lundi 13 juillet 2015

The Loire-Nieuport 401 / 411, fighter-bombers of the French Navy in 1940, used to stop German tanks! (enriched 07 / 31 / 2018)

In the 30’s, the French Navy wanted its own diver bombers


Les Bombardiers en Piqué Loire-Nieuport: du Ni 140 au LN 42, Arnaud PrudhommeTMA, 2005;  

Nieuport 1909-1950, Rosenthal, Marchand, Borget and Bénichou, Docavia #38, 1997;

L'Aéronavale en 1940, Icare review # 60 and 61, 1972 ;  

Aéronavale - 1915-1954, by Captain Albert Vuilliez, Amiot-Dumont,1955}

Immediately after the World War I, the French Navy preferred the large flying boats (as also the large bomber aircrafts) because they were equally suited to long flights over the sea while watching against German U-Boats.  

A lot of work had been done about the dive bombing by Paul Teste at the beginning of the twenties.

Nevertheless, the French Navy was reluctant about such a technical advance which may endangered the program launched by Georges Leygues, the French minister of Marine.

The reference of sea warfare, actually, was the British Navy and, if the RAF was not interested by the dive bombing, this bombing method was currently used by the Navy.

Some French seamen, individually, understood how efficient could be such a bombing method to destroy ships!

They perfectly knew that a battleship firing at 25 km was able to have, in the best conditions, all her shells in a circle having a radius of at least 150 m.

Such an accuracy was not obtained by the artillery of the more recent French battleships (Dunkerque, Strasbourg, Richelieu and Jean-Bart) using their quadruple turrets, owing to the reciprocal influences of the blasts affecting the shell ejected by the too tightly placed guns at each salvo.

For them, the circle of uncertainty was 300 m in radius, larger than the latest battleships

This huge shortcoming of the French Battleships was fixed only after WW II, in 1948 (too late...), simply by adding a 0.06 second delay between the 1-3 gun couple firing and the 2-4 gun couple firing (a very similar problem was experienced by the Zara Italian heavy cruisers).

It was easily understood that a dozen of dive-bombers were able, after a 300 km flight (i.e. less than one hour of flight), to put all their bombs in a circle having a radius of only 50 m.

Such an accuracy was sufficient to disable most of the Battleships, leaving them as sitting duck for the torpedoes of destroyer or submarines.

That was particularly relevant, because the armored decks of the recent battleships were only half as thick (150 mm) as their armored belt (300 mm). So, they were vulnerable to 250 kg bombs.

A program specifically dedicated to dive bombers embarked on air carrier was published in 1932 by the French Navy.

First sketchs

The first dive-bomber dedicated to the aircraft-carrier Béarn was the Gourdou-Leseurre 430. 

The GL 430 was a parasol aircraft with some similarities to the GL 351 fighter.

She was powered by a 480 hp 9 cylinder radial air-cooled engine Gnome & Rhône Jupiter.

The maiden flight of this bomber was done at the end of 1931. After a lot of work, it finally appears that her top speed – 280 kph – was considered not sufficient.

Some derivatives of this aircraft were built but, as a result of the personal conflicts inside the staff of the company, none were successful.

At the end of 1933, engineer Pillon, engineer in the staff the Nieuport company, conceived a completely new design fulfilling both missions of fighter and of dive-bomber.

The aircraft was a single engined, two-seat, monocoque of all metal construction, with a low inverted gull wing, an enclosed cockpit and a fixed spatted landing gear.

The chosen engine was the Hispano-Suiza 12 cylinder in-line liquid cooled 12 Xcrs of 690 hp.

The Nieuport 140 had a 14 m wingspan and her wing area was close to 27 m², with an aspect ratio of 7.045.

Her fuselage was 9.56 m long and and the take off weight was 2,475 kg.

So, the wing loading was only 92 kg/m², allowing a good maneuverability.

{Parenthesis: The Germans having be bombed in spring of 1940 by the Loire-Nieuport 401 - developed after the Nieuport 140 -were very surprised by her silhouette strikingly similar to the one of the Junkers 87 Stuka.

They accused engineer Pillon to had obtained some data by espionage.

But, because the Nieuport 140 was in flying trials at the beginning of the construction of the first Ju 87 prototype, the French bomber was clearly anterior. 

And the lay out of this aircraft was much more advanced than the one of the Junkers 47.

The first flight occurred in March 1935.

Nieuport 140 – some good ideas wasted…

The top speed were 335 kph at altitude and 290 kph at sea level and the climbing time to 4,000 m was 8' 30", these performances being only average for the times.

The flying qualities were good, including the dives, so it was decided to begin dive bombing.

The dive brakes consisted in 2 mobile fairings rotating from 90° around the struts linking the highest part of the fuselage to the wings. When the pilot was facing the target at the good altitude, flying at rather low speed (150 kph), he had trigger the rotation of these dive brakes to reduce the diving speed.

The first diving trial being successful, a new step was open at July 8th, 1935: The launch of a bomb during the dive.

After diving vertically from 5 000 m to 1 000 m in 26 seconds – this giving an average speed of 154 m/s (554 kph), suggesting a very faster terminal speed, just before the pull-out – René Paulhan, the well known pilot, released normally the bomb and pull up the stick at full throttle.

Unexpectedly, the engine stay silent and the trajectory remaining horizontal. After several unsuccessful attempt to make the engine running, at this very moment, the pilot became aware the cockpit canopy exit was too small to allow him to bail out!

The Nieuport 140 was too far from the coast to avoid a ditch on the sea. Fortunately, Paulhan ditched successfully and was rescued by a speed boat with minor injuries.

The cause of the engine collapse was the use of a fixed-pitch air-screw, which allowed an over speed well above the rated limit.

A second prototype flew in November 1935. After successful trials, she was transferred to Marignane in February 1936 to resume dive flights.
The May 15, 1936, the pilot Jean Decaux, after the release of the bomb, was unable to pull-out and perished in the Mediterranean Sea. No error was found in the technical data to explain this crash.
So, the Nieuport 140 was abandoned.
{Parenthesis: In all the countries where dive bombing were managed, several fatal crash occurred for various reasons, some might be linked to very high speed, other to problems with the air-screw or to the engine (as above), other to an excessive will of accuracy from the pilots.

In Germany, the first prototype of the Junkers Ju 87 Stuka dive bomber fatally crashed on January 24, 1936, killing the entire crew. 

On July 27, 1936, Ernst Udet crashed the Heinkel He 118 dive bomber but was able to bail out.  

In the USA, the prototype of the Chance-Vought Vindicator crashed the August 20, 1936, owing a spin triggered by a slow speed stall at low altitude, killing her crew.}

Toward the war

Two years after this lethal and never explained crash, in June 1938, a new fighter-bomber, the Loire-Nieuport LN 40, dedicated for the use at sea on aircrafts-carriers (the Béarn for a first time and the Joffre and Painlevé scheduled for 1940-41) take off for the first time.

The new aircraft was a single-seater to save weight for the aircraft and room in the aircraft-carriers.

Two other embarked fighter-bombers were built in the same times: The British Blackburn Skua and the Japanese Aichi D3A1 (Val in the US code).

The French aircraft employed the Nieuport 161 fuselage and a new wing with the inverted gull layout of the Nieuport 140 one and the high aspect-ratio close to the one of the Nieuport 161 (7.92).

The landing gear was retractable in two large fairings. 

The empty weight was 2135 kg and the take off weight was 2825 kg.

The wing were more tapered than in the N 140 and had an area of 24.75 m², giving a wing loading of 114 kg/m². 

LN 411 – The silhouette of a fighter, a canon firing trough the air-screw and a bubble cockpit canopy

The LN 40 #2 pre-series demonstrated a top speed of 367 kph measured at 4 700 m and 307 kph at sea level.

In fighting mission, the series LN 401 or 411 were flying at 380 kph at 4 700 m and 320 kph at sea level.

With a training bomb (necessarily out-board), the top speed was 365 kph.

The cruise speeds were 340 kph (80 % of the maximum power) or 250 kph (45% of the maximum power).

The anti-submarine watch missions were flown at 155 kph…

The maximum range was 800 km in bombing mission and 1200 km in CAP, signifying a combat radius of 350 km.

One might be disappointed by the choice of the French Navy to use of the 690 hp Hispano-Suiza 12 X engine (already manufactured in the French naval dockyards since the ordering of the Loire 130 flying boat, instead of the more powerful 860 hp HS 12 Y 31.

With this later engine, the LN 40 could fly faster and carry a heavier bomb, at the expense of 100 km of range…

The Admiral Louis Cassé, who flew a lot with the LN 401, in order to write her book of flying instructions, gave her a top speed of 375 kph.

As a fighter, the LN 401 climbed to 3 500 m in 7’ and to 4 000 m in 8’ 30", at an instant speed of 8 mps, far better than that of the more powerful Skua.

The service ceilings was 9 500 m.

Flying qualities

The Loire-Nieuport 401, better streamlined than the Nieuport 140, was very easy to fly and extremely maneuverable.

She had absolutely no problem during dives.

After unsuccessful trial with splitting dive brakes on the rudder, a simple and good idea was, the use of the extension of the undercarriage to play the same role.

One modification was the addition of 2 vertical fins to the tail to fix a minor stability problem in dive.

In a letter published (page #124) by the review Flight International the August 28th, 1941, a French former fighter pilot of the Béarn carrier wrote these interesting comments :
I was in one of the fighter squadrons of the Bearn (during the war based at Calais) and flew the Loire 40 several times. 

It was very easy to pilot and made very good aileron turns during the dive

The triple tail had been added to the original design to prevent vibrations


It was said that the rudder was a bit insufficient at 90 kph.
An amazing criticism, taking into account the landing speed of no less than 105 kph!

{The same criticism had been already expressed against the Nieuport 161 fighter and was opposed to the last aircraft of these family, the Loire-Nieuport 42.}

The take off was done in less than 150 m and the landing in about 200 m, these values being perfectly compatible with the take off and landing on the old Béarn carrier.

{Parenthesis: As said previously, the LN 40 family was derived from the former Nieuport 161 fighter, by far the best French fighter prototype flying in 1936

All these aircrafts shared the same cooling device.

The Loire-Nieuport 40x experienced easy landing and take off on the Béarn aircraft carrier.

Such an experiment proved the reliability of the lifting capability of the wings. 

One could write: Carrier proven.

But it was also proven in combats during dog fight with Bf 109, as also at the end of the numerous dives they experienced at war.

Industrial production

Three variants have been ordered. 

The two firsts were ordered by the French Navy, the third was lately ordered by the Armée de l’Air after the impressive operational demonstrations of the German Ju 87 Stukas during the Spanish Civil War.
  • The Loire-Nieuport 40 was the first one and was an order of pre-series to test carefully the naval tactics as well as the reliability of the aircraft in operational conditions.
  • The Loire-Nieuport 401, was dedicated to the use on board of an aircraft carrier. So, she was fitted with folding wings, water-tightness devices and also an arrester hook.
  • The French Air force ordered 40 Loire-Nieuport 411, differing from the previous variants by eliminating the folding wing capacity and the arrester hook, obviously, but, also replacing the 2 excellent belt fed Darne Mle 33 of riffle caliber (each firing 600 cartridges) by 2 MAC 34 drum fed machine guns of same caliber (heavier, four times more expensive and firing only 300 cartridges each...).

The pre-series fighter-bombers were produced by the nationalized SNCAO company (which replaced Loire-Nieuport) just one half-year after the order.

Some authors seeming disappointed by a so-called slow production, it’s necessary to underline that CAO was involved in the production of at least two other aircrafts, the Morane-Saulnier 406 fighter and the LéO 451 bomber, both being tagged as having an absolute priority… 

Each of these 2 others aircrafts being very, very time consumers (16,000 hours (officially, but I suspect a building time of more than 22,000 hours, the time needed for the very better Italian MC 200) for the MS 406, 60,000 hours for the LéO 451).

Nevertheless, the order was given at the end of 1938, the pre-series LN 40 were flown in July 1939 and the first series aircrafts at the end of 1939. That was three times faster than the Morane 406! (May be, the construction process was a little too fast, according to criticisms expressed some years after the Battle of France.) 

According to the work of Arnaud Prudhomme, 71 of these fighter-bombers have been delivered at the time of the 1940 Armistice.

General Vuillemin, chief of staff of the Armée de l’Air refused his 40 LN 411, given them to the French Navy.

A little mystery

Amazingly, the last two variants shared a quite absolute weight similarity.

The naval variant had the arrester hook (60 kg) and a folding device for the wings, all things absent from the terrestrial variant.

So, one could expect the Navy LN 401 to be 150 kg heavier than the terrestrial LN 411.

However, the published data are as follows.

For the LN 401:
  • An empty weight of 2,100 to 2,135 kg,
  • A take off weight of 2,750 to 2,825 kg.

For the LN 411
  • An empty weight of 2,100 to 2,240 kg,
  • A take off weight of 2,850 to 2,930 kg.
The 2 empty weights were quite identical (likely for fighter missions). 

But, whatever the mission, the terrestrial LN 411 had always a take-off weight 100 kg heavier than her naval sister!

Bombs and related equipment

Both aircrafts Loire-Nieuport 401 and Loire-Nieuport 411 shared the same bombs.

The G2 bomb which weighted 75 kg, derived from a 155 mm naval shell.

The I2 bomb, derived from a 203 mm naval shell, weighted 150 kg.

These bombs were carried beneath the fuselage and were released by a crutch allowing to avoid the propeller.

Some authors wrote than the Loire-Nieuport 40 were completely unprotected. This legend was introduced to protect the deciders, unable to use these aircrafts wisely.

The pilot seat was armored by a sheet of 5 mm thick of steel, as all the French fighters.

One may regret the windshield was not protected, but, in May 1940, such protection was only a project but on the Bloch 155 series. The armored windshields began to be fitted in Germany and Great Britain after the fall of France.

One also may read that the fuel tank was unprotected against fire. I will give you further the proof it was protected in one of the following sections where I analyze the war operations.

Amazing climbing times

These data published by Arnaud Prudhomme in his book were identical in fighter or in bomber configuration. 
 Altitude                      time                               last 500 m times                             
   500 m   -------->        1' 05"                                        1' 05"
1,000 m   -------->        2' 13"                                        1' 08"
1,500 m   -------->        3' 24"                                        1' 11"
2,000 m   -------->        4' 30"                                        1' 06"
2,500 m   -------->        5' 30"                                        1' 00"
3,000 m   -------->        6' 31"                                        1' 01"
3,500 m   -------->        7' 03"                                        0' 32"
4,000 m   -------->        8' 34"                                        1' 31"
4,500 m   -------->        9' 36"                                        1' 02"
5,000 m   -------->      10' 40" 

(The time to 5,000 m was reconstituted by adding the average time for a 500 m climb to the highest known previous measurement)                                

The average time for each 500 m step was 64".

But the 32" needed between 3,000 m and 3,500 m, is an amazingly fast time, as the 91" between 3,500 m and 4,000 m, is amazingly long, looking as a slow down used to fix an overheating of the engine. 

If it was the case, one may wonder why the measurement was not re-started.

At War

The Netherlands trap

On the May 10, the German diversionary consisted in an offensive against the Netherlands.

This maneuver went perfectly well: British and French generals (and politicians) fell in the trap

The British, because they never accepted to see a country as powerful as was the Nazi Reich having two efficient and performing seaports just facing their own country: Hitler acted as a matador waving the red rag at a bull.

The French wanted, overall, to conserve their last allied, the British.

General Maurice Gamelin has been made General in Chief of Allied Forces out of the blue, may be after having accepted to defend Antwerp at all costs.

Absolutely convinced to have inherited, himself, from an above-than-average intellect, he persuaded General Giraud to send troops in the Walcheren Island, which allow, if necessary, the blockade of the Antwerp trading.

Personnal document of the author: While the German main maneuver followed the red arrows, the French deciders were obsessed by the German presence inside the yellow dotted circles (Walcheren being the South most and Amsterdam being the North most). The British launched some Battle sur Maastricht with six Hurricane as a generous protection...

Obviously these French troopers went by waterways and were to return the same way.

Unfortunately, following this excellent website, they were not well trained, they have light armament, and, overall, their top chief, General Durand, was poorly competent and highly contemptuous… 

So the relationships with the Dutch officers were not suited for a good coordination between allied!

The other French general, Deslaurens, would have been the right man in the right place. 

Unfortunately, when he became the coordinator of the Allied forces, 2 days after the Dutch surrender, most of the initial military assets in the Walcheren stronghold had vanished.

The May 14, the German invaded Walcheren. 

Their offensive was efficient but the deciders thought that an aerial support could be sufficient to deter the Germans to continue! 

So, the French admiral Abrial commanded to the AB2 (First Lieutnant Lorenzi) and AB1 (First Lieutenant Mesny) squadrons to bomb the targets designated in Walcheren.

That was the baptism of fire for the Loire-Nieuport of the AB2 as for the Chance-Vought 156 Vindicator of the AB1 (the only one squadron still equipped with this aircraft, the other one (AB 3) being annihilated in its hangar by the German bombing, the May 10.

Four different missions were completed from the morning of May 15 to late in the night of May 17-18.

The two bomber units were protected by the AC 1 and AC 2 squadrons, both using Potez 631 fighters, under command of CC Jozan. 
  • The May 15, May, a column of artillery was bombed by AB 2 (9 sorties).
  • The May 16, the sluices of the Zuid Beveland canal near Hansweert were bombed by AB 2 (9 sorties) while the AB1 bombed a railway bridge (9 sorties).
  • The May 17 Mai, both AB 1 (10 sorties) AB 2 (8 sorties) take off just before dawn to bomb the road between Walcheren to Zuid Beveland and the armored vehicles travelling on. The Flak appeared very aggressive...
  • A night flight was managed by the two same units at the evening of the same day, starting at 10:30 PM (2 sorties for AB 2, 1 for AB 1).
No loss occurred for the LN 401 among the 27 sorties of the AB 2. 

For the AB 1 squadron, 2 missing Vindicator were reported by Mesny, among the 21 sorties. 

In fact, only one was really missing, the other having landed in Cotentin for some unknown reasons.

The missing Vindicator having disapeared during a night flight, all theories are possible, but an action of the German Night fighters, because they did not exist before the second half of 1941.

So, for a total of 49 sorties, there was only one real loss.

These good results were attributable to several convergent factors.   
  • The German offensive was only a deceptive maneuver. May be, the Flak was not as numerous and aggressive as it demonstrated when protecting the Panzer Divizions.
  • The main part of the German Jagdwaffe, initially protecting the operations in the Netherlands, shifted completely to the French Ardennes at the end of the May 13, for covering the true offensive of general Guderian.
  • The French naval bombers were protected by two squadrons of naval fighters (AC 1 and AC 2) as, also, by a patrol of 3 Curtiss belonging to the Armée de l’Air. So, one Loire-Nieuport 401 downed a Heinkel 111.
  • The AB 1 and the AB 2 were the most experienced.
  • While Admiral Darlan was absolutely ready against an Italian naval attack... which never happened,
  • While French and British Generals were fascinated by the Hitler’s game in Belgium and the Netherlands,
  • General Guderian was attacking at Sedan, the real weakest part in the French defenses.

The Allied high ranking generals were too old to anticipate the speed with which the Panzer Divizionen might progress inside their own lines. 
German generals, since the total defeat they suffered during all the German offensives in 1918, have had the time to perfect the "speed" concept. 

Actually, confronted the German overwhelming advance, the Allied generals remembered that a Military Aviation existed, for which they have been always very avaricious.

Yes, such a strike in the Ardennes could have been efficient if the counter-attack had been simultaneously managed with tanks and dive bombers: The Flak crews would have to choose between different kinds of very dangerous targets. Our losses could decrease and our efficiency get better.

How many training (for similar combined operations) have been done on the topic of how to stop the progression of an army entirely constituted of Panzer Divizionen?  

The answer was absolutely clear: None!

Testimony of a LN 411 pilot in action

Admiral Francis Lainé, then fighter pilot and squadron leader in the 1940 Aéronavale, told us his own perception of the Battle of France in the review Icare # 60, L'Aéronavale, 1st part. 

In November 1939, as first lieutenant and experienced fighter pilot, he chose to lead a Loire-Nieuport squadron, the AB 4. 

But, at Lanvéoc-Poulmic, the airbase theoretically dedicated to the AB 4, only 2 pilots were appointed to his squadron without any aircraft. 

Some "experts", at the Ministère de la Marine, expected seriously the impossibility, for this unit, to be operational before mid-June 1940.

Nevertheless, LV Lainé succeeded to fly 14.5 hours in January 1940, "among them, a magnificent gift of my excellent friend Jean Lorenzi, squadron leader of the AB 2, who allowed me to fly 0 hours 25 and two landings with his own Loire-Nieuport 401."

Succeeding also to transfer the AB 4 to Orly airbase (that was not, actually, a civil airfield), very close to the Nieuport plant of Issy-les-Moulineaux were the LN 411 were manufactured, aircrafts and pilots were operationally ready in April 1940.

The training was done at Cherbourg-Querqueville. It consisted in vertical dives from 4,000 m to 800 m, also in dives at 60° or 45° from 1,200 m to 300 m with concrete bombs then with operational bombs. 

Another training was to fighter missions, with firing operational ammunition.

During the last training, the May 17, a fatal crash of a pilot occurred because, after a perfect hit of the target by his leader, he wanted to release his bomb as accurately, but his LN 411 was too close from the ground to allow him sufficient time to pull up.

The full squadron went to Berck, in order to join the AB 2.

The May 19, both units (AB 2 and AB 4 gathering 20 Loire-Nieuport) received the order to attack German armored columns seen close to Berlaimont.

They took off at 18:30.

It was said that British Hurricanes will escort them to the battlefield. 

For some unknown reason (even today), the British fighters were not at the rendez-vous.

The path chosen to reach the target was strait from Berck to Berlaimont, flying over the town of Arras.

The VIIth Panzer Divizion of Rommel had already started crossing the crossroad and the Vth succeeded thereafter.

May be, both divisions crossed together in the same point, this explaining perfectly the numerous traffic jams seen at the very moment the French attack occurred.

Admiral Lainé reminded: "I was very proud to lead these 20 well armed fighter-bombers to the battle. Indeed, that was the most interesting command I have got during the forty three years I was in the French Navy."

The 2 squadrons flew at rather low altitude in 7 sections, with 100 m between them. The "low altitude" claimed here was certainly not a hedge hopping flight, unsuited for dive-bombers, but a flight at an altitude between 300 m and 600 m. 

So, the top speed of the LN 401 and 411 was reduced to 320 kph and their cruise speed to 250 kph.

During the 20 last kilometers, the Loire-Nieuport dive-bombers were escorted by a "Henschel fighter" (more likely a biplane Hs 123, a very maneuverable biplane assault bomber, and not a parasol Henschel 126, less agile and less armed).

May be, it could have been more wise to curve the path chose more northerly, allowing to fly essentially over Allied territories, obviously unoccupied by the German troops, so the German armored division could had quite no time to prepare their AA guns…

The French formation climbed to 1200 m, at only 10 km of the target.

At 19:30, the squadron leader Lainé dove first, followed by all the wing, exactly over the Berlaimont crossroad. 

He was "warmly welcomed" by an intense AA fire, so much that he believed that 2 of his teammates have been instantly downed.

The Lainé’s Loire-Nieuport was also hit by a Flak shell which destroyed his radio-transmitter.

In fact, if the petty officer Téoulet had been instantly killed by a German shell, his LN 411 flew 20 kilometers more before crashing with his yellow painted bomb still intact (!).

If petty officer Goasguen was downed and killed, that was not at all by the enemy fire, but clearly latter, by friendly fire of the French DCA, just as he was preparing his landing on his airfield.

(So, the French staff created a recognition book to avoid such situation more than one month later, after the ceasefire between France and Germany. Too late…)

Lainé, looking backward, saw the other sections diving tidily and, suddenly, a huge black cloud caused by the smoke of multiple bomb explosions, the Flak fire and by the fire of destructed tanks and buildings. 

The black cloud quickly covered all the town.

A bit latter, Lainé: "I saw a large tank parking, the perfect target for some bombs, which could have done a well-timed massacre, but now, I had no mean to report this to any of my pilots."

Thirty two years latter, remembering his actual mood as he flew Northward at very low altitude, he thought that: "The ideal depicted By Marshall Rommel of a War without Hatred is not available to every performer! ". 

His righteous anger was still present: "To see my teammates downed had made me mad!".

So, he shot at anything that moved: "The gunners of a dreadful Flak 88 mm cannon, and a German biker rolling like a killed rabbit."

Captain Vuilliez wrote all the LN 401 and 411 of this mission escaped from the dive bombing of the Berlaimont crossroad, but the Flak continued along the return, so the losses increased gradually.

At 20:30, four LN 411 of the AB 4 squadron landed at Berck, "all more or less damaged by the Flak fire, but, also, I’m afraid, riddled by fragments issued from the explosions of their own bombs released to late…" (One of the pilots reminded he released his bomb at only 80 m AGL).

This comment is very important when one analyze carefully the losses of the Allied assault bombers.

Nevertheless, very few are the authors who take this fact into account. 

For example, the 50 kg bomb used by the Bréguet 693 - less powerful than the naval bombs - sent lethal fragments on a 150 m radius area around the explosion center.

Among the 5 other LN 411 of this squadron, one was destroyed by French AA fire, one by German Flak close to the attacked crossroad, the three others had belly landed with their pilots alive (2 POW).

For the AB 2 squadron, the petty officer Pascal was killed in flight and crashed close to his target.

Three LN 401 belly landed, their pilots becoming POW.

Only one of the two squadrons, the LN 401 of ensign Faivre, still hit by two Flak 20 mm shells, was attacked by four German Bf 109 E. 

Evading most of the shots, the French pilot succeeded to land in a crude field South of Cambrai and to exited his aircraft unharmed, a brilliant demonstration of his skill and of the handling qualities of his LN 401.

Among the 11 Loire-Nieuport 401 of the AB 2, six were back at home.

Efficiency of the mission

Six bombs of the AB 4 had hit exactly the crossroad englued by a huge traffic jam.
Arnaud Prudhomme wrote the German armored division, in this attack, suffered 400 casualties (KIA + WIA), a heavy price for such a short moment!

Two full days were needed for reorganizing and repairing this division which was stopped.

Collateral damages occurred, obviously: One wing of a building occupied by a boarding school and a complete city block were in rubble.

French POW and half a dozen of Berlaimont inhabitants lost their life, too.

A new target

The next day, May 20, all the available dive-bombers of the 3 squadrons AB 1 (completely equipped with 11 Chance-Vought 156 Vindicator), AB 2 and AB 4 (with only 3 Loire-Nieuport together, the others being in repairing), were sent for a new mission: The destruction of a bridge at Origny-Sainte-Benoîte (about 40 km South of Berlaimont).

The Vindicator of AB 1 took off from a distant airfield (Alprecht), so they had to rendezvous above Berck where stationned the Loire-Nieuport.  

An escort of Hurricane fighters was expected, but, again, it failed to appear. Two hypothesis may be done:

  • The overwhelmed French staff forgot to request these fighters,
  • The British fighters were effectively requested but might be involved in a combat before to be at the scheduled rendez-vous over the French airfields.

Having reached the Berck airfield, the AB 1 squadron flew directly to the Origny Bridge, without waiting the three Loir-Nieuport which were climbing.

It is reported that the engines of these aircrafts being slightly over-heating because the Vindicator were faster, they slow down.

{The American and the French dive-bombers shared the same empty weight of 2135 kg.

The French aircraft carried one 20 mm canon – weighting 60 kg without ammunition – in addition to the 2 machine guns; all these weapons being forward firing.

The American aircraft had only 2 similar forward firing machine guns and the one other being firing aft for the gunner.  

The engine of the Vindicator delivered 825 hp, so it was 20% more powerful than the Hispano-Suiza 12 X of the LN 401, this corresponding for a possible 9.5% gain in speed.

Unfortunately, the American aircraft had a two-blade air-screw optimized to play the role of dive brake, her engine cowling was not well streamlined, her cross section was undoubtedly larger and her wing area too.  

So, I’m not convinced at all the Vindicator was really faster than the Loire-Nieuport.}

The Vindicator, now alone, were attacked by twelve Bf 109 E.

All the gunners were surprised and, their weak armament was not sufficient to protect the bombers and 5 of them were instantly downed, including the 3 section leaders.

Two Vindicator, being crossing a cloud during the Messerschmitt attack, flew to the target and bombed unsuccessfully the bridge. 

The AB 1 squadron leader Mesny returned safely at home but his teammate was downed inside the French lines, his gunner being KIA.

One may deeply regret these missions were managed between 1200 m and 300 m AGL. With doubled missions ceiling could have given quite as good results with much less losses.

Obviously, it would be necessary to experience such situation.

Good or bad aircrafts?

The main criticisms, you can read about the Loire-Nieuport 401 and 411, are only copy and pasts of the opinion William Green wrote in the 50’s about the so-called "infamous" Junkers 87 Stuka.

There are two alleged "facts" to support his opinion:
  • The losses suffered by the Ju 87 during the Battle of Britain. 
  • Amazingly, the number of downed is 71, to which it is possible, if you want, to add 30 damaged, for about 250 to 300 aircrafts involved in this operation. 
  • Unfortunately, if you compare these losses with the 261 Messerschmitt Bf 110 downed (plus 70 damaged), for an initial amount of the same order of magnitude, you became aware the Junkers 87 was a considerably more difficult target for the British aerial defense than the fighter Bf 110!   
  • The complete withdrawing of this aircraft from the Battle after the end of September 1940, is, very often, seen as a proof of failure of the Ju 87, without refutation by the Germans survivors. 
  • However, the withdrawal of the Ju 87 from the Battle of Britain, currently attributed to her inferiority against Hurricane Mk I and Spitfire Mk I fighters, was, undoubtedly, a very good image for propaganda. 
  • But, the Truth is that Mr. Hitler decided the Babarossa operation at that very moment! So, for such a purpose, the Ju 87 was particularly relevant…
Regarding the so-called heavy losses, the first ideas of the deciders would be
  • What parts of our tactical choices were wrong?
  • What parts of the military training must be modified?
If, and only if, the two previous questions have the null answer, then one may question the relevance of the aircraft chosen.

Criticisms on the LN fighter-bomber family

There were French criticisms issued mainly from deciders who have given their opinion a posteriori without fighting themselves with these aircrafts.

Among them was Jacques Mordal, a Navy medical officer, who was in the staff of admiral Auphan at the end of 1942, at Vichy. Thirty-two years later, he wrote the introduction for the #60 of the Icare review on the Aéronavale en 1940
  • He thought, wrongly, the LN 401 /411 to be 100 kph slower than the Vindicator.
  • Moreover, he wrote the high rate of losses experienced demonstrated that the Loire-Nieuport dive-bomber was not fitted for attacking terrestrial targets…
  • Nevertheless, carelessly, he mentioned that, if Admiral Abrial could easily release a squadron of Vindicator, he wanted obstinately retain his Loire-Nieuport.
  •  Such an information had a clear signification: Abrial relied much more on the Loire-Nieuport 401 and 411 than on the Vindicators, and that was certainly not a lack of confidence about the crews of the Amercan dive bomber.

Negative assessments were also expressed by CC Corfmat, who was one of the first French pilots to fly the Vindicator
  • In his report on the Battle of France, given to Vichy authorities at the end of 1940, he express "the need to replace the obsolete Loire-Nieuport by American aircrafts".
  • He said also the Loire-Nieuport was too frail and worn out. 
    • Such an argument, if very frequently used, was not as fair as it may appear. E.g., the North-American P 51 Mustang was, undoubtedly, the best American fighter to see real air war during the WW II. 
    • Compared to the P 47 Thunderbolt, she was frail, but she was, by far, the better protector for the Allied bombers flying over Germany.
    • Moreover, after the LN being hit by AA fire, a lot of repairing works were only temporary (piece of wood or even of fabric, instead of standard aluminum sheets). If the aircraft had been correctly reconditioned, this criticism would have disappeared.
    • The capture of the entire technical team in Boulogne, due to the complete ignorance of the naval staff about the actual military situation in the vicinity of Dunkirk, was a complete disaster: The good solution could have been to send all the complete aerial units to Le Havre, Rouen or Deauville, or, better, in England. 
    • But, also, the Vichy administration, which was building a collaboration with Hitler's Reich, wanted to explain that the France’s defeat was caused by the numerous deficiencies of the French armament (or of the French soldiers…), instead of the ones of the French Command.

The Loire-Nieuport, a good dive-bomber

Positive assessments were expressed by her pilots who relied on their fighter-bombers.

  • Admiral Louis Cassé, was, actually, a fighter pilot of the AC 1 squadron in 1939. Allotted to define the doctrine of use of the Loire-Nieuport 40 family, he expressed how he was excited while he was flying this fighter-bomber.  
    • He highlighted also that, if the vertical dive bombing was a fantastic military advanced concept, it required an important training for the pilots to obtain safely a good accuracy.  
    • However, he regretted the too slow production of the best fitted bomb sight, suggesting that it explained the very low altitude for the releasing of the bomb, in order to hit perfectly the designed target
    • Moreover, the night flying was very easy with this aircraft.
  • Admiral Lainé, who conducted the successful attack on Berlaimont was also absolutely pleased about his LN 411 (as you may read above). 
    • He  underlined the exceptional visibility offered to the pilots, allowing an exceptional accuracy to the bombing. 
    • After the war, facing a parliamentary commission, he was a bit less laudatory, complaining that after 30 hours of operational missions, the aircrafts were dirty and too easily flammable.  
    • He recopied also the criticisms of Captain Corfmat about the too light construction of the Loire-Nieuport. But, if these aircrafts were so flammable, why most of the remaining LN 401 / 411 did not show any evidence of burning?
  • The petty officer Moulinier conducted, alone, the May 21 at noon, a true fighter mission:
    • He damaged heavily a Dornier 17 bomber (one engine in fire), but was hit by the German rear gunner
    • Then, Moulinier made a successful emergency landing. 
    • Nevertheless, during the afternoon of the same day, he was able to fly his repaired Loire-Nieuport and to land in safety at Cherbourg-Querqueville at 19:15...
    • This action, as also the CAP managed by the AB2 to protect the Calais-Marck airbase, demonstrated the self-confidence of the pilots flying this fighter-bomber.
    • Captain Vuilliez, in his book, after having gathered the testimonies of numerous pilots LN 40, 401 and 411, were laudatory about them.

The operational results of the LN 40x were clearly better than those of the Vindicator:

  • In the Netherlands, the Loire-Nieuport and the Vindicator flew respectively 27 and 21 sorties. In totally similar conditions, for a apparently similar bombing efficiency, none of the LN was missing, one of them even destroying a He 111 bomber... But one Vindicator was lost and another lost her way…
  • In the fighting against the advance of the German armored division toward the sea, the bombing of the Berlaimont crossroad (20 sorties) was successful, for the price of 2 KIA and several POW and 9 LN downed by the Flak and 1 by the French DCA. 
  • At Origny, the AB 1 (11 sorties) suffered 6 Vindicator lost to the German Messerschmitt 109 (3 pilots KIA) and the remaining 5 did not succeed to hit the bridge at Origny. The 3 Loire-Nieuport, among them 2 unused the previous day and one repaired, flew the very same mission, several minutes later, destroyed the bridge at the price of 1 aircraft downed by the Flak (one POW).  

The results suggest the Vindicator was not an accurate bomber and was not as maneuverable as her low wing loading may suggest.

One must add two elements about this unfortunate aircraft:
  • The last delivery of Vindicator was transferred by General Charles De Gaulle to the British government a few hours before he flew to London to create the Free France. It was to avoid to reinforce the military power of the German army. Nevertheless, after training and somes trials, the British airmen refused to use of these aircrafts, preferring to assign the crews to Fairey Swordfish, at least a really reliable aircraft!
  • The only one operational mission where USA used the Vindicator during the Pacific War was the Battle of Midway. Again, these aircrafts suffered huge losses without any hit on the Japanese ships. Maybe, the nicknames found by the USMC crews, "Vibrator" and "Wind indicator", suggest how these aircrafts was unfitted to the dive-bombing.

France had also ordered also the completely obsolete biplane Curtiss Helldiver XSBC-3 and, by pure chance, the Douglas Dauntless which was an absolutely excellent aircraft but, unfortunately, she was not delivered in time for the battle...

Here and there, you may read the LN 401 or 411 were devoid of fireproof fuel tanks. It’s a legend.

I may oppose two arguments:
  • When first lieutenant Lainé flew a CAP the May 21, he attacked a group of 3 German armoured cars but his LN 411 was hit by the return fire of one of them, one bullet piercing her fuel tank. A while later, Lainé saw the fuel flowing and decided to go back at Berck.
After his safe landing, he established the bullet was an incendiary one, which had also pierced his seat and finished its trajectory in his silk parachute which was partialy burned. So, you have the proof the incendiary bullet which consumed the silk was unable to set fire to the fuel tank!
  • My last argument is issued from the German pictures of 8 of the 11 Loire-Nieuport downed at Berlaimont or Origny-Sainte-Benoîte or of the 3 left at Berck owing the lack of spars for repairing. Only one show an aircraft burnt to a cinder.
May be, the tank protection consisted only in a kind of inert gas, e.g. a bottle of CO2.

Toward a better fighter-bomber...

However, the Loire-Nieuport was not perfect. From the beginning, the engineers of the Nieuport design office had very understood their fighter-bomber must have better performances.

At the very moment of the production of the LN 40 begun, they were authorized to follow two ways.

The first way was to fit on the LN 40 a more powerful engine, the first one already available being the Hispano-Suiza 12 Y 31 delivering 860 hp, an excess of power of 25 %, suggesting a top speed at ~ 410 kph.

The LN 402 was built in the summer of 1939 and made her maiden flight the November 18, 1939, late, too late...

After various handling adjustments, this aircraft achieved a top speed 363 kph at 3,700 m and 378 kph at 4,000 m.

This amazing increase of 15 kph for only 300 m suggest an error in one of these records, but the top speed could only be achieved about 700 m higher.

The climbing time to 4000 m was 5' 25" (1' 15" better than the Morane 406 "fighter"!) and the service ceiling was 9,200 m.

One can see, in a picture of the cowling of the LN 402, for the first time, new short rearward exhaust pipes, identical to those of the Arsenal VG 33.

The HS 12 Y 31 having an operational optimal altitude of 4,500 m, the best speed could have been 25 kph faster.

Why they did not use of the more efficient exhaust pipes of the Dewoitine 520?

The second way, which was followed simultaneously to the first one, was to modify some part of the LN 40 toward a more aerodynamic aircraft with, eventually, an even more powerful engine, in order to obtain a very faster aircraft.

So, in this new Loire-Nieuport 42, the wings had an area reduced to 21 m², the inverted gull wings of the Nieuport 140 were abandoned, their geometry becoming very similar to that of the Nieuport 161 fighter.

A prototype of was ordered in September 1939 with, theoretically, a Hispano-Suiza 12 Y 51 delivering 1,100 hp for take off and 1,000 hp at altitude.

The landing gear, very different from the one of the LN 40 series, was delivered only in May 1940.

The LN 42 was ready to fly in the 10 days preceding the French surrender and made her maiden flight the June 24 or 25.

It necessary to stop her flights and, in November 1942, to hide her in a Provencal farm.

In 1944, after the Liberation of the South France, the work on the Loire-Nieuport 42 has resumed in the SNCASO facility at Cannes, after an order of the French Navy. 

An arrester hook was fitted. 

But the aircraft was transferred to the SNCAC at Toussus-le-Noble.

The new first flight occurred the 25 August 1945.

After 19 hours in the air during the 3 following months, the LN 42 was sent to the CEV at Marignane for official trials which started the December 7, 1945 and ended the January 11, 1946, after 26 sorties (29 flight hours, a good reliability for a prototype.).

The Loire-Nieuport 42 had an empty weight of 2,325 kg and a take off weight of 3,105 kg (with bomb).

  • These trials were successful (Source: Prototypes de l’aviation Française, 1945-1960, by JC Fayer, E-T-A-I, 2002): 
    • The LN 42 demonstrated an excellent maneuverability. 
    • Her top speed exceeded 462 kph at 4,700 m, 435 kph at 3,500 m and 400 kph at seat level.
    • The cruise speed was 375 kph. 
    • Her stall speed varied from 90 to 110 kph (determined by the configuration) and remaining always under control.
    • The landing speed was 122 kph. 
    • The total range exceeded 1,000 km. 
    • However, it was said that, at slow speed, the rudder acted rather weakly and a heavy buffeting appeared. That was seen as unacceptable for aircraft carrier service. Interestingly, the same criticisms have been made 7 years earlier about the LN 401, which had made excellent carrier trials…

 LN 42 

With a 50 kg bomb, after taking off at 2900 kg (940 l of fuel), the LN 42 climbed to 3,500 m in 5 minutes and, at that altitude, had a cruise speed of 310 kph and a top speed of 350 kph.

For the bombing, the dive was easy, with a very good stability. 

The standard procedure started at 4,100 m at a speed of 155 kph. The dive ended at 900 by a pull up hemi-circle with a radius of 200 m with 2.7 g.

Undoubtedly, the last Loire-Nieuport dive-bomber could have been an excellent fighter-bomber from the last months of 1940 to the end of the WW II. 

In 1946, the French Navy had no more aircraft carrier and the French deciders favored the ordering of jet planes, a rather wise decision.

On the other hand, irrationally, the LN 42 was also perceived as a remnant of the 1940 defeat.

However, the French Air Force was unaware of the multiple problems it had to solve in the French colonial empire, especially in Indochina, so, the LN 42 was abandoned to several experiments and decommissioned at the end of 1947.

Instead, France used of the advanced fighter trainers Morane-Saulnier 472 and 475 which had many problems about their handling qualities. 

They were a slower (420 to 440 kph) and lacked accuracy in ground attack.

A hint of the Charge of the Light Brigade... 

When the French staff launched aerial attacks on the German armored columns, it acted as inconsiderately as acted the British top General who was in charge of the British troops at the Battle of Balaklava, in Crimea (1854).

There were 4 similar "ingredients" in these two costly attacks:
  • The use of a very powerful unit, expected wrongly as able to disrupt a significant part of the enemy forces.
  • The very bad information about the enemy defensive system, unfortunately, the Armée de l'Air seem not to have shared its knowledge to the Aéronavale immediately after the attack of German mechanized column by its Bréguet 693 at Tonger, the May 12, 1940

    • Ok, the Lieutenant Delattre (the real leader who had created this procedure to attack the Panzers with the Bréguet) have been downed (after a second flyover on the target...) and killed. 
    • But the leader of the other squadron, who attacked with a complete surprise, was unharmed. So, he could gave precious informations about the German structure of anti-aircraft defense to his colleagues of the Navy. 
    • One could also have expected similar information from the British pilots of the Fairey Battle involved in the attack of German column in Belgium, but the British deciders seemed not aware of that problem until the Battle of Britain. 
    • All the Allied pilots had largely paid these absences of information with their blood...
  • The isolation of the attacking units from any supporting units,
  • The very long time needed to the transmission of the orders, which prohibit any surprise attack before the deployment of the Flak.

In the Berlaimont case, one may add the complete absence of training of the naval pilots about ground targets, a somewhat odd situation, knowing the important role of the French marine troopers, even in the WW I (at Dixmude, for example). 

So, these pilots wanted an extreme accuracy (in order to sink a boat) which was not as important usually when they had to attack armored divisions which are scattered on a (comparatively) huge area. 

Another problem of training

Since the apparition of the first French naval dive-bombers, it would be very useful to use some of them to accustom the French infantrymen to some simulated attack by these aircraft. 

To my knowledge, only the French colonel Eugène Barthélémy, who was in command of a machine guns unit at Chartres, asked such a training at the end of 1939, during the Phoney War. 

First Lieutenant Pierre Habert, test pilot for the SNCAO, was chosen for this mission which was done in January 1940, apparently in the tail end of a depression.

He dove vertically from a little cloud, using of a perfect surprise.
  • One part of the soldiers, totally unprepared, have not seen the aircraft at all.
  • Most of the men, only used to fire at horizontally flying aircraft (or, even, on aircraft preparing their landing, a stupid training explaining perfectly the numerous friendly fire suffered by the Armée de l'Air).
  • Some soldiers, nevertheless, behaved perfectly, shooting (virtually) on the target.

If such an experiment have been generalized in the French Army, the French troops were much more dangerous for the Stukas as for the German tanks. Accordingly, the German losses could have increased significantly...

But the French deciders preferred to develop theaters shows...


The French Air Force ordered the Loire-Nieuport 411, but reject them when they were built.

The French Navy ordered 25 Loire-Nieuport 401, demonstrated they were absolutely suitable for aircraft carrier operations, but dismissed its only one carrier, the Béarn, for bad reasons. They would have been very interesting in Norway (as their British homologous, the Skuas...).

In war operation, these aircrafts demonstrated excellent flying capabilities and outstanding maneuverability. They were very controllable in dive and had a good accuracy of bombing. 

Yes, their losses were relatively heavy.

After the defeat, someone complained about a too light construction, but the real cause of the losses were not related to the aircrafts, they were due to several huge weakness in the decider's minds.
  • The attacks were never made at the arrival of the enemy troops in a given place, so, a dozen hours later, the enemy AA fire was perfectly ready to defend their position.
  • None of the attacks were done at the right place in a right time. The bombing in Zeeland were misplaced, they could be much more efficient in the morning of the May 13 between Bouillon and Sedan.

P.S. : I choose to not write above the brief clash with the Italian, because the Loire-Nieuport units had lost a lot of aeronautical technicians (POW), the half of their aircrafts and they were not used against significant targets.  

2 commentaires:

  1. C'est Lainé lui-meme qui a dit que " les réservoirs n'étaient pas protégés ni auto-obturants" , voir légende page 78 Icare no. 60

    1. Le petit encarté de l'amiral Lainé a quelques problèmes. Il attribue au LN 401 une vitesse de pointe de 250 km/h ! En fait, il reprend les critiques de Corfmat.
      Mais lui, il est rentré à sa base après que son réservoir ait été perforé par une balle incendiaire qui a carbonisé la soie de son parachute. Peut-être croyait-il à une protection divine.

      Je ne suis pas sûr que les pilotes de 1940 avaient une bonne connaissance de l'"anatomie" de leurs avions, et en particulier, de leurs réservoirs. En général, mécaniciens et pilotes étaient bien peu miscibles à l'époque...

      Le fait qu'un seul avion ait brûlé ne permet pas une telle conclusion, le contre-exemple étant le Mitsubishi A6M2 qui brûlait bien.