Dewoitone 520 question

[DonL]

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.

 

[Altea]

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?

 

[Tante Ju]

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!

 

[cimmex]

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

 

[Vincenzo]

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

 

[Njaco]

Altea, please use one post and not multiple.

 

[Altea]

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

 

[Altea]

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...

 

[FLYBOYJ]

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

 

[JoeB]

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?

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

 

[Shortround6]

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.

 

[Vincenzo]

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?

 

[FLYBOYJ]

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...

 

[Altea]

.

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...

 

[Altea]

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

 

[DonL]

@ 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..)?

 

[Tante Ju]

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:

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.

 

[Njaco]

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.

 

[Siegfried]

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
Regards

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.

 

[FLYBOYJ]

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