# Dewoitone 520 question



## Jerry W. Loper (Mar 26, 2012)

If France had not been knocked out in 1940 and lasted a few years, did the Dewoitone 520 have the development potential to stay competitive with top European fighters like the Spitfire and Me-109?


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## tomo pauk (Mar 26, 2012)

With Hispano Suiza 12Z fitted (from 1300-1500 HP) it should've been a competitive fighter. Even with latest 12Y (1100 HP) it looks good. The D.520 was about as small as Bf-109, or Soviet Yaks.


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## Tante Ju (Mar 26, 2012)

I have not seen specs for 520.. imho a very interesting and beutiful aircraft with great potential. Too bad it was never given a chance. Some features like supercharger and engine cannon were very forward for its time. Though I read it was not a very forgiving aircraft, and had violent spins.


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## davebender (Mar 26, 2012)

Dewoitine D.520 - Wikipedia, the free encyclopedia
“It was a nasty little brute. Looked beautiful but didn’t fly beautifully. Once you get it on the ground, I was told not to leave the controls until it was in the hangar and the engine stopped. You could be taxiing toward the hangar and sit back when suddenly it would go in a right angle.” 

It's possible the problems could have been fixed but that's a pretty damning evaluation from a highly regarded test pilot.


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## Jenisch (Mar 26, 2012)

It would be interesting to see the opinions of French pilots.


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## TheMustangRider (Mar 26, 2012)

I had always a particular interest for this fighter as well given the fact that it was not allowed to evolved technically as its main counterparts did throughout the war.
Does anyone has statistics on how well they performed against the Luftwaffe during the Battle of France?


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## JoeB (Mar 27, 2012)

TheMustangRider said:


> I had always a particular interest for this fighter as well given the fact that it was not allowed to evolved technically as its main counterparts did throughout the war.
> Does anyone has statistics on how well they performed against the Luftwaffe during the Battle of France?


Counting individual cases in "Battle of France-Then and Now", D520's shot down 14 Bf109E's for loss of 30 D520's to Bf109E's, about the same kill ratio as Hurricane v 109 in BoF, .5:1, a bit worse than the Hawk 75 (.6:1), but considerably better than the older generation French fighters (Ms406, Bloch etc which went around .3:1 v the Bf109E).

Vichy D520's in Syria downed 2 Tomahawks for 3 losses, 4 Hurricanes for 2 losses, 3 Fulmars w/o loss, but lost 4 to Gladiators with no victories. One D520 and a Fulmar were downed off North Africa in May '42. In 'Torch' over Algeria Sea Hurricanes and Seafires downed 3 D520's w/o loss and USAAF Spitfires downed 3 with one loss; over Morocco USN F4F's may have accounted for the disappearance of an Aeronavale D520; the F4F's other opponents were H75's though they mistakenly claimed some D520's in other actions where none were airborne.

It's the pilot not just the plane, tactical and operational situations differ, D520's had greater success v non fighters (though hardly any WWII fighter *wasn't* successful v non-fighters)...all the usual caveats. 

Joe


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## TheMustangRider (Mar 27, 2012)

Thanks for the information Joe, much appreciated.

As you correctly point out, in most cases it is the pilot and not just the plane; it is my opinion that the Dewoitone D.520 had the capability to remain competitive a few more years into the war.


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## zoomar (Mar 27, 2012)

My gut feeling is the the D-520 did not have the development potential of either the Bf-109 or Spit, in spite of the fact that it was conceptually similar. That said, I do believe the 520 would have given a good account of itself in 1940-41 if the collapse of France had not occurred as quickly as it did. 

One reason I doubt the development potenial of the plane is the D-521. This D-520 modified to take the Merlin engine was by all reports worse than the original.


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## Jenisch (Mar 27, 2012)

I'm not surprise with this. If the plane was already a problem normally, imaginate with all the add weight of a Merlin.


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## tomo pauk (Mar 27, 2012)

Japanese not only imagined, but installed 1500 HP in a Zero.


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## Shortround6 (Mar 27, 2012)

Some planes accepted larger engines with more grace than other planes did. 

Planes that were nice handling planes or easy to fly had more "room" for things to to get worse before the handling got to "evil".

Planes that were marginal in handling qualities never seemed to get better with more power.


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## tomo pauk (Mar 27, 2012)

The heavier and more powerful engine would require airframe adjustments, no doubt about that. Before we proceed talking about how D.520 behaved, perhaps we should read the experiences of the regular users (French, Italians, Bulgarians), and look for the accidents vs. flying hours ratio. 


BTW, Jenisch, why have you edited the post #10 in this thread?


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## Jenisch (Mar 27, 2012)

tomo pauk said:


> The heavier and more powerful engine would require airframe adjustments, no doubt about that. Before we proceed talking about how D.520 behaved, perhaps we should read the experiences of the regular users (French, Italians, Bulgarians), and look for the accidents vs. flying hours ratio.
> 
> 
> BTW, Jenisch, why have you edited the post #10 in this thread?


 
I have noticed the error of my comparison. I didn't see you post after.


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## eagledad (Mar 27, 2012)

Hello!

I have collected the following data on the De 520:

First check out Kurfurst’s Messerschmitt 109 Page, (at Kurfurst.org a great source for 109 data IMHO) specifically

Kurfürst - CEAM : Rapport sur l'avion Messerschmidt 109

Secondly, in trolling the net I found the following chart:











My God Fly your wing always!

Eagledad


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## yulzari (Mar 28, 2012)

The Bulgarians had no special affection for the type but I don't recall being told of losing many to ground accidents. Then again it was a professional highly trained (if poorly equipped) force designed to meet a threat from Romania or Turkey, not UK/US forces. The Germans sold them to the Bulgarians in lieu of more Me109s, which was what the Royal Bulgarian Air Force really wanted, as the Bulgarians pointed out that they had nothing other than a few Me109s that could seriously bring down a modern Allied bomber so Bulgaria was a open door into central europe. At least the D520 had a 20mm cannon (or 1/4 the firepower of a late MkII Hurricane!) Has to be better than a PZL24 or Avia for air defence. I suspect they were paid for in tobacco.


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## tomo pauk (Mar 28, 2012)

Are there any French or Italian experiences with the D.520 available on-line?

Hi, Eagledad, 
what were the differences between the different D.520s; the speed difference is some 40 km/h?


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## eagledad (Mar 28, 2012)

Hello Tomo Pauk!

D 520 no 3 was a standard early production aircraft that would have been found during the Battle of France. D 520 No 465 had a HS 12Y49 motor compared to no3's HS 12Y45, a revised front cowling (more streamlined), and "jet" exhaust stacks. My understanding is that No 465 is more representative of late production D520s, and would have appeared late in 1941.

May God fly your wing!

Eagledad


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## FLYBOYJ (Mar 28, 2012)

Interesting thread guys! One comment on Eric Brown's comments - I'd like to know what other pilots thought about the 520 in the air. Brown was very biased and for this most part his assessment of the aircraft's handling on the ground could be said about 3/4 of the fighters produced during WW2. Could Brown's opinions be based on the fact that some have said the 520 was comparable to early Spitfire marks? BTW Werner Molders was shot down by one during the battle of France.


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## tomo pauk (Mar 28, 2012)

That is what it's all about - we need reports from real users, in order to draw conclusion.

Hi, Eagledad,
Could you please point me to a source that covers different modifications of the D.520?


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## eagledad (Mar 28, 2012)

Hello Tomo Pauk!

More sources for the 2 different D 520’s are Profile Publication Number 135, The Dewoitine 520, page 13, and French Fighters of World War II in Action, Aircraft number 180, page 43.

By the way, the profile publication shows that D 520’s during the Battle of France: 


Aircraft Destroyed Probable	
Bf-109E 23 10
Bf-110 9 1
Do 17/215 24 16	
He 111 16 8
Hs 126 12 1
Ju 87 14 3
Ju 88 2 0	
Hs 123 1 0
Cr 42 4 0
Br 20 3 0


The cost was placed at 85 D 520’s, only 54 due to direct enemy action, with 40 pilots killed, wounded or made prisoner, and 4 additional pilots killed or wounded in accidents.

The above data is somewhat different than Joe B’s. I make no claim that this data is better or worse than his data. Please be aware however, that this data is from a 1966 publication, so if Joe’s information is newer it may well be more accurate.

Hello Flyboy!

I do not have any information on how a D 520 would compare to a Spit Mk I or II. All I have is Eric Brown’s impressions of the D 520 vs a Seafire IIC. As you might expect, he felt that the Seafire was superior in all aspects except rate of climb.


May God fly your wing!

Eagledad


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## FLYBOYJ (Mar 28, 2012)

eagledad said:


> Hello Flyboy!
> 
> I do not have any information on how a D 520 would compare to a Spit Mk I or II. All I have is Eric Brown’s impressions of the D 520 vs a Seafire IIC. As you might expect, *he felt that the Seafire was superior in all aspects except rate of climb*.


 Imagine that! Thanks for the info!


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## JoeB (Mar 28, 2012)

eagledad said:


> More sources for the 2 different D 520’s are Profile Publication Number 135, The Dewoitine 520, page 13, and French Fighters of World War II in Action, Aircraft number 180, page 43.
> 
> By the way, the profile publication shows that D 520’s during the Battle of France:
> 
> ...


The book I quoted from ("The Battle of France-Then and Now") is much newer (it came out in the last few years) but I think the bigger difference is that this book researched the fates of individual a/c in both sides' records. Whereas, I would assume the number in the book you quoted is what the French pilots claimed at the time, especially due to the category 'probable'. If the D520 pilots claimed 23 Bf109's destroyed plus 10 probable, but actually destroyed 14, that would be a quite plausible rate of over claim, probably more accurate claiming than the whole WWII average of all air arms.

Joe


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## Vincenzo (Mar 28, 2012)

eagledad i think your info are for french claims, in "Battle of France-Then and Now" the losses are real losses crosschecked french and germans report


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## eagledad (Mar 28, 2012)

Hello Joe B and Vincenzo!

As I wrote, I have no quarrel with your figures. The 1966 data may well be just from French records available at that time, and would not include any examination of German data. Thank you for your responses! 

Just one more bit of info, a Curtiss Hawk 75A did a 360 degree turn in 12 seconds, a D 520 in 15 seconds and a MS 406 in 18 seconds. Unfortunately, the altitude of the test is unknown.

May God fly your wing!

Eagledad


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## yulzari (Mar 30, 2012)

Just a gentle word of warning. 

Captain Eric Melrose Brown, CBE, DSC, AFC, MA, Hon FRAeS, RN used to be quoted as a word form God. Now some seem to assume everything he wrote was biased. He was as human as any of us and his opinions were based upon his experiences to date and, of course, coloured by them as ours would be. Do you know an American who thinks the P51 is rubbish, a Briton who thinks the Spitfire was a waste of time or a German who thinks an Me109 was an overengined lightweight?.

Nevertheless he was hugely experienced and respected as a man, as a pilot generally and as a test pilot in particular, by his peers *who knew better than us*. His notes should be taken as a genuine reflection of the aeroplanes he flew, as he found them, on the day. Equally we should be careful not to therefore assume that individual aeroplane X he flew was identical to all types of aeroplane X. Only that the individual aeroplane X he flew actually performed as he found on that day.


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## FLYBOYJ (Mar 30, 2012)

yulzari said:


> Just a gentle word of warning.
> 
> Captain Eric Melrose Brown, CBE, DSC, AFC, MA, Hon FRAeS, RN used to be quoted as a word form God. Now some seem to assume everything he wrote was biased. He was as human as any of us and his opinions were based upon his experiences to date and, of course, coloured by them as ours would be. Do you know an American who thinks the P51 is rubbish, a Briton who thinks the Spitfire was a waste of time or a German who thinks an Me109 was an overengined lightweight?.
> 
> Nevertheless he was hugely experienced and respected as a man, as a pilot generally and as a test pilot in particular, by his peers who knew better than us. *His notes should be taken as a genuine reflection of the aeroplanes he flew as he found them on the day*. Equally we should be careful not to therefore assume that individual aeroplane X he flew was identical to all types of aeroplane X. Only that the individual aeroplane X he flew actually performed as he found on that day.



And right there answers the feeling about Brown. he indeed was a very talented test pilot and engineer, but much of his gospel was based on inital flights.


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## tomo pauk (Apr 1, 2012)

eagledad said:


> Hello Tomo Pauk!
> 
> D 520 no 3 was a standard early production aircraft that would have been found during the Battle of France. D 520 No 465 had a HS 12Y49 motor compared to no3's HS 12Y45, a revised front cowling (more streamlined), and "jet" exhaust stacks. My understanding is that No 465 is more representative of late production D520s, and would have appeared late in 1941.
> 
> ...



I've took a look at what the No.465 had improved over BoF Do.520s, from the 'French fighters in action'). It includes addition of boundary layer 'trap' (separator?) for the coolant radiator, individual exhaust stacks, replacement of the oil cooler by a heat exchanger (but it does not explain how was that accomplished). The changes were made in late 1941, so it remains unclear whether such improvements would've been made in late 1940, for service in 1941 (providing France is undefeated by then). Such improvements, along with installment of the latest 1100 HP 12Y engines (let alone the 12Z engines), would've made the D.520 a potent warbird for 1941. Alas, it wasn't meant to be.


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## Altea (May 13, 2012)

Hello



eagledad said:


> View attachment 197374



The number N° 13 had better speed (549 km/hin fact) at 700 m higher than the N°2, because of better designed duct inlets, leading to dynamic pressure improvement.

I'd rather quote the D-520 airframe: exept some teething troubles (with engine oil cooling), it was competitive in overall performance against Me-109 despite its weaker hispano engine (885-910 hp vs 1050 at height).

I have some doubts about quick developpement of Hispano Suiza engines.Y-31 and 45 were running on 85 octanes fuel, the 1000 hp Y-51 used 100 octanes fuel, thant mean massive imports from USA and GB. 
Soviet M-105 engines were running on 91-92 octanes one. Maybe M-103? But once again it's 950-960 hp at best, no much progress...
Probably the best immediate solution was a french kind of Yak-1/Yak-3, Hellcat/Beracat transition from the D-520 to the D-551.
Dewoitine D-551 - Chasseur - Un sicle d'aviation franaise, les avions franais

Regards


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## GregP (May 13, 2012)

Poor ground handling is usually ther esult of the landing gear being too far forward or not aligned correctly. Either one is easy to fix. Moving the gear is not easy on an existing airframe, but is relatively simple when you build a new one.

The D.520's performance was not tip top, but it was in the category of the Me 109E.

In my opinion, all the faults could have been corrected and it could have been a good fighter. The development may or may not have had wonderful potential, but the D-520 could have been fixed into a pretty decent fighter. I don;t know if it had CG issues, good or poor roll, or much aboutit, I once flew an RC model of it and it flew as well as anything else RC I ever flew. That's no proof of anything, but the outline was pretty scale and it could have been made to fly well.


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## Shortround6 (May 13, 2012)

The D-551 offered speed but in other ways it might be seen as retrograde. Smaller wing means higher wing loading, higher landing speed and larger turning circle. Retractable landing *SKID* means better streamlining and performance, what is does for ground handling??? View from cockpit is also a bit suspect.







For another view

Flashback on glorious planes


I am not as confidant that just sticking 100 octane fuel in the tank would have lead to big increases in power. Did the Hispano have the strength to stand up to the higher pressures in the cylinders without failing? Didn't the Russians narrow the bores a couple of mm and add weight? Poorer materials or engine wasn't strong enough?


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## pinsog (May 13, 2012)

yulzari said:


> Just a gentle word of warning.
> 
> Captain Eric Melrose Brown, CBE, DSC, AFC, MA, Hon FRAeS, RN used to be quoted as a word form God. Now some seem to assume everything he wrote was biased. He was as human as any of us and his opinions were based upon his experiences to date and, of course, coloured by them as ours would be. Do you know an American who thinks the P51 is rubbish, a Briton who thinks the Spitfire was a waste of time or a German who thinks an Me109 was an overengined lightweight?.
> 
> Nevertheless he was hugely experienced and respected as a man, as a pilot generally and as a test pilot in particular, by his peers *who knew better than us*. His notes should be taken as a genuine reflection of the aeroplanes he flew, as he found them, on the day. Equally we should be careful not to therefore assume that individual aeroplane X he flew was identical to all types of aeroplane X. Only that the individual aeroplane X he flew actually performed as he found on that day.



I understand what you are saying and as a general rule I would agree with you, but I have to wonder what Mr. Brown was smoking when he rated the Fairey Swordfish as a better torpedo bomber then the Grumman Avenger. Englishman or not, I doubt there is another person on the planet that would arrive at that conclusion.


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## GregP (May 13, 2012)

The link above suggests the tendency to turn when on the ground was due to lack of a tailwheel locking device ... and ity was corrected in later models.

The link also suggest the D.20 had good roll and general manruverability, suggesting it would have been a pretty decent pick for a front line fighter of the day.

I find it hard to believe that the D.520 was a complete dog, and think that, although I really like Eric Brown, perhaps he was writing about a fighter with horrible ground handling that would have been and WAS easily correctable, but pretty decent flight manners.


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## Siegfried (May 14, 2012)

pinsog said:


> I understand what you are saying and as a general rule I would agree with you, but I have to wonder what Mr. Brown was smoking when he rated the Fairey Swordfish as a better torpedo bomber then the Grumman Avenger. Englishman or not, I doubt there is another person on the planet that would arrive at that conclusion.



I believe in terms of tonage sunk the Fairy Swordfish was the most succesfull torpedo bomber of the war, so there is an objective basis for this. The aircrafts abillity to fly slow and to fly low and attack at night seemed to be its winning card. I've looked long and hard at why the Swordfish got through to the Bismark. The Bismarks heavy AAA was at the time the best in the world on a par with the USN Ford range keeper, a fully triaxially stabalised tachymetric synthetic system with remote power control while the medium 3.7cm AAA was also gyro-sta. The bismarks FLAK was based around triaxially stabilised directors and could throw up 60-80rpm while some of the Quad 2.0cm FLAK units were also stabalised. The reality seems to have been the aircrafts low flying abillity and the aircrafts abillity to exploit the bad weather eg hiding behined waves and clouds. Surviving German sailers complained of seeing the aircraft only intermittantly as they approched.

My conclusion is that no navy in the world had the abillity to deal with the Swordfish in those circumsatances at that time nor did many aircraft have abillity to exploit those weaknesses in most ships defenses. A few years latter and everyone has vastly improved their AAA.

Of course the Krisgsmarine never had a chance to finnish its aircraft carriers Graf Zeppelin or Seydlitz so Swordfish were seldim confronted with intercepting fighters.


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## The Basket (May 14, 2012)

However much potential the D520 had, it first flew in October 1938. At least 2 years behind where it should be and inferior to the Spitfire and 109 and marginally better than a hurricane. Not good.

The Fw190 flew only 8 months later. The 520 was old news and marginal news at best. It may have been the best French fighter but 2 years too late.


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## pinsog (May 14, 2012)

Siegfried said:


> I believe in terms of tonage sunk the Fairy Swordfish was the most succesfull torpedo bomber of the war, so there is an objective basis for this. The aircrafts abillity to fly low and to fly low and attack at night seemed to be its winning card. I've looked long and hard at why the Swordfish got through to the Bismark. The Bismarks heavy AAA was at the time the best in the world on a par with the USN Ford range keeper, a fully triaxially stabalised tachymetric synthetic system with remote power control while the medium 3.7cm AAA was also gyro-sta. The bismarks FLAK was based around triaxially stabilised directors and could throw up 60-80rpm while some of the Quad 2.0cm FLAK units were also stabalised. The reality seems to have been the aircrafts low flying abillity and the aircrafts abillity to exploit the bad weather eg hiding behined waves and clouds. Surviving German sailers complained of seeing the aircraft only intermittantly as they approched.
> 
> My conclusion is that no navy in the world had the abillity to deal with the Swordfish in those circumsatances at that time nor did many aircraft have abillity to exploit those weaknesses in most ships defenses. A few years latter and everyone has vastly improved their AAA.
> 
> Of course the Krisgsmarine never had a chance to finnish its aircraft carriers Graf Zeppelin or Seydlitz so Swordfish were seldim confronted with intercepting fighters.



You are making a torpedo runon a ship somewhere in the Pacific Theater, a Zero is moving in to intercept you and you have no fighter escort, or if you do they are busy, would you choose a Swordfish? or an Avenger? The correct answer for everyone on the planet besides Eric Brown is Avenger.


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## Glider (May 14, 2012)

Siegfried said:


> I believe in terms of tonage sunk the Fairy Swordfish was the most succesfull torpedo bomber of the war, so there is an objective basis for this. The aircrafts abillity to fly low and to fly low and attack at night seemed to be its winning card. I've looked long and hard at why the Swordfish got through to the Bismark. The Bismarks heavy AAA was at the time the best in the world on a par with the USN Ford range keeper, a fully triaxially stabalised tachymetric synthetic system with remote power control while the medium 3.7cm AAA was also gyro-sta. The bismarks FLAK was based around triaxially stabilised directors and could throw up 60-80rpm while some of the Quad 2.0cm FLAK units were also stabalised. The reality seems to have been the aircrafts low flying abillity and the aircrafts abillity to exploit the bad weather eg hiding behined waves and clouds. Surviving German sailers complained of seeing the aircraft only intermittantly as they approched.
> 
> My conclusion is that no navy in the world had the abillity to deal with the Swordfish in those circumsatances at that time nor did many aircraft have abillity to exploit those weaknesses in most ships defenses. A few years latter and everyone has vastly improved their AAA.
> 
> Of course the Krisgsmarine never had a chance to finnish its aircraft carriers Graf Zeppelin or Seydlitz so Swordfish were seldim confronted with intercepting fighters.



There is a lot to what you say. Its a personal view but HAA without proximity fuses always struck me as not very effective. The 37mm on the Bismark were very poor, they were almost single shot with each shell manually loaded. The mounting may well have been top draw but the guns were dreadful. This only left the 20mm which were I believe 12 - 18 single mounts which isn't much for a ship of her size.


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## Shortround6 (May 14, 2012)

pinsog said:


> You are making a torpedo runon a ship somewhere in the Pacific Theater, a Zero is moving in to intercept you and you have no fighter escort, or if you do they are busy, would you choose a Swordfish? or an Avenger? The correct answer for everyone on the planet besides Eric Brown is Avenger.



Ah, but after you drop the torpedo you are in the only torpedo bomber that can out turn a Zero.


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## Juha (May 14, 2012)

pinsog said:


> You are making a torpedo runon a ship somewhere in the Pacific Theater, a Zero is moving in to intercept you and you have no fighter escort, or if you do they are busy, would you choose a Swordfish? or an Avenger? The correct answer for everyone on the planet besides Eric Brown is Avenger.



While I might choose Avenger in that situation, would that make much difference. in 42 at Midway Avengers of VT ? operating from Midway suffered 83% losses and the only survivor limbed back badly damaged, ok all six Swordfishes which tried to attack KM heavy units during the Channel Dash were shot down but Fw 190A had more firepower than Zero. The fact was that both Avenger and Swordfish needed fighter escort to survive determined fighter opposition. On the other hand if the target ship had good AA and there was overcast, then Swordfish could use the clouds for sneak approach then made a deep dive to sea level near the dropping point and then drop its fairly reliable torpedo, Avenger on the other hand during the early part of the Pacific War had only one one option, steady rather slow and low approach because the unreliable Mark 21 torpedo had at that time very tight dropping paramets, so Avenger offered much easier firing solution to AA gunners and still it was more probable that Mark 21 malfunctioned than the British 18". In 44 situation was changed because mods allowed dropping of Mark 21 clearly higher and at clearly higher speed.

Juha


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## pinsog (May 14, 2012)

Juha said:


> While I might choose Avenger in that situation, would that make much difference. in 42 at Midway Avengers of VT ? operating from Midway suffered 83% losses and the only survivor limbed back badly damaged, ok all six Swordfishes which tried to attack KM heavy units during the Channel Dash were shot down but Fw 190A had more firepower than Zero. The fact was that both Avenger and Swordfish needed fighter escort to survive determined fighter opposition. On the other hand if the target ship had good AA and there was overcast, then Swordfish could use the clouds for sneak approach then made a deep dive to sea level near the dropping point and then drop its fairly reliable torpedo, Avenger on the other hand during the early part of the Pacific War had only one one option, steady rather slow and low approach because the unreliable Mark 21 torpedo had at that time very tight dropping paramets, so Avenger offered much easier firing solution to AA gunners and still it was more probable that Mark 21 malfunctioned than the British 18". In 44 situation was changed because mods allowed dropping of Mark 21 clearly higher and at clearly higher speed.
> 
> Juha



We should ignore how reliable the torpedo is, we are strictly talking about an airframe here. If you were sent out to attack the battleship Yamato near the end of the war, Would you have chosen the Swordfish or the Avenger?

Eric Brown picked the Swordfish over the Avenger as an overall better aircraft, and that is rediculous. Possibly, under cover of night, with pea soup fog, driving rain, and a hurricane for cover, the Swordfish on one mission out of a thousand might be the better platform than the Avenger. But for the other 99.999% of missions there is no question which would be the better platform to deliver a torpedo, a bomb, or a mine. The fact that Eric Brown picked the Swordfish as an overall better platform for weapons delivery makes me call his overall judgement into question.


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## pinsog (May 14, 2012)

Shortround6 said:


> Ah, but after you drop the torpedo you are in the only torpedo bomber that can out turn a Zero.



GOOD ONE! That is DEFINATELY looking at the cup half-full!!! You should be in sales....


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## Juha (May 14, 2012)

pinsog said:


> We should ignore how reliable the torpedo is, we are strictly talking about an airframe here. If you were sent out to attack the battleship Yamato near the end of the war, Would you have chosen the Swordfish or the Avenger?
> 
> Eric Brown picked the Swordfish over the Avenger as an overall better aircraft, and that is rediculous. Possibly, under cover of night, with pea soup fog, driving rain, and a hurricane for cover, the Swordfish on one mission out of a thousand might be the better platform than the Avenger. But for the other 99.999% of missions there is no question which would be the better platform to deliver a torpedo, a bomb, or a mine. The fact that Eric Brown picked the Swordfish as an overall better platform for weapons delivery makes me call his overall judgement into question.



Partly the torpedo question was connected to airframes, Avenger was tied to Mark 13 (not 21 don't know where I got that, getting old, I think) because the British 18" torpedoes were too long for its bomb bay, one drawback of carrying weapons internally. 1945 was only some 1/6 of the war. As long as many of the ships didn't have Air Warning radars, Swordfish's ability to use cloud cover and deep dive approach was a plus against targets with good AA protection. Swordfish was an archaic plane, but that wasn't only cons it produced also some pluses and those could be utilized far more often than mere 0,001% of missions, for ex. in night operations. 

Juha


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## pinsog (May 14, 2012)

Juha said:


> Partly the torpedo question was connected to airframes, Avenger was tied to Mark 13 (not 21 don't know where I got that, getting old, I think) because the British 18" torpedoes were too long for its bomb bay, one drawback of carrying weapons internally. 1945 was only some 1/6 of the war. As long as many of the ships didn't have Air Warning radars, Swordfish's ability to use cloud cover and deep dive approach was a plus against targets with good AA protection. Swordfish was an archaic plane, but that wasn't only cons it produced also some pluses and those could be utilized far more often than mere 0,001% of missions, for ex. in night operations.
> 
> Juha



You have just been drafted by the US Navy. You are going to fly a torpedo bomber against the Japanese Navy from June 1942 until the end of the war or until you are dead. These will consist of all the historical missions actually undertaken by the US Navy. You have a choice of either the Swordfish or the Avenger. Which one would you trust your life to?


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## Siegfried (May 14, 2012)

The Basket said:


> However much potential the D520 had, it first flew in October 1938. At least 2 years behind where it should be and inferior to the Spitfire and 109 and marginally better than a hurricane. Not good.
> 
> The Fw190 flew only 8 months later. The 520 was old news and marginal news at best. It may have been the best French fighter but 2 years too late.



We are often sympathetic to the French Airforce and its designs, the ones that never were ready in time to confront the German counter attack. However its clear the French really fumbled this extremely badly. 

The country was politically unstable and quite possibly at the verge of a communist revolution, this is nasty stuff given the atrocities in Spain, the Soviet Union and Hungary. Remember, the Spannish civil war began over Priests and Nuns being murdered since the standard Marxist-Leninist ideology at the time regarded the Church as half their problem.

What I am saying is the country was divided and this reflected on their industrial policy.

The country was developing and incredible diversity of airframe types dispersed in small scale design and production and design over several firms in what seemed like a totally incoherant policy. As a result the only good fighter was the MS 460 while the radial Blochs were quite slow. The DW 520 was barely ready and had many problems including handling issues Brown mentions. (Admitedly the RAE Boscombe Down types were incredibly fussy on Handling issues)

The HS 12Y engine only made 860hp while in the 940hp form used in the DW 520 I believe 100 octane was required.

Meanwhile the Germans were introducing the DB601A1a of 1170hp on 87 octane in the Me 109E4 which was was replacing the 1100hp DB601A.

That the French managed this inferiority is an indictment of their systems of Government. They had no treaty of versailes restricting their weapons development, they had no one occupying parts of their country (The French occupied the Saar region of Germany and controlled all the high grade Coal mines) and they were receiving not insignifcant Versailes reperations not scheduled to end untill 1988. 

They had anexed Alsace and Lorrain and its Iron Ore plus they had large Bauxite mines and reserves. I admire French engineering but they really had no chance to realise their intellectual and design excellence.

It's of course de rigour to condemn the Nazi system for being inefficient and corrupt but they actually did extremely well up to the critical phase of 1940. The results of that year speak for themselves.


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## gumbyk (May 14, 2012)

Shortround6 said:


> The D-551 offered speed but in other ways it might be seen as retrograde. Smaller wing means higher wing loading, higher landing speed and larger turning circle. Retractable landing *SKID* means better streamlining and performance, what is does for ground handling??? View from cockpit is also a bit suspect.



What kind of landing skid did it have? A blade would have improved ground handling in some ways (keeping it in a straight line), but a 'spoon' in this would have made it worse.

Do you have a reference for the tailskid? All I have been able to find is that it had a tailwheel.


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## GregP (May 15, 2012)

According to the limited information I have about the D-520, the rop speed was 340 mph and the top speed of the Me 109E was 330 mph, both at best heights.

So the D.520 was faster or at least very cloase to the Me 109E.

I don't see a decided advantage for either aircraft aside from pilot skill ... once the get into theair and past the bad ground manners of the non-locking tailwhell of the D.520, top speed wise. I am not all that familair with climb abd roll, but I think the D-520 climbed at 38200 feet per minute while the Me 109E climbed at 2820 feet per mionute ... about a wash.

To me, they seem VERY closely matched and the D.520 never got developed. When they met, the two were very close.


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## Juha (May 15, 2012)

Hello Greg
Bf 109E-3 was a 350mph bird, D.520 330mph, IIRC, my best sources on it are in my attic, and E-3 climbed to 6000m in 7' 06" but it took 8'59" to do the same in D.520. But D.520 had clearly better range.

Juha


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## Juha (May 15, 2012)

pinsog said:


> You have just been drafted by the US Navy. You are going to fly a torpedo bomber against the Japanese Navy from June 1942 until the end of the war or until you are dead. These will consist of all the historical missions actually undertaken by the US Navy. You have a choice of either the Swordfish or the Avenger. Which one would you trust your life to?



In Pacific Avenger was probably better but USN wasn't the only navy with carriers and Pacivic wasn't the only see where torpedo planes were used. In Med at least in 40-42 Swordfish might well have been a good choice and definitely in North Atlantic if one had to operate from the small RN converted MAC carriers. Later when there were enough proper CVEs around, Avenger probably had the edge. But definitely more than 0,001% of missions flown by SE torpedoplanes were those for which Swordfish suited better.

Juha


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## Francis marliere (May 15, 2012)

Siegfried said:


> The country was politically unstable and quite possibly at the verge of a communist revolution,



Siegfried,

while France was politicaly instable in the 30s, the country was by no way "at the verge of a communist revolution". 
I would add that France did not annex Alsace and Lorraine : these territories were conquested by Germany during the war of 1870 and went back to France in 1918.
To be back on DW.520, I would say that its main problem was how war industry was managed at this time. There were hundreds of new planes (including DW.520) available in june 1940, but most of them didn't have propellers or weapons.

Best,

Francis


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## Tante Ju (May 15, 2012)

Francis marliere said:


> I would add that France did not annex Alsace and Lorraine : these territories were conquested by Germany during the war of 1870 and went back to France in 1918.



The said territories were annexed by Luis XIV at around 30 years war IIRC from German princes who controlled those territories back then. As I understand Alsace/Elsass has a mixed population with a considerable number of German ethnicity.


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## Vincenzo (May 15, 2012)

GregP said:


> According to the limited information I have about the D-520, the rop speed was 340 mph and the top speed of the Me 109E was 330 mph, both at best heights.
> 
> So the D.520 was faster or at least very cloase to the Me 109E.
> 
> ...



the speed of Emil was 345/355 mph, the french tested a captured Emil-3 and in the report noted that was faster. In climb the Emil was greatly superior. (a translation in english of the french report is available on kurfuerst site)


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## GregP (May 15, 2012)

I see we have different sources for the top speed of the Me 109E (or Bf 109E if you prefer).

OK, I don't care. Either way. They are within 10 mph of each other and bullets travel about 1500 - 2000 mph, so the 10 mph speed difference is nothing when they are in range of each other.

The outcome would depend on position and / or pilot skill, which is what I was heading toward anyway. Still looks that way to me.

If I had my choice, I'd take the Me 109E due to what I consider to be better forward visibility, but the D-520 has nothing to be ashamed of and could hold its own when flown well. If both were well flown, the outcome would seem to depend om starting position or who makes a mistake.


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## Vincenzo (May 15, 2012)

true the horizontal speed difference is not large enough for a actual advantage, but the climb advantage (and highly probable acceleratio advantage) is actually usefull.

actual losses in BoF give a clear advantage for 109 14:30 (14 109 losses for 30 520 losses, from JoeB old topic, near same proportion like Hurricane)


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## Dcazz7606 (May 16, 2012)

One aspect of the BoF that I've never heard discussed is French combat formations. Early on the British used the vic and the Germans used the finger four. What formations did the French use. If inferior could this have contributed to the higher lossed suffered by the 520 and others?


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## pinsog (May 16, 2012)

Vincenzo said:


> true the horizontal speed difference is not large enough for a actual advantage, but the climb advantage (and highly probable acceleratio advantage) is actually usefull.
> 
> actual losses in BoF give a clear advantage for 109 14:30 (14 109 losses for 30 520 losses, from JoeB old topic, near same proportion like Hurricane)


 
If the German pilots were in the 520 and the French pilots were flying the 109's I suspect the kill ration would still be 14:30 in favor of the Germans. Training, training, training


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## Vincenzo (May 16, 2012)

you assumed that french pilots were not trained or that their training was not on target?
i think most of french pilots came from pre war courses so sure they were long


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## pinsog (May 16, 2012)

Vincenzo said:


> you assumed that french pilots were not trained or that their training was not on target?
> i think most of french pilots came from pre war courses so sure they were long



My assumption is based on how well the rest of their military did during that time, not very well, and I am assuming the air force would do no better than the ground forces did. Of course, we have no way of knowing if either of us is right, but that is why we are here debating.


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## Shortround6 (May 16, 2012)

There is training and then there is training. Training to do acrobatic displays at airshows may help but it is no substitute for combat training. cross country navigation flights are better than not flying at all but don't make up for a lack of gunnery training and so on. Russians had large numbers of pre-war pilots but many of them were limited in the number of hours they flew per month or per year to save fuel and wear and tear on the aircraft. False economy? is a pilot with 120 hours spread over 3 years since flight school "better trained" than a pilot who has 120 hours in one year after flight school? 

I don't know what the french standard of training was or what their pre-war annual flight times were but just because a majority of pilots were trained in the years leading up to the war, it doesn't tell us much one way or the other about how well they were trained.


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## Juha (May 16, 2012)

IIRC the training in the French AF was good for its time. The kill ratio of Hawk 75A units was a bit better than that of D.520 units, while those of MS 406 and Bloch 151 units were clearly worse, the basic French figter formation was a loose Vic, a bit like that of IJNAF in 1041 - 42, so not as good as LW's Rotte/Schwarm but better than RAF's tight Vic. So IMHO 109E was better fighter than D.520, but latter had longer range and it dived better, at least French though so.

Juha


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## Francis marliere (May 18, 2012)

The problems of French AF were mainly inadequate numbers (they were often outnumbered) and bad doctrine. The high command did not know how to use aviation and pilots paid the price ...


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## Jack_Hill (May 18, 2012)

One fact lingers in my mind for years.
I saw D-520 in flying exhibitions twice at le Bourget, end 70's/beginning 80's'.
Times (magic times)when all aerobatics and all speeds were allowed.
Never been impressed in any of D-520 performing at all.
Except for elegance.
Pilot never bounced her in anyway, gently diving, pulling, gently turning, minimum revs required at anytime and so on. This man (always the same pilot, who finaly crashed with the plane...), for any unknown reason to me, handled the a/c with lots of care and prudence.


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## Siegfried (May 20, 2012)

I don't mean to denigrate the French aviation industry for the D-520 shows two things: its potential and failure. My understanding is that the French Government nationalized its industry. It didn't work. The speed of the Me 109E3 with the 1170ps/cv DB601Aa was 355 mph. The D-520 managed 322mph on its 940cv engine. I've seen 347mph in Wiki but I doubt it.

Maneuverability is the same with the same methodical French tests claiming better responsiveness for the D-520 but also noting its viscous stall and spin characteristics compared to the Bf 109E (a damaged one at that)

The National Socialists had no problem with running free enterprise companies or government owned ones and their policy of aggressive competition was probably more effective than the nationalized quasi communised industry that France experimented with. 

It looks like it would have taken France another 6-9 months to match German quality at around the time the Me 109F1 was entering service advanced versions of the D-520 might have matched the Me 109F1. Advanced versions of the HS 12Y (the HS 12Z) promising a massive improvement. 

The range of the D-520 placed it in a class of its own however.


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## Altea (May 20, 2012)

Hello,


> Shortround6 said:
> 
> 
> > The D-551 offered speed but in other ways it might be seen as retrograde. Smaller wing means higher wing loading, higher landing speed and larger turning circle
> ...


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## Jack_Hill (May 20, 2012)

was it a real emphasis or event budget for further D-520 developement and, worst, deployment ?
Here in france, such a debat still exist.
Sources are highly unreliable for politic reasons. (Isn't it ridiculous, 72 years after...?)
But, maybe, to politics eyes, such a failure and KO is still very hard to explain to french people who still care about WWII.
Yes, D-520 had high wing load, but Dewoitine firm could be easily capable of developping slats, simply copying bf-109's. Did they ? No.
Did HS12 had a real developement potential ? 
If yes, at how much weight, fuel consumption cost ?
For how much power gain ?
At which reliability cost ?
How much structural modifications would have be needed for much bigger engine and fuel capacity integration, still increasing wing load ?
No one will ever know, cuz France was litteraly smashed within 15 days.
Most reliables sources says kill/loss D-520 as 3/1, wich is much more than pretty good.
Hummm, well, pilots fought more than their best. But such a ratio is so high i don't really believe it...
"We will win because we are the strongests" (french 1940 propaganda)
And BOOM!, 1940, may...
"Not any plane can pretend being spitfire or bf109"
Nostradamus, aviation treaty, 1520.


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## Siegfried (May 20, 2012)

Jack_Hill said:


> Yes, D-520 had high wing load, but Dewoitine firm could be easily capable of developping slats, simply copying bf-109's. Did they ? No.



From English language Wikipedia:

"*Additional prototypes*

The prototype was followed in 1939 by two examples: D.520-02 and 03, first flown on 9 January and 5 May 1939 respectively, featuring new sliding canopies, a larger tail unit, and longer Olaer manufactured undercarriage legs; _they also omitted the Handley-Page slats fitted to the outer wings on 01_."

So it seems they had some kind of problem with slats and maybe not enough time to solve it?


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## Jabberwocky (May 20, 2012)

On the development potential of the HS-12Y:

The engine could certainly make over 1100 hp without too major a modification. The -30 and -50 engines were producing a little over 1050 hp in early 1940 and there are a few online sources that put the 89ter at 1200 hp in 1940.

HS-12Z, a more developed version of the engine, is reported as putting out anywhere from 1400 to 1800 hp, but I’m unsure just how different this engine was. 

Soviet development also gives some indication as to how fare the engine could have gone. The M-100 was essentially a licensed-but 12Y and put out 850 hp, 950 hp in the form of the M-103 (basically a developed HS-12YBRS), 1000-1100 hp for the M-103A in 1941 and then up to about 1350 hp for the later M-105 engines (mid 1943 or so).


Reliability:

The HS-12Y derived M-105 was considered more reliable than the V-1710 and Merlins that the Soviets ran in their Lend Lease P-39s, P-40s, Hurricanes and Spitfires. I don’t know how indicative this would be with relation to Western engines in general – apples to apples comparison problem. Soviet maintenance and reliability standards were quite different from Western ones. 

Part of the problem was the sensitivity (at least in the Merlin) to lower octane Russian fuels and different grades of oil. Another was a lack of spares. Another problem was that the Russians simply didn’t possess the same degree of experience on maintaining the western engines. 

Over the Kuban, the Russians reported getting a little as 40 to 60 hours of life out of a Merlin before failures (big ones too, like throwing a con rod). Many of these were refurbished engines though, as the Spitfires supplied to the Soviets were often second hand. The Russians reported that the Merlins in the Hurricane and Spitfire were ‘sensitive’ and often didn’t make specified power on Russian fuel.

V-1710 was considered a touch more robust but still “weak” in comparison to Russian engines in terms of reliability. Engine life varied considerably. Reports are that the TBO for Allisons in the P-39s in Russian service varied from 40 to 50 hours (initially) to about 100-130 hours once the VVS became more familiar with the engine and got more spares/better maintenance procedures (in 1944). In the P-40 the engine was reportedly susceptible to seizures due to metal ingestion.

In 1941/1942 the RAF was getting about 120-170 hours out of the engine its Kittyhawks in the Western desert (around 50-65% of expected engine life), and anywhere from 100 to 180 hours out of the Packard Merlins. 

Much depends on the conditions and operation of the engine. A Soviet pilot stationed close to the front might be expected to spend much less time at lower cruise levels and more time at higher engine settings than a RAF pilot doing sea patrols and battlefield interdiction. 

RAF in the ETO was getting up to 200-240 hours out of its Merlins, but these were much more pampered than the engines in Russia or the Western desert. 

Interviews with Soviet pilots tend to point out that the Allison and Merlins ran much more smoothly than Soviet engines, with less noise, vibration and exhaust particularly at full power. Pilot interviews also tend to point out that the Allison or Merlin were ‘weak’ for the airframes they powered, which may say more about Soviet design philosophy than the engines themselves.


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## Shortround6 (May 21, 2012)

The Hispano was a big slow turning engine. It was 36 liters in displacement which means it was 33% bigger than a Merlin. THis means it didn't need any were near the boost to make it's rated power. It was also much lighter than the Merlin. This means you CAN NOT just up the boost using better fuel without it breaking. 

It's development potential was severely limited unless you are French and also think the Renault Dauphine was one of the great cars of the last century. 

There were at least 3 attempts to "improve" the Hispano 12 Y engine. all added at least 200lb if not closer to 400lbs of weight. ALL changed from the 2 valve heads to 4 valve heads, 2 of them went to fuel injection instead of the ridiculous 6 carburetor set up. I can't be bothered to look up the Russian V-16 and 107 induction systems. 

The Russian V-105 used a narrower bore, a heavier crank, a two speed supercharger, 3 valves per cylinder, better fuel and still maxed out under 1300hp.


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## Altea (May 21, 2012)

> GregP said:
> 
> 
> > The link above suggests the tendency to turn when on the ground was due to lack of a tailwheel locking device ... and ity was corrected in later models.
> ...


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## Altea (May 21, 2012)

Vincenzo said:


> the speed of Emil *was 345/355 mph*, the french tested a captured Emil-3 and in the report noted that was faster.



Not exactly 345/355. Previous british tests showed 571 kph with fully enclosed radiators, and 532 kph with fully opened ones. Except over Spitsberg island on winter, i don't see where can you fly with enclosed radiators.
That mean *a range* from *330 *to *355 *mph. 

On soviet tests, the three brand new serial 109 E, made 542; 546 and 548 km/h respectivly. The last two ones from the 5 commanded, were maybe never tested, or never recieved.

The experimental D-520 made 549 km/h, secund serial one 534 km/h.
It should be noticed that neither Klimovs, nor HS Y-31 had no WEP, CP etc... D-520 flew at their nominal "max cruise" power, this could not be said for the "Emil".
So what was the "E" performance on 30 min, or 60 min power settings, not in short runs ?

Conclusion: its good to do not take "baldders for lanters" * anymore, and to compare what is comparable...

* french popular proverb

Regards


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## Tante Ju (May 21, 2012)

Altea said:


> Not exactly 345/355. Previous british tests showed 571 kph with fully enclosed radiators, and 532 kph with fully opened ones. Except over Spitsberg island on winter, i don't see where can you fly with enclosed radiators.
> That mean *a range* from *330 *to *355 *mph.



This report of German says Emil could flew max speed of ca. 570 km/h with radiator 1/4 open (streamline position) with the water temperatur constant 90 degree celsius (external temperatur was 5 celcius). 90 degree was permissable for DB engine, so I do no think opening radiator was required during full speed flight. Emil can maintain this speed for very long, not only "short runs".

Kurfürst - Meßprotokoll vom 26.4.38, Geschwindigkeit Bf 109 V15a


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## Altea (May 21, 2012)

Tante Ju said:


> This report of German says Emil could flew max speed of ca. 570 km/h with radiator 1/4 open (streamline position) with the water temperatur constant 90 degree celsius (external temperatur was 5 celcius). 90 degree was permissable for DB engine, so I do no think opening radiator was required during full speed flight. *Emil can maintain this speed for very long, not only "short runs".*
> 
> Kurfürst - Meßprotokoll vom 26.4.38, Geschwindigkeit Bf 109 V15a


 
You call *very long * 5 min _Kurzleistung_? 
I know kurfurst and his site enough to say that it is very helpfull, but somewhat tendencious, if not biaised... 
Only by observing the general look of the curve, you can perfeclty see that it was a theorethical, not a measured one.

Regards


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## Vincenzo (May 21, 2012)

for the DB 601A the difference of power from max continuos and 5' setting is 100 hp (from 1000 to 1100 hp) so probably also in max continuous the max speed is over 340 mph (easy 345 mph).
Also the 12Y had short time setting with higher rpm although i don't think is very usefull. also the DB601 is a large slow turning engine (it never got boost like the merlin). if the 12Y not had the power is not a fault of 109, but is right noted the eventual difference of time you can keep the max speed.


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## Tante Ju (May 21, 2012)

Altea said:


> You call *very long * 5 min _Kurzleistung_?



This was theoretical limit. In practice Kurzleistung can be used as long as engine limits (temperatur) is correct, which it was in trials. Of course engine wear will be higher.

If you know any circumstance that prevents use of Kurzleistung for long periods, please let you share.



> Only by observing the general look of the curve, you can perfeclty see that it was a theorethical, not a measured one.



No, report clearly states it was measured test. Calibration of instruments 21.4.38, actual measurement flights the following day on Haunstetten four-way record track 22.4.38., and Augsburg airfield, pilot flying plane Dr.Wurster etc. All details given.

Also French CEAM tests clearly say the Dewo's cooling is insufficent, Me cooling is better. Dewo had to throttle back twice in climb because rising engine temperature.

b) Climb to 5.500 m. PG
The climb speed of the Messerschmidt is slightly superior. It has a quality that favorize it: the engine`s cooling is satisfactory, on the other hand the D.520 had to throttle back due to the increasing temperature of the coolant agent (once at 4500m and once at 3000). The climb of the 109 to 5.000 m took apprx. 6' 20".

http://kurfurst.org/Tactical_trials/109E_FrenchCEAMtrials/french_109e_tt.html


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## Altea (May 21, 2012)

Vincenzo said:


> for the DB 601A the difference of power from max continuos and 5' setting is 100 hp (from 1000 to 1100 hp) so probably also in max continuous the max speed is over 340 mph (easy 345 mph).
> Also the 12Y had short time setting with higher rpm although i don't think is very usefull. also the DB601 is a large slow turning engine (it never got boost like the merlin). if the 12Y not had the power is not a fault of 109, but is right noted the eventual difference of time you can keep the max speed.


Ciao
If you're a real italien, why do you bother using miles for german planes that used metric system as you do?
So suppose 570 km/h at 1100 hp. Reduction on 10% power makes 3.3% loss in speed at best. No?
Certainly more, since you will fly at a higher AoA, but without L/D values at that speed, who knows the induced drag increase...

So 570/ 1.033 or 1.04 makes 545-550. It works. Why not, it's look like russian tests...

Regards


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## Vincenzo (May 21, 2012)

i'm italiano (born and ever lived here but my grandfather and my great grandfather acquired US citizenship or so is in family tales) i use miles because the speed of 109 was indicated in miles in (not my) previous post.
from 1100 to 1000 hp is ~ 10% (is 10% with base 1000) if the plane got 570 km/h (354 miles) with 1100 hp (metric) under cubic root laws it got almost (because commonly when used for up power was considerd at best so if we go for less power is at badest) 552 km/h (343 miles) with 1000 hp taking in the count the higher altitude of max continues setting it's easy that the speed is bit more.


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## Siegfried (May 21, 2012)

The HS 12 series used a integral cylinder block and head an so was leak proof and possibly stronger than the merlin Allison. Soviet versions used inferior fuel but fuel injection. The Swiss achieved over 1500 in their MS 406 developments. the HS 12Z added 4 valves.


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## Altea (May 21, 2012)

Ciao!


Vincenzo said:


> ...
> from 1100 to 1000 hp is ~ 10% (is 10% with base 1000) if the plane got 570 km/h (354 miles) with 1100 hp (metric) under cubic root laws it got almost (because commonly when used for up power was considerd at best so if we go for less power is at badest) 552 km/h (343 miles) with 1000 hp taking in the count the higher altitude of max continues setting it's easy that the speed is bit more.


Ok for higher alt! I forgot about it...


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## Altea (May 22, 2012)

> The country was politically unstable and quite possibly at the verge of a communist revolution, this is nasty stuff given the atrocities in Spain, the Soviet Union and Hungary. Remember, the Spannish civil war began over Priests and Nuns being murdered since the standard Marxist-Leninist ideology at the time regarded the Church as half their problem.
> 
> What I am saying is the country was divided and this reflected on their industrial policy.



I don't remember any atrocities during Tony Blair, François Mitterand or even Leon Blum governement. 

The "Front Populaire" as well as spanish "Frente Popular" was a political calition including for most of them respublicans, socialists reformators and other left and centre partys.

In spain communists had no more than 14 MP/278. Maybe 4 of them were Komintern members. The POUM communists were frankly anti-stalinists, it's why their leader was even assassinated by soviet NKVD during spanish civil war, at general shock. Don't see any risk of communist revolution there...

Well before any political crisis, the deplorable state of the industry was not allowing any success of french rearmement plans. Due to mental and technical retardation from french headquarters and plane builders the plan I from 1934 was a failure. Looking at LéO-206 and LéO -257B commanded in 1935 cause no better choices, it was obvious that it was hard for them to leave outmoded but proven techniques, sclerotic ideas.

Well what can we say if reported to the end of 1937 france was still rearming with D-501, D-371 and SPAD-S 510 when I-16 and Messerschmitts were fighting in spain. And Polikarpov I-17 triomphating at Paris aviation salon. 

At this condition, considering the full failure from existing and future rearmement plans, the radical-socialist Pierre Cot from Blum Governement made the only clever proposal. Massive deliveries from Soviet Union that could send in one-2 months the mid-30ies one year french military production, in exchange of technology transfer and gold francs, of course... 

J'v got no doubt that in 1936-37, I-17 with HS engines and chauvière props, and I-16 with modernised american Cyclones could perform better than D-500, D-371 ans SPAD S 510.

As well as SB-2 against MB-131 or Potez 540. 

Or DB-3F for Bloch MB-200, Amiot 131, or Farman 221.

No doubts than hundreds of Tupolevs (even some TB-7 why not, with french help...) and Iliushins massed over french boarder should have been made Hitler thinking twice before invading Tchecoslovakia.

Regards


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## Altea (May 22, 2012)

Tante Ju said:


> This was theoretical limit. In practice Kurzleistung can be used as long as engine limits (temperatur) is correct, which it was in trials. Of course engine wear will be higher.
> 
> If you know any circumstance that prevents use of Kurzleistung for long periods, please let you share.



Why don't you manage yourself to read understand yourself the docs you post?

_the A-1, with 1,30 ata manifold pressure for 990 PS output at 0m, and 
the Aa, with 1,35 ata manifold pressure for 1045 PS output at 0m, both for cleared for 5 minute periods._

At least from *all available * speed curves from the E-1/E-3 try to do not choose an aberrant one. The tested old plane had no standard hydro-coupling, and too few points to establish a *reliable* curve from it.



> No, report clearly states it was measured test. Calibration of instruments 21.4.38, actual measurement flights the following day on Haunstetten four-way record track 22.4.38., and Augsburg airfield, pilot flying plane Dr.Wurster etc. All details given.


You should also learn the difference between *a wind tunnel *calibration from reference laboratory instruments with uncertainlies chain description and a simple conversion IAS/TAS table (even a controled one).



> Also French CEAM tests clearly say the Dewo's cooling is insufficent, Me cooling is better. Dewo had to throttle back twice in climb because rising engine temperature.



That's true, first serial D-520 were often suffering quality standards defaults and other teething troubles. Now, making from some cases a general law, is rather abusive.


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## Altea (May 22, 2012)

Vincenzo said:


> actual losses in BoF give a clear advantage for 109 14:30 (14 109 losses for 30 520 losses, from JoeB old topic, near same proportion like Hurricane)



J'm not sure that those _actual losses _ can allow to make any definite conclusion about D-520 vs Me-109 results. German archives are far from being complete, there are lacking some pages from war diaries and complete account with units diary losses-deliveries balance is not made.

I will advice E de Mombeek books, articles.

Regards


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## DonL (May 22, 2012)

> J'm not sure that those actual losses can allow to make any definite conclusion about D-520 vs Me-109 results. *German archives are far from being complete, there are lacking some pages from war diaries and complete account with units diary losses-deliveries balance is not made.*



Is there any prove or source for this claim?

To my knowledge all german archives are totaly complete and very accurate till November/December 1944! After this timeline till Mai 1945 german archives are not accurate, but till the end of 1944 I haven't heard from such an issue.


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## Altea (May 22, 2012)

DonL said:


> Is there any prove or source for this claim?
> 
> To my knowledge all german archives are totaly complete and very accurate till November/December 1944! After this timeline till Mai 1945 german archives are not accurate, but till the end of 1944 I haven't heard from such an issue.



Obviously your knowledge exceeds by far the known published data, can you provide the faith and traceability for each Me-109 produced from 1936 to june 1940 the 24th?

How many fighters did Luftwaffe lost during BoF?


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## Tante Ju (May 22, 2012)

Altea said:


> Why don't you manage yourself to read understand yourself the docs you post?
> 
> _the A-1, with 1,30 ata manifold pressure for 990 PS output at 0m, and
> the Aa, with 1,35 ata manifold pressure for 1045 PS output at 0m, both for cleared for 5 minute periods._



Yes, pilots were instructed not to use it for more than 5 minutes. Maximum power has great wear on engine, but in combat I doubt any pilot would care about that, if his life depends on it.

I am aware for example Soviet standard was not to give maximum time limit. For example Yak 9U could thesis fly unlimited on maximum power... reality was engine never lasted more than 20-30 hours... with all that 'unlimited use' stuff or no.



> At least from *all available * speed curves from the E-1/E-3 try to do not choose an aberrant one.



What is 'abberant' about it? To me it seems you made some thought in your mind, and now that papers show otherwise, you want to dismiss papers, instead of changing your mind.

There are several 109E test on Kurfurst seit. You can check yourself.

Kurfürst - Meßprotokoll vom 26.4.38, Geschwindigkeit Bf 109 V15a
Says top speed is *574 km/h* on measured plane.

Kurfürst - Baubeschreibung für das Flugzeugmuster Messerschmitt Me 109 mit DB 601.
Says top speed is *570 km/h*, manufacturer assumes guarantie for this speed within 5%.

Kurfürst - CEMA : Performance trials with the captured Messerschmitt Bf 109E-3 WNr.1304
French trials. "In general, the first tests made at the Center concerning the Messerschmidt 109 appear to confirm the performances claimed by the Germans. In particular the maximum aircraft speed is about 570 km/h at around 5000 m."

Kurfürst - Swiss level speed results for Bf 109E-3, WNr. 2404, J-347 with Escher-Wyss and original VDM propellers.
Swiss trials of export aircraft. *565 km/h* with original German propeller.

Two German, one French, one Swiss test, different aircraft, all say the same... 



> The tested old plane had no standard hydro-coupling, and too few points to establish a *reliable* curve from it.



Where does report say that? Any proof or source?



> You should also learn the difference between *a wind tunnel *calibration from reference laboratory instruments with uncertainlies chain description and a simple conversion IAS/TAS table (even a controled one).



You suggest that the trial results were all made up, and German were fooling themselv?  So, sohw me result which satisfy your many requirements for measurement of top speed.



> That's true, first serial D-520 were often suffering quality standards defaults and other teething troubles. Now, making from some cases a general law, is rather abusive.



Sure... you claimed the 109 cannot upkeep its speed for long, provide no evidence, reports show you were incorrect, so now you say what French say about own aircraft is really due to "teething trouble". Come on!


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## cimmex (May 22, 2012)

Altea said:


> Obviously your knowledge exceeds by far the known published data, can you provide the faith and traceability for each Me-109 produced from 1936 to june 1940 the 24th?
> 
> How many fighters did Luftwaffe lost during BoF?


I’m sure you can find every single German loss during this period at the Bama in Freiburg. AFAIK total 169 SE fighters were lost during the French campaign.
cimmex


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## Vincenzo (May 22, 2012)

Altea said:


> J'm not sure that those _actual losses _ can allow to make any definite conclusion about D-520 vs Me-109 results. German archives are far from being complete, there are lacking some pages from war diaries and complete account with units diary losses-deliveries balance is not made.
> 
> I will advice E de Mombeek books, articles.
> 
> Regards



i think that your info are wrong or outdated in "The battle of France. Then and now", the book used from JoeB for the calculation, there is no a word on lack data for luftwaffe. 

limitating in the 109 vs SE fighter in BoF the 109 had 167 losses (74 Hurri, 24 Spit, 23 Hawk 75, 14 D 520, 32 MB&MS), have not checked for strictly BoF or Phoney War + BoF


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## Njaco (May 22, 2012)

Altea, please use one post and not multiple.


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## Altea (May 22, 2012)

Vincenzo said:


> i think that your info are wrong or outdated in "The battle of France. Then and now", the book used from JoeB for the calculation, there is no a word on lack data for luftwaffe.
> 
> limitating in the 109 vs SE fighter in BoF the 109 had 167 losses (74 Hurri, 24 Spit, 23 Hawk 75, 14 D 520, 32 MB&MS), have not checked for strictly BoF or Phoney War + BoF



Yes but from W. Murray from 1428 Luft losses 367 were fighters (maybe some Bf-110). 235 109E were lost to all causes from P. Facon. All causes can be accidents, but merely due to battle damage.

About "official" D-520 balance sheet, 158 victories were claimed, more than 100 of them confirmed. 85 planes lost but about 60% abandonated on airfields during the retreat. 
Well, i have no doubts that french pilots overclaimed exactly as the others elsewhere (maybe less than RAF in 1940). Moreover many victories were shared ones. From Patrick Facon researches there were more possible victories over 109 than that, except that there were shared by other planes and units. Difficult to establish 72 years later if destroyed planes were due to Hurries, D-520 or H-75 squadrons.

Each one of them faught and claimed german planes in same time and places, during same "mélées" (collective dogfights). Can you explain what whay the exact share provided by JoeB was maid between them?

Regards


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## Altea (May 22, 2012)

Ok, can you find exact serial numbers of 109A, B, C D and E that went to spain, with shipment date, deliveries, loss date etc? For the moment nobody could, but may be you can...


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## FLYBOYJ (May 22, 2012)

Gentlemen, one warning - if the bickering gets out of hand I will start banning people.


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## JoeB (May 22, 2012)

Altea said:


> Yes but from W. Murray from 1428 Luft losses 367 were fighters (maybe some Bf-110). 235 109E were lost to all causes from P. Facon. All causes can be accidents, but merely due to battle damage.
> 
> About "official" D-520 balance sheet, 158 victories were claimed, more than 100 of them confirmed. 85 planes lost but about 60% abandonated on airfields during the retreat.
> Well, i have no doubts that french pilots overclaimed exactly as the others elsewhere (maybe less than RAF in 1940). Moreover many victories were shared ones. From Patrick Facon researches there were more possible victories over 109 than that, except that there were shared by other planes and units. Difficult to establish 72 years later if destroyed planes were due to Hurries, D-520 or H-75 squadrons.
> ...


I would recommend getting and reading the book I mentioned, "Battle of France-Then and Now" by Peter Cromwell. Then you can see the level of detail he provides for all the AF's records.

The points you raised aren't so relevant, IMHO. With a book as detailed as Cromwell's, there's no reason to start with reports of total losses to all causes and try to figure out which ones might have been to air combat, Cromwell covers it case by case.

Same goes for counting stuff like shared victory claims, etc. The Cromwell books tells you when, where and how individual a/c were lost. Of course there is some ambiguity on a few losses, but I think the count I quoted is basically accurate. And anyone with any experience in counting losses in WWII (or other air wars, for that matter) knows that it's pointless to assess the success of fighters by counting what they claimed. So the fact that D 520 units claimed a certain kill ratio is by itself meaningless, likewise the claimed ratio's by Hurricanes or 109's in the France campaign. Although that said, the claims of the French units do not seem particularly excessive relative to actual German losses, as mentioned in the post above comparing the D 520 claims v 109's to the apparent actual 109 losses to 520's.

As others mentioned, German fighter unit and a/c records for this period of the war are typically pretty complete. Other books besides Cromwell's focusing on BoF, for example Brian Cull's "Twelve Days in May" which focuses on the RAF Hurricane units in the campaign combat by combat, give similar results to Cromwell as far as Hurricane v 109 (around 2:1 kill ratio in the 109's favor, similar to its results v the D 520).

Joe


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## Shortround6 (May 22, 2012)

On the subject of the Hispano engine ( and Russian derivatives) and possible WEP settings it is hard to say that any particular rule or limit applied at all times. 

You have factory ratings, which using air forces/squadrons could ignore at their own peril. You have unit diaries or pilot reports which can describe settings that don't agree with factory limits. The Russian V-105 used a heaver crankshaft, 3 valve heads and better gas than the French had in squadron service so Russian practices might not hold up well to French conditions. 
There are two basic reasons for limiting (placing a limit) on engine power. One is to ensure long life by keeping down wear on the pistons, rings and bearings. The other is to prevent detonation which can result in catastrophic failure in just minutes if not in seconds. A hot engine is much more likely to reach detonation limits (although over heated oil looses some of it's lubrication qualities) which is why many engines are allowed to operate at certain levels subject to holding a temperature limit. 
The ability of a pilot to exceed factory limits depends a lot the individual airplane. On many American planes the boost limit was under the pilots control, The British used an automatic boost limiting device which freed the pilot from having to fiddle with the boost limit as the plane climbed and dived. Germans had something similar if not more complicated in their single lever control. The British and German boost limiters could be "modified" by squadron mechanics as could the American boost control. I don't know about other nations. 
Almost every supercharged aircraft engine ever made could make more boost at sea level than was good for it. It is this "extra" supercharger capacity that was used for WEP levels. The problem with trying to figure out at this point in time wither a particular engine engine could or could not use a certain amount of over boost (or WEP) is that it often varied depending on the day in question. An engine might survive just fine on a 30-40 degree (F) day for 4-5 minutes at a certain manifold pressure because the radiator/oil cooler had extra cooling capacity and the intake air was cool while another identical engine might hole a piston or throw a rod in just 2-3 minutes on a 100-110 degree day. 
Over revving engines to get more power is especially frowned upon. Friction goes up with the square of the speed and so do the loads on the bearings and reciprocating parts. 
There is also no way to reduce the supercharger speed. increasing engine speed by 100rpm could increase supercharger impeller speed by 700-1000rpm. Since the power to drive a supercharger goes up with the square of the speed and 30-40% of the power goes into heating the charge this can push the engine closer to the detonation limits. 
You may be able to over rev an engine while keeping the throttle part closed to limit air intake and power but this also depends on the propeller. A constant speed prop is going to keep increasing the pitch until it hit's it maximum pitch angle to keep the engine at the maximum rpm unless overridden. 
A Problem with the Hispano engine is that it is the oldest V-12 engine used in large numbers in WW II. it is very light for it's size and so has little reserve of strength. It's designers were not dumb but because of it's age it was designed before 87 octane fuel came into use. ( I believe the RAF didn't start using 87 octane until 1934?) If all you have is 80 octane fuel or below designing a heavy engine to stand up to high cylinder pressures doesn't make much sense because without the higher octane fuel you can't reach those pressures. 

While we have the stories of the pilots who abused their engines and made it home, we do not hear the stories of the pilots who abused their engines and holed pistons or put rods through the side of the block or launched cylinder heads or cylinders through the cowl and either crashed or became prisoners. Maybe 10 pilots got away with it for every one that didn't, maybe it was 50/50. we don't know.


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## Vincenzo (May 22, 2012)

FLYBOYJ said:


> Gentlemen, one warning - if the bickering gets out of hand I will start banning people.



sorry i don't understand the warning, what we have writed that is not ok?


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## FLYBOYJ (May 22, 2012)

Vincenzo said:


> sorry i don't understand the warning, what we have writed that is not ok?


Your posts are fine, we have one contributor who is walking a fine line. Now please carry on...


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## Altea (May 23, 2012)

Tante Ju said:


> .
> 
> I am aware for example Soviet standard was not to give maximum time limit. For example Yak 9U could thesis fly unlimited on maximum power... reality was engine never lasted more than 20-30 hours... with all that 'unlimited use' stuff or no.



False
The Klimov 107 yes, had a CP setting for the first time in Klimov's engine history. See graphs or thechnical docs. His standard TBO was of 50 = 2 x 25 hours for *early* engines with intermediate dissassembly, and so if the *technical comission *was giving the allowance after exam, it went back to units for the 25th last hours.
Obviously you *are not* a specialist on soviet engines, and probably not a specialist on engines at all. On previous exemple, it's look like you're aware of nothing special and only substituting your own fantasy to your lack of knowledge. What have you red about the subjet?

Some other things, 
first:


> In practice Kurzleistung can be used as long as engine limits (temperatur) is correct, *which it was in trials.*


then


> Yes, pilots were instructed not to use it for more than 5 minutes. Maximum power has great wear on engine, but in combat I doubt any pilot would care about that, if his life depends on it.



It's very different to use Kurleistung as long as you want and only if yout life depends on. And i, (we) are still waiting the concrete value for the "long time" it was used during those trials.

If you're not disturbed by your own contradictions, you will undersand that your opponent could be.

About using the engine (or plane) well over it's limitations: you can always do that, but at your own fear and risk! And consequences could be an engine failure for myriads of reasons as mechanical overstress or fatigue, if not during your overboosted flight, probably for next ones.*
This is much more annoying than an accelerated wear, and does not always prevent...

In my case, i'd rather trust manufacturer instructions than your own interpretations. Certainly, he knows better.


Regards

* It's not a binar logic, back or white, yes or no, 1 or 0...
I'v got a tin can with beans. It' expiration date is the 23/07/2009 14:37  !
So what the hell happend there on july 2009 the 23th between 14:36:59 and 14:37:01? Massive beans transformation to gremlins, bloody revolution? I'm afraid to open now... And i won't, we are in 2012. But someone else can take the risk and eat them.

So i'm sure that using 5 min 32 secunds _Kurtzleistung_ instead of 4 min 59, youre not in jeopardy. But i would not abuse tu much and to often if i want to be and last...


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## Altea (May 23, 2012)

Good post, except on aviation fuel used in France, it was 85 octanes since 1929.

The compression ratio passed from 5.8 to 7 from the Y-31 to the Y-51 due to 100 octanes fuel use. The "ubuesque" of the situation is that 100 octanes fuel was obtained by frenchman's Eugène Houdry cracking method. His patent founding no interest from french officials, he went to USA and sold it to americans companies with great success.
Eugene Houdry - Wikipedia, the free encyclopedia.

Anyway in 1940 France was dependent from US, and British high octane fuel deliveries. The faith of Hispano engines, was also conditionned by their story. They were mainly Transatlantic flights/ distance records engines at the beginning. It can explain some retrograde solutions as the air cranckshaft cooling and limited oil radiator. On Y-31 it was a simple exchanger (beard) on the crankcase..

http://www.hydroretro.net/etudegh/hispanosuiza.pdf


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## DonL (May 23, 2012)

@ Altea

What is your agenda or intention?

As I understand from your other posts you have doubts about the high speed of the Bf 109E with "Kurzleistung" (30min) or Dauerleistung compare to the Dewoitone 520.

As you can see from this sheets
Kurfürst - DB 601, 603, 605 datasheets - DB 601 Aa
Kurfürst - DB 601, 603, 605 datasheets - DB 601 A-1

Most Bf 109E1-3 were built with the DB 601A-1.
So if you look at the datasheet you will see which 30min performance for the DB 601A-1 was "ok".
960 PS at 5000m altitude for 30min, against 1020PS at 4500 altitude for 5 min!

As we have seen from many tests (France, Swiss, Germany) the Bf 109E was good for 570km/h at 5000m and 500km/h at SL with 5min 1020/990PS Kurzleistung. So 960PS for 30min (5000m altitude) isn't that much less compare to 1020PS for 5min (4500 altitude) , and it is obvious that the 960PS for 30min would be more then enough to compare with the Dewoitone 520.

From your written numbers 549km/h and 534km/h for the Dewoitone 520 for highest speed at *altitude* and not SL, to my opinion the Bf 109E with 960PS for 30min would have had always the edge, very small compare to the 549km/h and larger against the 534km/h.

A few questions, from which altitude came the 549km/h / 534km/h? What was the best altitude output performance of the Dewoitone 520?
How long could the engine of the Dewoitone 520 hold it's best output performance (5min, 15min, 30min etc..)?


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## Tante Ju (May 23, 2012)

Altea said:


> And i, (we) are still waiting the concrete value for the "long time" it was used during those trials.



Trials say the temperature was 'constant'. It's quite clear IMHO what it means. It means temperature is not rising, and can be maintained. Indefiniately if you like.

You were shown German trials which shown 570 km/h was maintained with the radiator 3/4 closed and with still maintaining proper coolant temperature. 
You were also shown French testing of their own Dewo which clearly stated the Dewo's cooling capacity was insufficient compared to the Bf 109E and engine temperatures did not permit long runs on even nominal power. 

You have claimed both is impossible:



Altea said:


> Not exactly 345/355. Previous british tests showed 571 kph with fully enclosed radiators, and 532 kph with fully opened ones. Except over Spitsberg island on winter, i don't see where can you fly with enclosed radiators.
> That mean *a range* from *330 *to *355 *mph. ... D-520 flew at their nominal "max cruise" power, this could not be said for the "Emil".
> So what was the "E" performance on 30 min, or 60 min power settings, not in short runs ?



What have you shown to prove that....? Nothing. You did not even try.. trials say exact opposite. So what is its basis? You seem to suggest that the top speed of the Emil was not realistic, and try to argue that it was just for short burts, like a racer, but its not true.

So sorry to think your wrong in that. The Emil was not restricted to 'short runs' at max power 'near the Spitzbergen'. The Dewo was not limited by an arbitrary time limit, but the fact that its coolant system was undersized (perhaps to get better performance from limited engine..?) and soon reached temperature limits, making an actual engine seize rather likely, if pilot did not throttle back. Shortrund already expalained in post very well. The wear would be higher I agree but not prohibitive for extended use, if required. For simple speed runs, the 30 minute rating is just 60 HP less, as DonL showed.


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## Njaco (May 23, 2012)

Altea - I told you to keep your posts to one post and not multiple.



> Obviously you *are not* a specialist on soviet engines, and probably not a specialist on engines at all. On previous exemple, it's look like you're aware of nothing special and only substituting your own fantasy to your lack of knowledge. What have you red about the subjet?



For this insult you are getting an infraction. Stick to the facts and don't personally comment on a another member like this.


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## Siegfried (May 23, 2012)

Altea said:


> I don't remember any atrocities during Tony Blair, François Mitterand or even Leon Blum governement.
> 
> The "Front Populaire" as well as spanish "Frente Popular" was a political calition including for most of them respublicans, socialists reformators and other left and centre partys.
> 
> ...


 
Leon Blum nationalised the French aviation industry in a short 6 weeks return to Government. The mess in privat industry can perhaps be attributed to militant communist/revolutionary unions and the resulting instability, the Blum governments previous terms in office. Basically the Leftist regimes didn't seem to believe in private industry and so failed to build it. Perhaps socialism works but instability never does.


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## FLYBOYJ (May 23, 2012)

STICK TO THE SUBJECT - ALTEA, YOU ARE ALMOST DONE HERE. STOP WITH THE INSULTS OR YOU WILL BE BANNED!


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## Altea (May 24, 2012)

Tante Ju said:


> Trials say the temperature was 'constant'. It's quite clear IMHO what it means. It means temperature is not rising, and can be maintained. Indefiniately if you like.


*Constant* with what tolerance? +,- 0.5°C, something like that? And how do you imagine the scene? Pilot only concentraded only on it temperature instrument, not on throttle, flight line, contant altitude etc...

Concretly, pilot managed to keep the T° on a certain gap (that amplitude is not precised...) during his (different?) run(s) at flight level. J'm sure he managed to not overheat and even maintained more or less constant the T° during his runs that duration is precised nowhere in the doc, except for engine settings limitation.



> You were shown German trials which shown 570 km/h was maintained with the radiator 3/4 closed and with still maintaining proper coolant temperature.



And why do you insist *heavily and only* on that doc, there are no other different ones?

http://www.spitfireperformance.com/spit1-109espeed.jpg

Why Flugzeughandbuch datas are not OK? How do you explain discrepancy between different soviet, swiss, british, german, french tests?

Regards


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## Altea (May 24, 2012)

Siegfried said:


> Leon Blum nationalised the French aviation industry in a short 6 weeks return to Government. The mess in privat industry can perhaps be attributed to militant communist/revolutionary unions and the resulting instability, the Blum governments previous terms in office. Basically the Leftist regimes didn't seem to believe in private industry and so failed to build it. Perhaps socialism works but instability never does.


Before nationalisation, the french private industry had it chance, but it was weak and depending on 95% from state commands. Laurent-Eynac and Caquot were not leftist, and supported aeronautical (private) industry with public grants, leaving progress initiative to private firms and entrepreneurs. 
At result: a failure, not almost but near complete, from 1928 to 1933. Without special troubles inside factories...

The same error was repeated from 1934. At results, french governement with all tendencies, including even french nationalists from ultra-right hand, was fed-up with the situation. Is why the privatisation was adopted at waste majority of the deputy chamber, not only leftists: 485 voices against 45 maybe corruted by industrial magnates.

I would also recall the fact that many aviation industries reminded private, as Breguet, Caudron, M-S and Amiot, and the whole engine industry, this weakest branch paradoxally needing the highest recapitalisation.

Regards


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## DonL (May 24, 2012)

> Why Flugzeughandbuch datas are not OK? How do you explain discrepancy between different soviet, swiss, british, german, french tests?



The german,french and swiss test are very close to each other, there is very very small discrepancy.

The german and french test are very good documented with much datas and description.

Do you have exact data's for your mentioned russian tests?

Gasoline, engine poweroutput, altitude etc. 
Your claimed high speed data's from your mentioned russian tests make only sense, if we know the test description and other test datas.
Otherwise it's meaningless and you can't claim a wide discrepancy.


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## Njaco (May 24, 2012)

Altea, last warning! 

KEEP YOUR RESPONSES TO ONE POST! 

Use the mulit-quote, cut-n-paste, etc.


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## Siegfried (May 25, 2012)

Altea said:


> Before nationalisation, the french private industry had it chance, but it was weak and depending on 95% from state commands. Laurent-Eynac and Caquot were not leftist, and supported aeronautical (private) industry with public grants, leaving progress initiative to private firms and entrepreneurs.
> At result: a failure, not almost but near complete, from 1928 to 1933. Without special troubles inside factories...
> 
> The same error was repeated from 1934. At results, french governement with all tendencies, including even french nationalists from ultra-right hand, was fed-up with the situation. Is why the privatisation was adopted at waste majority of the deputy chamber, not only leftists: 485 voices against 45 maybe corruted by industrial magnates.
> ...



After the nationalisation of most of the French aviation industry, in May 1936 French aviation workers in what is by most historians referred to as communist inspired unions, launched the greatest strike of “the 3rd Republic” not only withdrawing labour but occupying factories.

The book “State Capitalism and Working-Class Radicalism in the French Aircraft Industry By Herrick Chapman” is one source of information.

Also the book: “Fortress France: The Maginot Line and French Defenses in World War II By J. E. Kaufmann, H. W. Kaufmann”

1936 would have been a critical year for aircraft such as the Bf 109, Spitfire an important engines such as the Merlin and DB600/DB601, when the critical ground work for the early war periods critical aircraft designs and the costs associated with this would have effected R&D the French were having a massive strike based on ideas around class warfare.

National Socialist ideology or rather objectives were based around the idea of the harmonisation of capital and labour (rather than adversarial) as well as the elimination of class conflicts for the common good of the folk (people). The “race” was to be ahead of the idea of an abstract nation or an abstract economy, wealthy or poorer classes. Unions were allowed and given representation even on board of directors but if any factory owner or militant unionist stepped out of line the National Socialists would begin to knock heads together. Industrial disputes were to be resolved by talking and any dispute based not on a work related issue but on an ideology such as the Marxist idea of class warfare and the inevitable eliminatin of classes and the rule of the proletariat would not be tolerated. 

To National Socialist It didn’t matter if something was done by government or private industry what mattered to National Socialists was being dynamic: doing something and effective. Aggressive completion and fly offs were favoured. AFIKT only Junkers was nationalised (not because Hugo Junkers was anti-nazi) but because his company went broke and his directors and shareholders revolted.
Contracts started out as cost plus incentive and then went to fixed price with renewal at lower prices.
Without an air force in the 1930s the Germans subsidised the airlines and hence had by far the largest passenger mile numbers of any nation in Europe I think several times larger than France and UK combined.


In France things were different:
In 1934 Denian began to build a 1000 plane air force, this action ensuring old types of aircraft were built rather than new types. It also seems to have retriggered German rearming well beyond the repudiation of Versailles Treaty. (Incidentally this hideous treaty was reinstated after WW2 and the final payment made in 2010)
In 1936 2950 obsolescent aircraft were ordered of PLAN I not the more modern PLAN II.
New Models were not ordered belatedly till 1937. They tried reform and ordering PLAN V aircraft in 1938.


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## Altea (May 25, 2012)

DonL said:


> The german,french and swiss test are very close to each other, there is very very small discrepancy.
> 
> The german and french test are very good documented with much datas and description.



And you call *very, very small* discrepancy the (*30 mph*)  difference between 500 km/h (310 mph) from Messerschmitt booklet and Messung E.Stelle Bericht Nr. 2652/39, 280 mph at SL? 

Considering Prince and Preston bothering to explain each 3 (not 30!!!) mph differcence between Sitfires, you're just kidding or something like that...

Moreover you've got one linear, and one broken from 0 to rated altitude curve. What's the matter? Wich one is the good one?


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