Nieuport 161 - A Stronger French Air Force in May 1940

[DMZ]

Dec 5, 2021 18:20:28 GMT miletus12 said:

M.S.405=> 406 => 410 => 411/412, Finnish Morgo-Morane. The P-40 went from B to J and was still not as good as a Wildcat in the air to air role, but still was good enough, just as the Hurricane was good enough for most of the war. The LN 161 like the P-38 was full of unforeseen problems that would have taken years to iron out.

No, LN 161 would have been delivered to GCs at least six months before the MS 406 was. Why? Because Morane-Saulnier had the smalest industrial assets of the time with few machines and staff, was unable to industrialize its prototype, most of the MS 406 were produced in Bougenais plant that belonged to a join-venture between Breguet and Loire-Nieuport...

As already said, Loire-Nieuport (then SNCAO) was able to deliver LN 401 in twelve months after the order using the same Bouguenais plant where MS 406 and LeO 451 was buit at the same time with the highest priority.

We are not talking about a plane comming afterward to replace another already in production. MS 406 and LN 161 was on the same starting line but the later was denied to start.

Anyway, MS 406 has been replaced in GCs by H-75, MB 151-2-5 and D.520; this shows how it was perceived in AdA.

Dec 5, 2021 18:20:28 GMT miletus12 said:

There is a point in these articles where AdA generals are asking French army generals for missions and the army generals shrug their shoulders and say "I have no work for you!" What kind of ground pounder in charge tells his aerial eyes that he has no work for them? Insane is what that situation is. Were the French army generals that out of touch with reality?

Unfortunatly, even reported with some exaggeration (there was, of course, requests from Army to Air Force), this was more or less how several high rank officers in Army was concieving Air force.

Dec 5, 2021 18:20:28 GMT miletus12 said:

4. On top of that, having an efficient monoengine fighter could have leaded to a familly of fighter-bomber, photo-reco plane... that would also have changed a lot of things.

There was already the Potez 63 series. How was it used? Not too well.

Po 63 familly was not so bad, despite underpowered, PO 637 then 63.11 made a good job in difficult conditions and reported the Ardennes offensive.

Marcel Bloch did keep its design office and developped it after nationalization. All the planes designed was giving him royalties, he made much more money with it than in the previous years, the same for Louis Breguet. I have to check but I think Felix Amiot and Henri Potez played similar game without the same success.

A5M Claude was designed in same time as the LN 161 (six month earlier, not enought to have been known in France), it is said in Wikipedia (French) that Jirō Horikoshi decided to take inspiration from Dewoitine all metal fighters.

[miletus12]

Dec 5, 2021 20:08:42 GMT DMZ said:

No, LN 161 would have been delivered to GCs at least six months before the MS 406 was. Why? Because Morane-Saulnier had the smalest industrial assets of the time with few machines and staff, was unable to industrialize its prototype, most of the MS 406 were produced in Bougenais plant that belonged to a join-venture between Breguet and Loire-Nieuport...

That goes to industrial policy. Ever hear of an outfit called Brewster Aircraft?

The solution was to nationalize the sorry outfit, jail the management and draft the labor union leadership into the infantry and put the left behinds to work making Corsairs. I think some stern measures for the Morane Saulnier outfit. Come to think of it, Renault could have used some stiff rectification?

As already said, Loire-Nieuport (then SNCAO) was able to deliver LN 401 in twelve months after the order using the same Bouguenais plant where MS 406 and LeO 451 was buit at the same time with the highest priority.

Naval Aircraft Factory. When Curtiss screwed up, they were in the hip pocket with aircraft to replace the planes the USN needed that Curtiss could not deliver.

The point is that the M.S.406 was in the pipeline and should have been pushed along with the unready LN161. Numbers matter.

We are not talking about a plane comming afterward to replace another already in production. MS 406 and LN 161 was on the same starting line but the later was denied to start.

Much like the XB38? Politics (Army / Navy) kill more good ideas than any "military logic". In the case of the LN161 as in the XB-38 I bet it was the engine, that was the excuse and service rancor that was the real reason.

Anyway, MS 406 has been replaced in GCs by H-75, MB 151-2-5 and D.520; this shows how it was perceived in AdA.

Order of battle.

I see some GCs equipped with Morane Saulniers, more than a few.

[DMZ]

Dec 6, 2021 21:33:39 GMT miletus12 said:

The point is that the M.S.406 was in the pipeline and should have been pushed along with the unready LN161. Numbers matter.

OK, Let's go back to the historical timeline:

Jul 3, 1934 - C1 program for a mono-engine fighter
Aug 9, 1935 - MS 405 first flight
Oct 5, 1935 - LN 160 first flight
End 1936 - MS 405: less than 400 km/h, LN 160: 440 km/h
Feb 20, 1936 - MS 405 enter CEMA (Centre d'Essai des Matériels Aéronautique) for official tests, still nearly 400 km/h
Mar 1936 - LN 161 first flight
May 9, 1936 - LN 161 enter CEMA for official tests, 476 km/h
Jun 1936 - 15 MS 405 ordered
Sep 1936 - 30 LN 161 order ready, won't be send after Cazaux accident on Sep 22.

As you can see, there is only three months between the two aircraft and MS 405 was far from being ready. It's not like MS 405 was on production and outnumbered LN 161's one.

Jan 4, 1937 - Minister of Air announced : "Due to unacceptable delays in delivery, the Minister decided to requisition the MS plant." Morane-Saulnier replied: "These aircrafts have to be delivered by July 1937." It is said in the newspaper that SNCAO will be in charge of the mass production of MS 405.
Mar 1937 - First serie batch of MS 406 ordered
Feb 3, 1938 - MS 405 first delivery (obviously not July 1937!)
May 1938 - End of pre-serie production, start of serie MS 406 deliveries

So it took 20 months to deliver the first MS 405 from the initial order and 14 months for serie delivery! Nothing in the pipeline.

On the other side:

Second half 1937 - LN 40 dive bomber (evolution of LN 140) prototype ordered
Jul 6, 1938 - LN 40 first flight
Late 1938 - 6 pre-serie LN 40 ordered
Feb 1939 - 36 serie LN 401 ordered
Mid 1939 - 40 serie LN 411 ordered (for AdA)
Jul 1939 - 4 pre-serie LN 40 delivered
Sep 1939 - LN 401 mass production first deliveries

So it took roughly 12 months for serie delivery from order (the pre-serie order date is unclear and not reliable).

ITTL

As LN 40-401 was more complex than LN 161 (dive-bomber with arestor hook, folding wings) and Bouguenais plant where LN 40x was produced was already used for MS 406 and LéO 451 production, one can assume it won't have taken more to 12 months from LN 161 order to delivery, meaning first pre-serie LN 161 would have been delivered on September 1937, five months before MS 405.
Even in the worst case assuming it took 18 months, both fighters would have been delivered at the same time.

My statement is to said that, without changing anything else that ordering LN 161 pre-serie on September 1936 despite Cazaux accident, LN 161 would have been in greater numbers in May 1940 and would have matched even Bf 109E. No more, no less. I don't see in your arguments anything that could refute my point.

"Numbers matter"! 

The outcome of the battle is something else and your documents about the huge negligence of the high command of the French Army and AdA in particular show that it would have been difficult to do much better.

[DMZ]

Dec 6, 2021 21:33:39 GMT miletus12 said:

Anyway, MS 406 has been replaced in GCs by H-75, MB 151-2-5 and D.520; this shows how it was perceived in AdA.

Order of battle.

I see some GCs equipped with Morane Saulniers, more than a few.

The process was ongoing and not yet finished on May 1940.

Just before or during Battle of France:
III/2 > H-75
I/3 > D.520
II/3 > D.520
III/3 > D.520
II/6 > MB 152-155
III/6 > D.520
II/7 > D.520

Remaining on MS 406 in metropolitan France at the end of June 1940:
III/1
I/2
II/2
I/6
III/7
Plus two in FNA (III/5, I/9) and one in Lebanon (I/7).

[miletus12]

To keep this simple.

Dec 7, 2021 7:36:38 GMT DMZ said:

Jul 3, 1934 - C1 program for a mono-engine fighter
Aug 9, 1935 - MS 405 first flight
Oct 5, 1935 - LN 160 first flight
End 1936 - MS 405: less than 400 km/h, LN 160: 440 km/h
Feb 20, 1936 - MS 405 enter CEMA (Centre d'Essai des Matériels Aéronautique) for official tests, still nearly 400 km/h
Mar 1936 - LN 161 first flight
May 9, 1936 - LN 161 enter CEMA for official tests, 476 km/h
Jun 1936 - 15 MS 405 ordered
Sep 1936 - 30 LN 161 order ready, won't be send after Cazaux accident on Sep 22.

As you can see, there is only three months between the two aircraft and MS 405 was far from being ready. It's not like MS 405 was on production and outnumbered LN 161's one.

The situation is that one has two competing prototypes, one of each iteration.

One crashed and one did not. That "fact" is significant to a procurement committee for aircraft, no matter what the nation or time. Military experts are conservative. If something flies and does not crash during testing, they will prefer that plane to one that does crash. Especially if the crashed prototype is found after investigation to have crashed from a design fault. This was the case in the LN161. it was not pilot error as was proved in the case of the P-38 which was a problem plane but which did not crash because of a design flaw.

Dec 7, 2021 7:36:38 GMT DMZ said:

Second half 1937 - LN 40 dive bomber (evolution of LN 140) prototype ordered
Jul 6, 1938 - LN 40 first flight
Late 1938 - 6 pre-serie LN 40 ordered
Feb 1939 - 36 serie LN 401 ordered
Mid 1939 - 40 serie LN 411 ordered (for AdA)
Jul 1939 - 4 pre-serie LN 40 delivered
Sep 1939 - LN 401 mass production first deliveries

So it took roughly 12 months for serie delivery from order (the pre-serie order date is unclear and not reliable).

I look at that record and I ask, why make the LN40 a dive bomber? And I look at the derivative changes to the LN161 to produce the LN40?

It turns out that the LN40 was more of the Nieuport line of N140 than the LN161. Again we have the stall drop opposite wing and the tail control issues with this bird.

Looking at the sparse details of the LN161 as reported here, I am still convinced that the plane was down selected by the committee because they felt it had mechanical issues and the need was for a plane that could fly today and not after a two year gestation period.

Plus I have to read this dubious article and seriously question some of the underlying assumptions and claims for the aircraft.

May I quote?

Mysterious top speeds, performances

The only published performances are those of the prototype #02.

Those of the 01, which flew very earlier, from September 1935 until September 22, 1936, have never been published, this being clearly disturbing for me.

These two prototypes were fitted with the same kind of engine, an Hispano-Suiza 12 Ycrs providing 860 Cv at 3250 m.

Her speeds at different altitudes were:
400 kph, at sea level,
416 kph at 1,000 m,
435 kph at 2,000 m,
456 kph at 3,000 m,
478 kph at 4,000 m (the highest published speed, but see below),
474 kph at 5,000 m,
470 kph at 6,000 m,
458 kph at 7,000 m,
443 kph at 8 000 m,
426 kph at 9,000 m,
400 kph at 10,000 m,
360 kph at 11,000 m.
All these data were published in the paper of A. Prudhomme in Air Magazine #25, April 2005.

Nevertheless, the highest speed you read above cannot be the true top speed.

Why?

Because the engine providing its maximum output at 3,150 m, the top speed must be reached ~1,300 m higher, at about 4,500 m, owing to the dynamic pressure created by the speed of the aircraft, and, also, the much lower temperature of the air, which allowed a better filling of the cylinders.

Knowing that, at such altitude, any 100 m gain of altitude give ~2 kph increase of speed until the dynamic rated altitude.
So, the top speed of the Nieuport 161 might be more than 490 kph between 4,500 and 4,700 m (488 kph for 4,500 m, 490 kph for 4,600 m, 492 kph for 4,700 m, and so on).

Such a speed, obtained without rearward exhaust pipes, was exactly of the same order of magnitude than the top speed of the Hurricane prototype K 5083, which used an engine delivering 1,030 hp.
If one had fitted exhaust pipes on the Nieuport, you must have an extra speed of 15 kph...

In the Arnaud Prudhomme's paper, in the table summarizing the numerical data of this fighter, he wrote also a maximum speed of 496 kph (very close to my preceding estimation), without any explanation about the altitude or the identification of the prototype. It seems to be a "surviving" measure obtained by the Ni 161-01 prototype.

You may think the air intakes of the compressor suffered from some misconception, inducing a weaker engine power output, then you must explain why the best instantaneous climbing speed (13.6 m/s) measured by the test pilot was found just at the same 4000 m level...

{The Hurricane K 5083 obtained her top speed of 315 mph at 16,500 ft and her top instantaneous climb speed at only 6,500 ft (the engine was a Merlin C of 1,029 hp at 11,000 ft:
www.wwiiaircraftperformance.org/hurricane/k5083.html).}



The economical cruising speed of the Nieuport 161 was 350 kph, ~30 kph faster than the Morane 406.

The maximum cruising speed was 426 kph, given by a Russian site.
This speed is consistent with a top speed of 495 kph at altitude.

Such values demonstrated that how easily the Nieuport 161 could fulfill the escort duties of both the recce Potez 63 or the bomber LéO 451, both being too fast for the Morane "fighters".

From the other hand, the climbing speed was impressive:
1,000 m in 1' 16",
2,000 m in 2' 30" (the last 1,000 m in 1' 14"),
3,000 m in 3' 44" (the last 1,000 m in 1' 14")
4,000 m en 4' 58" (the last 1,000 m in 1' 14")
5,000 m en 6' 17" (the last 1,000 m in 1' 19")
6,000 m in 7' 50", (the last 1,000 m in 1' 32")
7,000 m in 9' 41" (the last 1,000 m in 1' 52")
8,000 m in 12' 03" (the last 1,000 m in 2' 22") (A time 3 minutes faster than the time specified for the French contest, a climbing ability clearly better than the Bf 109 E of 1940!)
9,000 m in 15' 19" (the last 1,000 m in 3' 16")
10,000 m in 20' 30".
11,000 m, her service ceiling, were reached in 34' 50".
Her absolute was 11,250 m,

As a matter of comparison, the time needed for the Spitfire Mk I K 9793, fitted with a similar kind of air-screw, was 29 minutes to reach 32,000 ft (~9,730 m).

This fighter exceeded, by far, the performances of all the other contenders for the French contest.


An bizarre weight problem

The first published data (in the 60's) were an empty weight of 1,748 kg and a take off weight of 2,278 kg, allowing a wing loading of 151.8 kg/m² and a power loading of 2.65 kg/m².

In the Arnaud Prudhomme work, you can reed some amazing data regarding both empty and take off weight. He gives us an empty weight of 1,915 kg.

The discrepancy between his data and the numerous older ones are amazing.

From the other hand, a direct derivative of the Nieuport 161 was ordered as a fighter bomber by the French Navy in 1938: The Loire-Nieuport 401.

The main change was a completely new wing of 24.75 m² in W (a 2/3 increase of wing area), an arrest hook, a weaker engine, a bomb launch device, a much more robust undercarriage, a folding device for the wings.

All this help me to evaluate the weight increase to at least 400 kg.

So, I prefer to conserve the first published data.



The fighter absolutely needed by the Armée de l'Air


All these performances were very promising, taking into account the early level of development of the Nieuport 161.

In gun trials, it was told she was an excellent gun plate form.

No surprisingly, a 30 fighters order was about to be sent in mid-September 1936.

Sixty years later, William Green wrote: "the LN 161 showed considerable promise and was the favored contender for the Armée de l'Air order..."


Unfortunately for the French Armée de l'Air and her pilots, the Nieuport 161 was written off in a crash - caused by irrelevant instructions - occurring during firing trial in dive at low altitude, lethal for the engineer test pilot.

I will come back to this crash, for which the official explanations are absolutely unlikely, in this post, because its consequences were absolutely dramatic for French Army at the beginning of the WWII

In this other post, I'm explaining the numerous assets of the Nieuport 161 fighter over the Morane 406.

In this last post, I'll show first the dishonest engine policy of the CEMA as also the different policies for the taking into account of the crash of the 2 main contenders, leading to chose the Morane 406, a slow fighter having very poor speed and climbing performances.


My blog in French is entitled "L'Aviation selon Drix"

Air pressure and temperature, outside ambient, does not work that way. Also, if MTOW dry and wet is off by 15% how can one judge performance?

[DMZ]

Dec 7, 2021 15:38:34 GMT miletus12 said:

The situation is that one has two competing prototypes, one of each iteration.

One crashed and one did not. That "fact" is significant to a procurement committee for aircraft, no matter what the nation or time.

Both crashed killing their pilot... And AdA ordered Martin DB-7 despite a crash in front of French officials during tests...

And even if LN 161 had to be abandonned due to technical problems, ordering a fighter that acheived none of the requirement (top speed, climbing rate, ceiling, range) is a fault that no nation can afford!

Dec 7, 2021 15:38:34 GMT miletus12 said:

I am still convinced that the plane was down selected by the committee because they felt it had mechaident to the Ministernical issues and the need was for a plane that could fly today and not after a two year gestation period.

I am still convinced that Pierre Bonte was lying when explaining radiator exhausts was the cause of the stall.

I already explained why it was a lie and the root cause is elswhere, probably human error as stated in the telegram annoncing the accident:
- The message informing the minister of the accident specifies: "the accident does not seem to be attributable to the material", not an evidence but to be considered;
- In April 1938, Stéphane Thouvenot, member of the Air Minister staff, wrote: "The accident seems to have been caused by a loss of speed near the ground following a dive and a stall climb";
- The dive-bomber Loire-Nieuport LN 40-401-411 had the same radiators and was used in operational configurations that were far more challenging than those of the LN 161 (dive-bombing, landing on carrier) without any accident despite being heavier (2,835 kg vs. 2,278 kg fully loaded) with a smaller engine (Hispano-Suiza 12X 690 hp); there is even a photo showing an LN 40 on final approach on the carrier Béarn with one of the wing flaps extended (on the left) and the other not, without apparently causing the slightest problem of stability;
- Michel Detroyat stated in January 1938, during the discussions intended to choose a complementary aircraft to the MS 406: "There is no possible comparison between them [LN 161 and MB 151]: because of its ease of piloting, the Nieuport 161 is the only aircraft likely to be entrusted to the majority of military pilots";
- Despite intensive test in wind tunnel following the crash, the radiators did not evolve on the subsenquent prototypes of the LN 161 whereas this was the case for many other aircraft, including the MS 405-406 and the D.520; the simple fact of moving the outlets from the upper to the lower surface of the wing would have eliminated the problem if such was the case, modifications which are extremely easy to carry out and do not modify the structure of the wing.

Remember lots of people (Col. Delaittre, head of CEMA, ingénieur-général Mazer, Gen. Vuillemin) lied in official meetings (Comité du Matériel) in this particular case.

I know Drix blog, it was there I discovered the fabulous Nieuport 161. But I don't agree with his conclusions, I commented his post in French accordingly.

Genealogy
LN 140 => LN 40 (wings refined, retractable undercarriage, airbrake) => LN 401 => LN 402 (engine 12Y) => LN 42 (new wings)
LN 40 => LN 160 (derivative of the fuselage) => LN 161 (engine 12Y)

[miletus12]

Dec 7, 2021 21:08:49 GMT DMZ said:

And even if LN 161 had to be abandonned due to technical problems, ordering a fighter that acheived none of the requirement (top speed, climbing rate, ceiling, range) is a fault that no nation can afford!

Brewster F2A.

Dec 7, 2021 21:08:49 GMT DMZ said:

I am still convinced that Pierre Bonte was lying when explaining radiator exhausts was the cause of the stall.

Probably not lying but speculation. I know the Americans had trouble with the Hawks and radiator inlets unsticking boundary air on the wing chord and that was published. This was an actual wind tunnel verified issue with the early Lightning as well. But as for the LN161, something had to disturb that upper wing surface flow and create an unstick condition leading to the wing drop.

The Havoc crash was pilot error and not a perceived mechanical.

[DMZ]

So, if I understand well, you are comfortable with the choice of a fighter that respond to none of the required performances. Is it correct?

And you accept Bonte post war explanation although official statement was the plane was not involved.

The Havoc fatal crash was on single engine trial. Not human error as far as I know.

[miletus12]

Dec 8, 2021 18:40:58 GMT DMZ said:

So, if I understand well, you are comfortable with the choice of a fighter that respond to none of the required performances. Is it correct?

And you accept Bonte post war explanation although official statement was the plane was not involved.

The Havoc fatal crash was on single engine trial. Not human error as far as I know.

1. I am never comfortable with a choice that indicates the specifications were not properly thought out.
2. I simply am not going to call someone a liar merely because he might be speculatively mistaken. We have no conclusive documentation or paper trail to state an absolute conclusion of fact. Err on the side of uncertainty. This is not a case when Jimmy Work of Brewster Aircraft hired known felons and broke the law himself to build defective aircraft.
3. It was pilot error. The pilot evaluating failed to read the Martin flight manual properly and set the flaps and trim tabs incorrectly.
 

[DMZ]

Dec 9, 2021 1:41:20 GMT miletus12 said:

1. I am never comfortable with a choice that indicates the specifications were not properly thought out.

OK, so based on the result on the 1935 competition MS 405 sould never have been ordered in production, LN 161 should have. Thank you.

Dec 9, 2021 1:41:20 GMT miletus12 said:

2. I simply am not going to call someone a liar merely because he might be speculatively mistaken. We have no conclusive documentation or paper trail to state an absolute conclusion of fact.

The point here is as late as April 1938 you don't have any document, official or not, saying LN 161 was involved in accident, on the contrary. Bonte statement is post war in his book. So, based on this, is there any reason why LN 161 should not been ordered in 1936?

Dec 9, 2021 1:41:20 GMT miletus12 said:

3. It was pilot error. The pilot evaluating failed to read the Martin flight manual properly and set the flaps and trim tabs incorrectly.

So my mistake. Thanks for precision.

[miletus12]

Dec 9, 2021 3:25:14 GMT DMZ said:

OK, so based on the result on the 1935 competition MS 405 sould never have been ordered in production, LN 161 should have. Thank you.

Hmm.



I do not see the leap of faith here. When a set of specifications is listed as design objectives to be met, manufacturers and designers try to meet the goals specified within the means available to them. To cite the LN161 as an example: the design basis for the C1 requirement was for a plane;



link

The actual criteria were, at least, five:
A sufficient speed to catch as quickly as possible the bombers actually in development everywhere;
A climbing speed enabling to shot down any spy plane flying higher than 8,000 m before she goes home with her precious informations;
At least one capacity allowing to break the combat to save the precious pilot's life when necessary (e.g. when the fighter has no more ammunition);
A cockpit enabling the pilot to have the better possible situation awareness;
A general layout allowing a fast mass construction.

This is frankly an incompetent technical specification. (^^^)

The details of what was wanted should have been spelled out as hard numbers of performance required.

a. 550 km/hour minimum desired IAS at 6000 meters in level flight.
b. absolute service ceiling of 9,000 meters.
c. Rate of climb from sea-level to 5,000 meters in 300 seconds.
d. overboost for military power of 30% for 300 seconds. Baseline performance metric is 750 kW with measured torque of 500 nw to the air screw.
e. airscrew thrust efficiency at least 70%
f. pilot visibility forward 240 degrees and down each side 120 degrees. Rear view mirror.
g. wide splay landing gear, either tricycle or tail drag configuration, all retractable with flush hoods.
h. gun / cannon armament, mixed with sufficient mass to destroy any existent or predicted bomber. Suggested mass throw is 1/2 kg per second. Suggested armament is 1 or 2 motor cannons, and 2 or 4 rifle caliber machine guns. 
i. Must be plumbed for either a 250 kg bomb or 475 liter expendable carry tank of aviation gas.
k. Must be modular in assemblage with fuselage barrel, main wing spar and engine /supercharger /cooling circuit modules as separate assemblies that can be joined together if required at first echelon maintenance units. Sufficient spare sub-assemblies must be part of the manufacture run to allow 2 complete rebuilds of damaged aircraft.
l. power assisted controls are desired, but force balanced manual input controls may be substituted.
m. Corner turn at 45 degrees bank must not exceed 300 meters in radius.
n. automatic fuel / air ratio sets for supercharger and carburetor air at intake 2,000, 4000, and 8,000 meters altitude is desired. 
o. An engine tear down and rebuild of no less than 100 hours between such evolutions is required.
p. pilot familiarization and solo competency must be demonstrated within 50 hours of air flying experience with the aircraft. 

That is a USAAF specification (converted to metrics for most of us) for 1936. The result was the P-38 Lightning which exceeded most of those specifications despite an inferior American technology to French or British aeronautical capability at the time.

The point here is as late as April 1938 you don't have any document, official or not, saying LN 161 was involved in accident, on the contrary. Bonte statement is post war in his book. So, based on this, is there any reason why LN 161 should not been ordered in 1936?

It crashed. That is public record. As I wrote, we have little documentation as to why. One cannot call a person a liar without some proof.

  


           

[DMZ]

You can find the technical specifications on this page of Drix blog

Summary of the French fighter program (July 1934)

Main requirements:
A totally enclosed cockpit (imposed).
A radio-emitter/receiver (imposed).
A retractable landing-gear (heavily suggested).
A comprehensive sight on the enemy aircrafts was expected during combats.
The maximal speed must absolutely exceed 450 kph,
The climbing time to 4,000 m was to be better than 6 minutes,
to 8,000 m 15 minutes,
to 10,000 m 20 minutes.
A total range of at least 2 hours 30' at 320 kph (800 km) or 3 hours 30' at 230 kph (805 km).

And here are the performances of the prototypes and serie:

Oct 23, 2021 22:50:48 GMT DMZ said:

What was the actual performance of the two competitors?

	C1 Requirement	MS 405	LN 161	MS 405	LN 161	MS 406 (1)
year	1935	1936	1936	1937	1938	1939
max speed (km/h)	450	433	478	443 (2)	496	457 to 465
max speed (mph)	280	269	297	275	308	284 to 289
ceiling (m)	11,500		11,250		11,250	9,300
ceiling (feet)	37.730		36,900		36,900	31,170
climb to 4.000 m	6min		4min58s		4min29s	6min28s to 6min46s
climb to 7.000 m				19min
climb to 8.000 m	15min		11min05s		10min51s	16min32s to 18min10s
range (km)	825		875	650		800 (3)
range (miles)	513		544	404		497

It should be noted that the maximum speed of the MS-406, with the radiator raised, could not be maintained for more than a few minutes (2 minutes according to the testimonies of the pilots of the time) under penalty of burning out the engine. The maximum speed of the LN 161, on the other hand, was continuous.

(1) Official rejection values for serial aircraft. The values vary according to the type of mounted propeller.

(2) The top speed of 480 km/h or sometimes 486 km/h (298 or 302 mph) could be found in various newspapers of this era but does not appear in any official documents.
See Pierre-Yves Hénin's blog (in french):
sam40.fr/le-morane-406-des-handicaps-connus-des-performances-occultees/

(3) With additionnal fuel tank on top of the main one that slowed down the filling.

As you can see, LN 161 reached and exceeded all required performances (minus 250 m on ceiling...) in 1936, MS 405 none. Even in 1939, MS 406 barelly achieved two out of four (max speed and range) and was far below for ceiling and climbing rate.

Do you still consider MS 405 order was right?

Dec 9, 2021 15:37:43 GMT miletus12 said:

The point here is as late as April 1938 you don't have any document, official or not, saying LN 161 was involved in accident, on the contrary. Bonte statement is post war in his book. So, based on this, is there any reason why LN 161 should not been ordered in 1936?

It crashed. That is public record. As I wrote, we have little documentation as to why. One cannot call a person a liar without some proof.

So he DB-7 crashed, so the MS 405 crashed...

You don't answer the question. As the LN 161 was not held responsible for the accident until as late as April 1938, is there any reason why not ordering it in September 1936?

If a fatal accident is a reason why whatever the cause, DB-7 should never have been ordered and MS 405 order should have been canceled.

[miletus12]

Dec 9, 2021 16:52:49 GMT DMZ said:

As the LN 161 was not held responsible for the accident until as late as April 1938, is there any reason why not ordering it in September 1936?

As I remarked above, it was suspected that the LN161 had a design flaw due to the unexplained observed stall drop of one wing when the wreckage was examined. I cannot explain, due to insufficient documentation, why it took two years for the speculation that it was the radiators which was the cause for the stall and drop. Maybe, it was a longer than usual accident cause elimination process and a search for similar incidents? When the Havoc crashed, it was instantly visually obvious that the flaps and the trim tabs had been miss-set, and it was pilot error that contributed to the plane's fall out of control when he simulated one engine out conditions.

It cannot be more clear what the differences were in the two examples.

[miletus12]

Dec 9, 2021 16:52:49 GMT DMZ said:

Main requirements:
A totally enclosed cockpit (imposed).
A radio-emitter/receiver (imposed).
A retractable landing-gear (heavily suggested).
A comprehensive sight on the enemy aircrafts was expected during combats.
The maximal speed must absolutely exceed 450 kph,
The climbing time to 4,000 m was to be better than 6 minutes,
to 8,000 m 15 minutes,
to 10,000 m 20 minutes.
A total range of at least 2 hours 30' at 320 kph (800 km) or 3 hours 30' at 230 kph (805 km).

Pardon me, but that is still too generalized and incomplete to be considered a competent requirements of performance objectives for a prospective fighter aircraft. I do applaud the time aloft requirement. Many air forces (including the American one) often omitted minimum endurance aloft. This would be an impediment when the enemy could run one out of gasoline and watch one fall without even having to work to splash you very hard.

[DMZ]

Dec 9, 2021 17:09:14 GMT miletus12 said:

As I remarked above, it was suspected that the LN161 had a design flaw due to the unexplained observed stall drop of one wing when the wreckage was examined.

It was suspected, never demonstrated as far as I know.

Dec 9, 2021 17:18:16 GMT miletus12 said:

Jan 9, 53910 8:16:40 GMT @DMZ said:

Main requirements:
A totally enclosed cockpit (imposed).
A radio-emitter/receiver (imposed).
A retractable landing-gear (heavily suggested).
A comprehensive sight on the enemy aircrafts was expected during combats.
The maximal speed must absolutely exceed 450 kph,
The climbing time to 4,000 m was to be better than 6 minutes,
to 8,000 m 15 minutes,
to 10,000 m 20 minutes.
A total range of at least 2 hours 30' at 320 kph (800 km) or 3 hours 30' at 230 kph (805 km).

Pardon me, but that is still too generalized and incomplete to be considered a competent requirements of performance objectives for a prospective fighter aircraft.

Why did you omit:

Dec 9, 2021 16:52:49 GMT DMZ said:

Summary of the French fighter program (July 1934)

Main requirements:

It's obviously not the exaustive quote of the C1 program, Drix just emphasized on the main requirements, out of these max speed, ceiling, climbing rate and range.

And you still not answer my questions. So I assume you have no objection on the fact that MS 406 should have been elimated in regard of its poor performances, lower than expected. And LN 161 should have been ordered after having complied with all requirements. And in absence of evidence of material cause, LN 161 order should have been issued as planned.