (see in the review Icare, la Chasse) saw the squadron of German Captain W. Mölders attacking his own team mate, he must remain silent because he cannot emit any warn to them. 

After that bad experience, all the radios of his group were put on the same frequency... too late.


The responsible engineers, apparently, had never thought that fighter pilots need to speak together! 

This behaviour was enhanced in 1936 when the Air High Staff ordered multi-engined planes to command the fight. 


Such an idea was a very advanced one and the AWACS are an excellent materialization of this concept, but, as the first experiences demonstrated in 1938, it was only a dream.

Some late promises... 

In his book on the French military Aviation in 1939, Pierre Barjot (later admiral in command of the French fleet during the Suez operation in 1956) underlined the key role of the climbing speed. 

The choice of the Morane 406, very bad in that exercise, was of no help, as was the local anchoring of the fighter squadrons.


A better arrangement would have been to centralize all the informations in a unique building put near the center of France (e.g. Poitiers). 

In such a case, the High Staff of the French Air Forces would have stay there to give instantaneous answers to any attack.

However, late in 1939,  some generals seemed to be awaken. They launched works to equip France with radars. 

French engineers were at work on this subject since many years (see that site).

The production models were able to detect the incoming aircrafts at 80 km, i.e. 13 minutes before the attack. 

They are installed the June 5, 1940, too late... unfortunately. 



One may link to such an idea the experimental ordering of 18 Dewoitine 551 fighters at the end of 1939.

click here to read the post describing the climbing capability of the Allied fighters during the Battle of France.