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Codger1949
07-23-2008, 06:50 AM
Would somebody please tell me which performs better at low alt? Or which is the superior spit in whatever way?

Kurfurst__
07-23-2008, 06:58 AM
The +25 version. It is the same aircraft essentially, with much higher powered engine.

The e version has .50 cal Browning HMGs instead of the .303 MGs, but less power.

Codger1949
07-23-2008, 07:19 AM
So I guess the 25lb. can outturn and outrun the IXE?

julian265
07-23-2008, 07:21 AM
Codger, I suggest you download IL2 Compare. It contains the max speed vs altitude curves, turn time and radius vs speed, climb rate vs altitude, and a bunch more such as max safe speed, armament and ammunition for every aircraft in IL2. I think 4.07 is the latest version.

JG53Frankyboy
07-23-2008, 07:29 AM
Originally posted by Codger1949:
Would somebody please tell me which performs better at low alt? Or which is the superior spit in whatever way?
http://war.by-airforce.com/downloads/il2compare-4.07.html

<- tool that is always helpfeull for a first "look".
but sure after that a "reality" check in game is recommended http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif
but most times the datas are showing good what is hapening in game.

Codger1949
07-23-2008, 07:40 AM
Ok thanks. I'll check out the compare thingy. Hardball's compare program doesn't even mention the 25lb.

Xiolablu3
07-23-2008, 07:43 AM
Originally posted by Codger1949:
So I guess the 25lb. can outturn and outrun the IXE?

Not sure about outurn, it is a little faster BELOW the IXe's Full throttle Height (lbs boost pressure is no use ABOVE or AT FTH, so its identical to a 18lbs boost mkIX above this height)

I guess it might turn a little better thanks to the extra power at lower alts, but it will not be a big advantage.

18lbs boost (mkIXc/MkIXe) to 25lbs (MkIX 25lbs) boost adds a few mph at below FTH. (The height which top speed is achieved)

The 25lbs is the Spitfire you should choose if you want the very best available in the game, since there is no SPitfire XIV.

See for yourself how the prototype 25lbs boost JL165 Spit performed relative to the 18lbs boost model, the original RAE report...

http://www.spitfireperformance.com/spitfire-IX.html

Look for the title JL165 235lbs boost trials down the page.

JG53Frankyboy
07-23-2008, 07:47 AM
Originally posted by Codger1949:
Ok thanks. I'll check out the compare thingy. Hardball's compare program doesn't even mention the 25lb.

to ad , Hardabll was using the perfomance datas out of the il2cmpare tool for his thing.

TinyTim
07-23-2008, 07:48 AM
Last time I tested them (I think it was 4.07, no sure tho):

Level speed

Spitfire IXc 25lb: 570kph
Spitfire L.F. IXc: 540kph

which agrees nicely with IL2compare. (note even LF gets better above 7km, let alone HF):

http://shrani.si/f/1F/su/S1RUfXb/0000.jpg

Xiolablu3
07-23-2008, 07:54 AM
I am really bad at reading those little diagrams, does the turn time show the 25lbs outturning the 18lbs, or vice versa pls?

TinyTim
07-23-2008, 08:02 AM
Yeah, since red line is below the blue at all speeds it means that the "red" plane (25LBer) needs less time to do a complete circle than "blue" plane (18LBer, or LF).

Exaple: at 250kph blue one needs 25 seconds, and red one needs between 22 and 23 seconds.

But one needs to keep in mind that LF version is the one with clipped wings, so it should turn worse.

SlickStick
07-23-2008, 09:49 AM
Originally posted by Codger1949:
Ok thanks. I'll check out the compare thingy. Hardball's compare program doesn't even mention the 25lb.

In Hardball's program, select the "Spitfire LF Mk.IX C, Supermarine" as one of the planes and move your mouse cursor over the categories for speed, turn-time, etc. and the +25lbs. specs will pop-up.

Xiolablu3
07-24-2008, 07:45 AM
Originally posted by TinyTim:
Yeah, since red line is below the blue at all speeds it means that the "red" plane (25LBer) needs less time to do a complete circle than "blue" plane (18LBer, or LF).

Exaple: at 250kph blue one needs 25 seconds, and red one needs between 22 and 23 seconds.

But one needs to keep in mind that LF version is the one with clipped wings, so it should turn worse.

Yeah of course, doh, should have noticed that. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Thanks for the explanation.

Ba5tard5word
07-24-2008, 10:44 AM
I've been meaning to ask about this...

What does the "25lbs" notation mean for the plane?

Also the CW (clipped wing) versions are meant for low-altitude flying, right?

Xiolablu3
07-24-2008, 12:30 PM
Its the manifold pressure, better fuels allowed this boost pressure to be higher and give better performance. The Spitfire's Merlin for example started the war with a max boost of 6lbs I think, and ended the war with a boost of 25lbs.

The US used inches (for example 72 inches boost on the P51 Merlin was around 25lbs I believe)

The Germans used ATA, as in the 1.42 ATA in the Bf109.

All are essentially the same thing just measured differently.

Kurfurst__
07-24-2008, 02:27 PM
There is one difference though - the British measured pressure as a relative unit, that is to say, compared to sea level pressure. Hence it is +25 lbs/sq. inch, or 25 lbs/sq.inch above SL air pressure (ie. above ~1 atmosphere).

The Germans, Italians, Russians, French etc. measured it in absolute terms of pressure, ie. not related to SL pressure. Germans and Italians typically expressed in ata (absolute atmosphere pressure), the Russians, and the French (who`s engine the Russians often copied btw) used Hgmm as a measurement unit.

When converting one into the each other, this has to be taken into account. Ie. +25 lbs/sq.inch is really 1 ata + whatever 25 lbs/sq.inch translates in atmospheres. It works around somewhere between 2 and 2.5 ata manifold pressure IIRC. 1.7ata translates to something like +7.

Second mistake sometimes made is comparing ata to ata, and make big conclusions about 'engine strenght' and stuff like that, since the British typically used higher manifold pressures. Firstly 1 or 2 atmospheres of pressure is a laughably 'pressure' value, less than I fill up my car`s tyres with.. if rubber in the tyre can take it, I guess an aluminium engine block with steel liners can handle that 'insane pressure' as well. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Secondly, its only a matter of choice - the British would naturally use higher manifold pressures as their engines were of typically smaller displacement so they needed to have greater air pressure (ie. more air) inside the smaller volume cylinders than in a typically larger volume German engine. Power developed is a function of amount of fuel burned, and the engine`s effiency to translate it into shaft power. They also used higher RPMs to make up for smaller displacement. The Germans OTOH did with moderate manifold pressures, and instead opted for higher and higher compression ratios. To simplify, higher compression ratios meant greater effiency, though it is not such a direct way of yielding more power out of the engine.

Different, yet parallel paths to the same goal.

Kettenhunde
07-24-2008, 02:53 PM
To simplify, higher compression ratios meant greater effiency,

And direct fuel injection.

Xiolablu3
07-24-2008, 02:56 PM
Very interesting, thanks Kurfurst.

PanzerAce
07-24-2008, 03:08 PM
Originally posted by Kurfurst__:
Second mistake sometimes made is comparing ata to ata, and make big conclusions about 'engine strenght' and stuff like that, since the British typically used higher manifold pressures. Firstly 1 or 2 atmospheres of pressure is a laughably 'pressure' value, less than I fill up my car`s tyres with.. if rubber in the tyre can take it, I guess an aluminium engine block with steel liners can handle that 'insane pressure' as well. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Secondly, its only a matter of choice - the British would naturally use higher manifold pressures as their engines were of typically smaller displacement so they needed to have greater air pressure (ie. more air) inside the smaller volume cylinders than in a typically larger volume German engine. Power developed is a function of amount of fuel burned, and the engine`s effiency to translate it into shaft power. They also used higher RPMs to make up for smaller displacement. The Germans OTOH did with moderate manifold pressures, and instead opted for higher and higher compression ratios. To simplify, higher compression ratios meant greater effiency, though it is not such a direct way of yielding more power out of the engine.

Different, yet parallel paths to the same goal.

Not to offend, but how much do you actually know about the way that ICE engines work? Your comments about the boost being laughable, to me, indicate a complete lack of knowledge. While it is true that on its own, a 25lb boost is not that much, it is a completely different story once the spark plugs fire.

And FYI, often times engines CAN'T take that kind of power. Without alot of work done ahead of time to figure out what needs to be done, running that kind of boost is a good way to put a hole through the piston if you are lucky, and to window a block if you aren't lucky.

Also, tire pressure is a (near) constant, while engines have to deal with WILDLY fluctuating internal pressures.

Additionally, your statement about higher and higher CR ratios for german engines is questionable at best. An early DB601Aa has a CR of 6.9:1, while the late model Jumo 213 has a CR of 6.5:1.

Finally, CR ratios do not mean greater efficency, it just means that the pre-spark pressure in the cylinder is higher for a given amount of boost on the engine. It is true that you can generally get more complete combustion with a higher CR, but that does not automatically equate to a higher efficiency.

Xiolablu3
07-24-2008, 03:23 PM
YOu got the wrong idea Panzerace...

He just missed a word out panzerace, he meant that his car tyre held a 'laughably small' pressure (1 or 2 atmospheres), not that Boost pressure used in fighters was 'laughably small'

Just a misunderstanding I think..http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Kurfurst__
07-24-2008, 03:32 PM
1, We are talking about aero engines, and ALL of them are supercharged to various extent, and not tinkering with your naturally aspirating car engine in the garage, using non aviation-grade fuels.

2, CR in DB engines. DB601Aa 6,9:1, DB 605A 7,5:1, DB 605D 8,5:1. Typically Merlins and Allisons run at 6:1 through the war. Specifically for the Jumo 213 there were multiple models with high and low CR.

3, "Finally, CR ratios do not mean greater efficency" its odd that first you contest that, then describe how they do actually get higher effiency (more work done in single cycle, better burning effiency), and then you deny it again claiming there may be exceptions from the rule. Also I would like to draw your attentions, that unlike car engines *CAUGH CAUGH*, aero engines typically operate a, supercharged. b, on a wide altitude band.

Undoubtedly you are way better educated about IC engines than me, so from that point on, you can also tell us why higher CR generally yields higher engine effiency in aero engines because of these circumstances.

TinyTim
07-24-2008, 04:48 PM
Avoiding to make a new thread on similar topic:

Which spitfire of the same version do you guys prefer for general air to air combat, the clipped or non-clipped sub-version?

DKoor
07-24-2008, 04:58 PM
I like 'normal' Spitfire better.
Looks cooler.

Clipped wings Spitfire may prove to be more effective, tho. It possesses excellent turn rate slightly inferior to those of normal Spit, but it is slightly better at max speed than non-clipped Spit which is a things that arguably counts more.

Ba5tard5word
07-24-2008, 05:51 PM
so...

clipped wing = higher top speed

non-clipped wing = tighter turning

???

the rather lacklustre description of the Spitfire in the Il-2 list of aircraft mentions something about the CW spits being more for low-level flying...is this true? or BS?

a little confused now... http://forums.ubi.com/images/smilies/53.gif

crucislancer
07-24-2008, 05:52 PM
Originally posted by DKoor:
I like 'normal' Spitfire better.
Looks cooler.

Clipped wings Spitfire may prove to be more effective, tho. It possesses excellent turn rate slightly inferior to those of normal Spit, but it is slightly better at max speed than non-clipped Spit which is a things that arguably counts more.

+1

I've flown the CW Spits when I had to, but usually I go for the standard version.

KrashanTopolova
07-24-2008, 06:22 PM
Originally posted by Codger1949:
Would somebody please tell me which performs better at low alt? Or which is the superior spit in whatever way?

1. Clipped winged Spits are designed for low altitude manouvreability.

2. Impossible to talk about superior aircraft in battle for even todays jet fighter pilots leave a conversation on this at some point and then begin talking about pilot ability as the decisive factor when aircraft performances are so close as to make little difference to an outcome.

However, just as the BF109G became the definitive so did the Spit 1X which could outclimb, outurn and outperform the FW190...then the war ended.

3. In my view, I would choose a p-40 down low...but not use it all the way up until the war ended.

Schwarz.13
07-24-2008, 06:46 PM
Originally posted by Kurfurst__:
1, We are talking about aero engines, and ALL of them are supercharged to various extent, and not tinkering with your naturally aspirating car engine in the garage, using non aviation-grade fuels.

2, CR in DB engines. DB601Aa 6,9:1, DB 605A 7,5:1, DB 605D 8,5:1. Typically Merlins and Allisons run at 6:1 through the war. Specifically for the Jumo 213 there were multiple models with high and low CR.

3, "Finally, CR ratios do not mean greater efficency" its odd that first you contest that, then describe how they do actually get higher effiency (more work done in single cycle, better burning effiency), and then you deny it again claiming there may be exceptions from the rule. Also I would like to draw your attentions, that unlike car engines *CAUGH CAUGH*, aero engines typically operate a, supercharged. b, on a wide altitude band.

Undoubtedly you are way better educated about IC engines than me, so from that point on, you can also tell us why higher CR generally yields higher engine effiency in aero engines because of these circumstances.

I really wish i could understand the technical 'stuff' about aero engines better!

Is there such a book as 'Aero Engines For Dummies'? http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

julian265
07-25-2008, 12:06 AM
Kurfurst, CR matters much, much more to a naturally aspirated engine than a turbo/supercharged one. It's popular knowledge that CR is directly proportional to engine efficiency... Which is true enough when comparing an NA engine to an NA engine, or one 25lb boost engine to another. However it becomes more complicated when comparing engines of different manifold pressure.

This is because it's really the *pressure at which combustion occurs at (over the duration of the burn)* that determines efficiency. Thus, you can have two engines, one NA, one supercharged, with identical efficiencies, with the supercharged engine having a much lower CR.

Raising CR raises the *peak* pressure a cylinder contains, whilst raising boost increases pressure during the whole intake and combustion cycle. Thus, to have the same efficiency, the lower boost and higher CR engine has a HIGHER peak pressure... And it's at this time that the engine is most at risk. So for the same power being generated (and efficiency), the higher peak pressures of the higher CR lower boost engine place it at more risk.

To many engine designers, it makes more sense to increase boost and decrease CR to get the best efficiency and specific power from an engine, especially when lightning fast throttle response is not much of a concern, as in aircraft.

There are obviously many, many more variables to think of when designing an engine, such as the power used in the supercharger, compared to the power used in the cylinders to compress air. I just thought I'd add to your discussion of the effect of CR.

KrashanTopolova
07-25-2008, 12:18 AM
Originally posted by Schwarz.13:


I really wish i could understand the technical 'stuff' about aero engines better!

Is there such a book as 'Aero Engines For Dummies'? http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

The only things vital to know about aircraft piston engines apart from HP are:
1. that they are more reliable than car engines; and
2. never put a car engine in an aircraft.

M_Gunz
07-25-2008, 07:23 AM
Clipped wings roll quicker. Spitfire design is not the best on rollrate.

Boost allows you to run more air and fuel through the engine up to what it can take.

And at least I'm pretty sure that during the war DB *did* keep working on increasing boost as
'a good way to get more power'.

Boost isn't the whole story on power -- there, 7 words to say what a whole paragraph and sour
grape put-down might otherwise require.

BTW, SL air pressure is 14.7 psi, +25 lbs boost is 2.7 ATA

Xiolablu3
07-25-2008, 01:31 PM
It cannot be true that high boost rates are simple to acheive.

Werent the early 109G's derated after numerous engine fires?

Hans Jochim M****illes death springs to mind as a result of attempting too high boost rates when the engine is not yet capable...

KrashanTopolova
07-25-2008, 06:11 PM
Originally posted by Xiolablu3:
It cannot be true that high boost rates are simple to acheive.

Werent the early 109G's derated after numerous engine fires?



Also aero engine reliability depends on fundamentals such as constant fuel pressure. reduction in fuel pressure leads to a poor mixture and an engine running rough. There is no boost possible there. Compression ratio won't help either. BF109G has fuel injection (perhaps earlier models also) and if it needed oil pressure management it would have needed to keep oil temp below a certain degrees (perhaps 98?) lest overheating become a problem on the ground. This was true of all high performance pistons.

Kettenhunde
07-25-2008, 07:16 PM
to a naturally aspirated engine than a turbo/supercharged one.

AFAIK, only the Germans produced a direct fuel injected aircraft engines in their fighters.

All others were naturally aspirated and subject to all the problems and limitations of that method of fuel metering.

The disadvantages of direct injection are increased complexity and cost.

The advantages of direct injection are more power. The fuel use is more efficient. Direct injection can get more power from a lower grade fuel.

http://en.wikipedia.org/wiki/Fuel_injection


Cadillac sells the CTS with both indirect and direct injection versions of its 3.6 liter V6 engine. The indirect engine produces 263 horsepower and 253 lb-ft of torque, while the direct version develops 304 hp and 274 lb-ft. Despite the additional power, EPA fuel economy estimates for the direct injection engine are 1 MPG higher in the city (18 MPG vs 17 MPG) and equal on the highway. Another advantage: Cadillac's direct injection engine runs on regular (87 octane) gasoline. Competing cars from Infiniti and Lexus, which use 300 hp V6 engines with indirect injection, require premium fuel.



http://cars.about.com/od/thingsyouneedtoknow/a/directinjection.htm

Here is the P47's R-2800 POH for example:

http://img528.imageshack.us/img528/2470/p47carbvd7.jpg (http://imageshack.us)
http://img528.imageshack.us/img528/2470/p47carbvd7.7e666b9d51.jpg (http://g.imageshack.us/g.php?h=528&i=p47carbvd7.jpg)

All the best,

Crumpp

julian265
07-26-2008, 01:29 AM
Kettenhunde, you've mixed up the method of aspiration with method of fuel metering.

Naturally aspirated = no turbo/supercharger.

You're thinking of injected vs direct injected vs carb'd, which is nothing to do with my post that you quoted.

Kettenhunde
07-26-2008, 06:34 AM
Kurfurst, CR matters much, much more to a naturally aspirated engine than a turbo/supercharged one. It's popular knowledge that CR is directly proportional to engine efficiency... Which is true enough when comparing an NA engine to an NA engine, or one 25lb boost engine to another. However it becomes more complicated when comparing engines of different manifold pressure.

This is because it's really the *pressure at which combustion occurs at (over the duration of the burn)* that determines efficiency. Thus, you can have two engines, one NA, one supercharged, with identical efficiencies, with the supercharged engine having a much lower CR.

You can see my post above to know that this not entirely true. Since all the engines we are discussing are turbo/supercharged it is also a mute point.

Fuel metering has much to do with efficiency and power production. There is a large difference between carbureted and direct fuel injection engines in terms of efficiency.

Additionally direct fuel injection is immune to many of the hazards unique to aircraft engines such as icing and unusual attitude acceleration.


Kettenhunde, you've mixed up the method of aspiration with method of fuel metering.

I apologize for misusing the term but that has nothing to do with my understanding of how it all works.


To many engine designers, it makes more sense to increase boost and decrease CR to get the best efficiency and specific power from an engine, especially when lightning fast throttle response is not much of a concern, as in aircraft.


Obviously, you are not a pilot.

http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

Instant throttle response is extremely important especially in an emergency or a dogfight. Try a botched approach at minimums and not have instant throttle response.

All the best,

Crumpp

julian265
07-26-2008, 07:37 AM
Originally posted by Kettenhunde:

You can see my post above to know that this not entirely true. Since all the engines we are discussing are turbo/supercharged it is also a mute point. I didn't think it was a moot point, and was trying to assist Kurfurst's understanding of how CR does or doesn't affect efficiency.


Fuel metering has much to do with efficiency and power production. There is a large difference between carbureted and direct fuel injection engines in terms of efficiency.

Additionally direct fuel injection is immune to many of the hazards unique to aircraft engines such as icing and unusual attitude acceleration.
Ah, I see what you're getting at. You think I was saying that efficiency depends only on what I mentioned. Did you skip over my last lines in my original post:
"There are obviously many, many more variables to think of when designing an engine, such as the power used in the supercharger, compared to the power used in the cylinders to compress air. I just thought I'd add to your discussion of the effect of CR." ??



Obviously, you are not a pilot.

http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

Instant throttle response is extremely important especially in an emergency or a dogfight. Try a botched approach at minimums and not have instant throttle response. You're absolutely right - response is definitely important, and my statement was badly worded. HOWEVER... What I was trying to get at was that instant throttle response in aircraft that we're talking about was often traded for ultimate power. Much like the compromises made with early fighter's fixed pitch props - for low or high speed operation, or the high vs low speed handling characteristics of any plane. Compromises have to be made in these areas, and throttle response vs ultimate power is one example. That said, given how fast throttle movements seem to affect even these old fighters, I'm not sure if any faster throttle response would be any aid!

Kettenhunde
07-26-2008, 08:56 AM
Hi Julian


CR does or doesn't affect efficiency.


That is a given. CR does affect efficiency. It is a fundamental concept found in the first law of thermodynamics.

Simply put, by doing more work on the gas, we increase the amount of work the gas can do.

http://wiki.answers.com/Q/How_does_compression_ratio_af...ency_and_performan ce (http://wiki.answers.com/Q/How_does_compression_ratio_affect_engine_efficienc y_and_performance)


You think I was saying that efficiency depends only on what I mentioned.

No I think you downplay the importance and the differences. That makes your post unintentionally misleading. As all of these engines were turbo/supercharged, the fuel metering methodology becomes a major factor.


You're absolutely right - response is definitely important, and my statement was badly worded. HOWEVER... What I was trying to get at was that instant throttle response in aircraft that we're talking about was often traded for ultimate power. Much like the compromises made with early fighter's fixed pitch props - for low or high speed operation, or the high vs low speed handling characteristics of any plane. Compromises have to be made in these areas, and throttle response vs ultimate power is one example. That said, given how fast throttle movements seem to affect even these old fighters, I'm not sure if any faster throttle response would be any aid!


Actually it was a large factor in design determination. It is one of the reason's we only see two turbocharged fighters in service during the war.

Most country opted for the instant throttle response of a supercharger, as the power to weight ratios especially at low density altitudes was not very good in the turbosupercharged engines.

All the best,

Crumpp

julian265
07-26-2008, 06:21 PM
Originally posted by Kettenhunde:
Hi Julian

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">CR does or doesn't affect efficiency.

That is a given. CR does affect efficiency. It is a fundamental concept found in the first law of thermodynamics.

Simply put, by doing more work on the gas, we increase the amount of work the gas can do. </div></BLOCKQUOTE> You've forgotten my first post. The condensed version of what I was saying was that combustion pressure affects efficiency, and can be substitute for higher CR. Nothing more, nothing less.


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> You think I was saying that efficiency depends only on what I mentioned.

No I think you downplay the importance and the differences. That makes your post unintentionally misleading. As all of these engines were turbo/supercharged, the fuel metering methodology becomes a major factor. </div></BLOCKQUOTE> That's you're understanding, and no one else's. I specifically stated that my comments were regarding one area only (CR and efficiency), which was previously being discussed. You could have added your comments without "correcting" mine, and extrapolating their meaning.


Actually it was a large factor in design determination. It is one of the reason's we only see two turbocharged fighters in service during the war.

Most country opted for the instant throttle response of a supercharger, as the power to weight ratios especially at low density altitudes was not very good in the turbosupercharged engines. Ok, throttle response was higher up on the list of priorities than I thought.

Kettenhunde
07-26-2008, 09:01 PM
You could have added your comments without "correcting" mine, and extrapolating their meaning.

That is kind of hard to do when I am answering your comments.

Facts are that designers are easily able to manipulate the Final Compression ratio which is your point. What you fail to point out in downplaying the higher CR is that having a high CR means we can have much lower boost pressure for the same amount of power. That means our supercharger does not require as much power to run further increasing our efficiency.

Most importantly for an aircraft engine, a high CR means better high density altitude performance at no additional weight.

All the best,

Crumpp

M_Gunz
07-26-2008, 09:17 PM
It also requires closer tolerances, doesn't it?
And that would require more maintenance in the face of wear but mostly less engines produced
and more scrap in both production and the field.

Kettenhunde
07-26-2008, 10:12 PM
Not really anymore so than having high boost levels.

Remember these are aircraft engines and as such are limited by the physics of flight. Their margins are small no matter what the motor specifics.

All the best,

Crumpp

julian265
07-27-2008, 02:00 AM
Facts are that designers are easily able to manipulate the Final Compression ratio which is your point. No, I didn't make that point, but it's a correct one. They're also easily able to manipulate boost... And once the engine is manufactured, it's much easier to change the amount of boost than the compression ratio... Which is admittedly going off on a tangent.


What you fail to point out in downplaying the higher CR is that having a high CR means we can have much lower boost pressure for the same amount of power. I have issues with the word "much". Increasing CR by a practical and safe amount yields a few percent increase in power. (see http://www.tpub.com/content/altfuels02/2834/28340011.htm , or your favourite thermodynamics book) If you've increased power by 5% by increasing CR, you've also increased the likelyhood of detonation much more than if you had obtained the increase with around 5% extra boost. This is because a 5% increase in power requires an increase in CR of around 2 (eg, 6 to 8), for the sort of engine's we're talking about, and this is a LARGE increase by anyone's CR standards, creating much larger *peak* cylinder pressures than would be obtained with the 5% increase in boost. In fact, by changing CR from 6 to 8, we've increased our peak cylinder pressure by around 33%, compared to only 5%, for that much more boost. That's a large increase in risk for 5% power.

Also, I will point out that as you proportionately increase CR, the increase in power becomes smaller quite quickly, unlike the same proportionate increases in boost.


That means our supercharger does not require as much power to run further increasing our efficiency. True, but now it's the pistons doing more compression work... Which is definitely not 'free'.

julian265
07-27-2008, 03:11 AM
To clarify my opinion... I DON'T think that "high boost, low CR is always the answer". The above post merely corrects what I see as misleading information.

Both the RR and DB engines must have worked pretty well, each developed with differing ideals and supply limitations.

Kettenhunde
07-27-2008, 06:23 AM
Increasing CR by a practical and safe amount yields a few percent increase in power.

Funny the trend is simple. Increase CR and you increase efficiency.

http://img155.imageshack.us/img155/9839/thermalefficiencybt6.jpg (http://imageshack.us)
http://img155.imageshack.us/img155/9839/thermalefficiencybt6.5817c21b65.jpg (http://g.imageshack.us/g.php?h=155&i=thermalefficiencybt6.jpg)


Compression ratio, ignition timing, thermal coatings, plug location and chamber design all affect the thermal efficiency (TE). Low compression street engines (smog motors) may have a TE of approximately 0.26. A racing engine may have a TE of approximately 0.34. Because these numbers are relatively small, at first glance there may not seem to be much difference between the street engine and the racing engine. However, when you grind out the math (.34 - .26 / .26), the racing engine produces about 30% more power because of the higher TE.

Finding little improvements to the TE can end up as a significant improvement to the final horsepower that the engine produces.


http://www.auto-ware.com/combust_bytes/eng_sci.htm

You fail to put it all together and clearly do not understand that small gains pay large dividends in terms of power.


To clarify my opinion...

Your opinion is wrong and once more you push it as fact.


True, but now it's the pistons doing more compression work... Which is definitely not 'free'.


You are referring to the mechanical efficiency. Certainly higher compression leads to greater friction.

However your post is misleading as once again the largest detractor to Mechanical Energy is the rpm.


Mechanical efficiency is effected by rocker friction, bearing friction, piston skirt area, and other moving parts, but it is also dependent on the engine's RPM. The greater the RPM, the more power it takes to turn the engine. This means the faster the engine runs the more the ME drops. Often times the ME is expressed in terms of friction horsepower. Or in other words, how much horsepower is needed just to overcome the friction.

http://www.auto-ware.com/combust_bytes/eng_sci.htm

The German designers used direct fuel injection to increase their volumetric efficiency, CR to increase Thermal efficiency, and lower rpm as well as devices such as hydraulic couplings to improve mechanical efficiency.

Facts are all sides had the best and brightest engineering minds of their societies hard at work. There is simply very little to choose between the designs.

All the best,

Crumpp

julian265
07-27-2008, 07:58 AM
Funny the trend is simple. Increase CR and you increase efficiency. Lol. Apparently I shouldn't have bothered writing that post at all.


Compression ratio, ignition timing, thermal coatings, plug location and chamber design all affect the thermal efficiency (TE). Low compression street engines (smog motors) may have a TE of approximately 0.26. A racing engine may have a TE of approximately 0.34. Because these numbers are relatively small, at first glance there may not seem to be much difference between the street engine and the racing engine. However, when you grind out the math (.34 - .26 / .26), the racing engine produces about 30% more power because of the higher TE.

Finding little improvements to the TE can end up as a significant improvement to the final horsepower that the engine produces.
Sure. So far I've restricted myself to dealing with the topic of boost and compression ratio, and their effect on efficiency, you know, to show their individual effects by limiting variables, which is in line with the original post I responded to.


You fail to put it all together and clearly do not understand that small gains pay large dividends in terms of power. It's you that fails to read posts and points as they were intended. I'm not trying to put it all together. You'd need to write a book or two to do that.


Your opinion is wrong and once more you push it as fact.[quote] Which one exactly? Each response of yours seems to diverge into different topics, expanding the context of my posts beyond their intended scope, and then claim that I've left this or that out. If you could for once discuss a post without doing that, the discussion would not degenerate, and might be interesting and concise for other readers.

[quote]You are referring to the mechanical efficiency. Certainly higher compression leads to greater friction.
However your post is misleading as once again the largest detractor to Mechanical Energy is the rpm. The point to which you responded was that whether the compression work is done by the supercharger, or by the pistons, it's still work that detracts from shaft power. (without going into the costs/benefits of each)


Mechanical efficiency is effected by rocker friction, bearing friction, piston skirt area, and other moving parts, but it is also dependent on the engine's RPM. The greater the RPM, the more power it takes to turn the engine. This means the faster the engine runs the more the ME drops. Often times the ME is expressed in terms of friction horsepower. Or in other words, how much horsepower is needed just to overcome the friction.

The German designers used direct fuel injection to increase their volumetric efficiency, CR to increase Thermal efficiency, and lower rpm as well as devices such as hydraulic couplings to improve mechanical efficiency.

Facts are all sides had the best and brightest engineering minds of their societies hard at work. There is simply very little to choose between the designs. Absolutely.

Anyway, I'll be interstate for the next three days and will only have web access if it's free at the hotel. Have fun!

Kettenhunde
07-27-2008, 08:17 AM
Lol. Apparently I shouldn't have bothered writing that post at all.

I don't think it increased your credibility if that is what you mean.

Good luck on your trip.

KrashanTopolova
07-27-2008, 06:06 PM
This discussion seems to have concentrated on engine performance and missed comparative efficiences from airmanship. In some circumstances varying prop pitch achieves more than boost in terms of greater instant acceleration. WEP was used only for 5 seconds or so as far as I can ascertain (P-47 pilot) and this was more likely used going downhill. It gave that edge in closing a gap in a window of chance.

M_Gunz
07-27-2008, 06:14 PM
What are you smokin?

KrashanTopolova
07-29-2008, 09:34 PM
Originally posted by M_Gunz:
What are you smokin?

Lately I've been somkin La%'s, BF109's and Zeros...what have you been smokin'?

But seriously...back to the first question: The Mark VIII Spit was meant to follow in chronological order but the new presence of the FW190 forced alterations to the production line of the MkV. So the next service Spit became the Mark IX before there was a MkVIII in operational service.

The FW190 was probably the reason why boost was introduced into the MkIX.

The MkV had a 1440 HP Merlin 45. Both the VIII and the IX were powered by a 1740HP Merlin 63 with two-stage two-speed supercharger. Only the IX kept a MkV airframe and had added to it WEP boost.

In some pilots' view the VIII was better.

Some Spit pilots liked the MkVIII for its own characteristics and so there are competing loyalties.

The thing to notice about WWII Veteran pilots who flew a few different types in their operationl flying is that in spite of performance differrences between their aircraft, all aircraft they flew were hardly ever disparaged. They got the best out of whatever aircraft they were given.

Example, some Spit pilots would never agree that a P-40 could turn with it...but other pilots say it could if flown properly and that it could roll better than the Spit and the Mustang.

ImpStarDuece
07-30-2008, 01:17 AM
Originally posted by KrashanTopolova:
The Mark VIII Spit was meant to follow in chronological order but the new presence of the FW190 forced alterations to the production line of the MkV. So the next service Spit became the Mark IX before there was a MkVIII in operational service.



Partially true.

The pressurised Mk VII was supposed to precede the Mk VIII. The design work on the Mk VII/VIII began in early 1941, as an extension of the Mk III airframe redesigned to fit the longer two stage Merlin then in development.

The Mk IX was essentially a Mk V lash up with a Merlin 61 at the front end and rearranged internal cooling.



The FW190 was probably the reason why boost was introduced into the MkIX.

??

This sentence makes little sense. What do you mean by "boost". The FW 190 was the reason that the RAF hurried the introduction of the two stage two speed Merlin engine.



The MkV had a 1440 HP Merlin 45. Both the VIII and the IX were powered by a 1740HP Merlin 63 with two-stage two-speed supercharger. Only the IX kept a MkV airframe and had added to it WEP boost.

"WEP boost" is a misnomer. No wartime Merlins had a true war emergency power setting, like we think of in game terms. However, they could be run at very high boost pressures for limited periods. The Mk I had an ˜emergency boost cut-out' setting.

The initial engine fitted to the Spitfire Mk IX was the Merlin 61, which produced 1,565 hp at +15 ½ lbs boost rating. Later on the more powerful Merlin 63A and Merlin 66 were introduced, producing the LF Mk IX. Theses engines were rated at 1,720 hp at 18 lbs of boost.

Merlin engine power is highly dependent on the pressure the engine is operated at. The Merlin 45 started out producing 1,185 hp at +9 lbs boost, 1,310 hp at +12 lbs and was eventually cranked up to 1,515 hp at +16 lbs boost, later in the war as higher power was needed to compete with faster and faster opposing fighters. So, in 1941 you might of faced a Mk V with less than 1,200 hp, but, with a few engine mods the same aircraft could have had more than 1,500 hp on tap about 18 months later.


Example, some Spit pilots would never agree that a P-40 could turn with it...but other pilots say it could if flown properly and that it could roll better than the Spit and the Mustang.

The P-40 did roll better than the early Spitfires, the RAE made a point of this in their comparison between the fighters. Later Spitfires, with clipped wings and metal ailerons would be superior though.

M_Gunz
07-30-2008, 02:00 AM
Originally posted by KrashanTopolova:
This discussion seems to have concentrated on engine performance and missed comparative efficiences from airmanship. In some circumstances varying prop pitch achieves more than boost in terms of greater instant acceleration.

Except for many early war planes, prop pitch is varied by the plane itself through either
electric or hydraulic automatic control. Most planes in IL2 have some form of CSP, Constant
Speed Prop.


WEP was used only for 5 seconds or so as far as I can ascertain (P-47 pilot)

Try closer to 5+ minutes. None less than 3 minutes if they had WEP at all.

I saw your post there and another from about the same time that I was wondering, huh-whaaaa?

Kettenhunde
07-30-2008, 05:03 AM
No wartime Merlins had a true war emergency power setting, like we think of in game terms.


That is true War Emergency Boost!

http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

That is all most of them are in fact. While there are difference nomenclatures for it as well as the multiple types of methods of increasing knock limiting performance, the most common "boost" increase is just a simple manifold pressure increase and fuel burn increase.

For example, Erhöhte Notleistung fur Jager in the BMW801D2 was just a simple manifold pressure increase.

All the best,

Crumpp

julian265
07-30-2008, 07:51 AM
I don't think it increased your credibility if that is what you mean.

No, I meant that it's just another post that you have avoided discussing the contents of, instead calling it wrong, and then adding some facts which are outside of the scope of the points which you are contesting. I think I've seen this method before.

In my FIRST post I wrote this:

"There are obviously many, many more variables to think of when designing an engine, such as the power used in the supercharger, compared to the power used in the cylinders to compress air. I just thought I'd add to your discussion of the effect of CR."

Our discussion is going nowhere, and since you have decided to ignore the above paragraph multiple times, whilst continuously calling me wrong, I can only deduce that your motives for posting in this thread are different to mine.

That's it from me.

Kettenhunde
07-30-2008, 09:06 AM
I just thought I'd add to your discussion of the effect of CR."


And you have Julian. There are no hard feelings or animosity. It's been a good discussion IMHO.

Don't take things so personally.

In this statement:


Julain says:
Increasing CR by a practical and safe amount yields a few percent increase in power.

You have confused thermal efficiency with power. While increasing CR represents a small increase thermal efficiency, that small increase represents a much larger proportionally increase in power.

That is what I meant by you did not put it all together. That inability to "put it together" has influenced your opinion of the effect of CR.

All the Best,

Crumpp

Kurfurst__
07-30-2008, 01:19 PM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">You could have added your comments without "correcting" mine, and extrapolating their meaning.

That is kind of hard to do when I am answering your comments.

Facts are that designers are easily able to manipulate the Final Compression ratio which is your point. What you fail to point out in downplaying the higher CR is that having a high CR means we can have much lower boost pressure for the same amount of power. That means our supercharger does not require as much power to run further increasing our efficiency.

Most importantly for an aircraft engine, a high CR means better high density altitude performance at no additional weight.

All the best,

Crumpp </div></BLOCKQUOTE>

Crumpp had, in an elegantly brief manner expressed in a few sentences what I was struggling to describe.

Simply to put: higher CR means slightly higher output at ALL altitudes, and it decreases fuel consumption for given power output - this translates to less fuel needs to be carried, less supercharging, and cooling capacity required. All of this translates to savings in mass and drag.

stathem
07-30-2008, 01:30 PM
But unless you have your spark plug technology sorted out it may result in you blowing holes in your piston crowns and having to de-rate the engine... http://forums.ubi.com/images/smilies/shady.gif

Kurfurst__
07-30-2008, 01:40 PM
True. It happened to the DB 605A, it burned through the pistons like mad when it was introduced, although *this* problem was solved quickly. Its a less straightforward way than directly 'boosting' an engine, and the pitfalls are different. I tend to believe though that in the long run, its the easier path.

KrashanTopolova
07-30-2008, 05:45 PM
[QUOTE]Originally posted by M_Gunz:

Except for many early war planes, prop pitch is varied by the plane itself through either
electric or hydraulic automatic control. Most planes in IL2 have some form of CSP, Constant
Speed Prop.

irrelevant if CSP for if CSP the same tactic is used (a certain manouvre) KT


Try closer to 5+ minutes [use of WEP]. None less than 3 minutes if they had WEP at all.


When 5 seconds was mentioned I was quoting USAAF P-47 Ace Gabrinsky. KT

KrashanTopolova
07-30-2008, 05:59 PM
Originally posted by ImpStarDuece:


[QUOTE]
The FW190 was probably the reason why boost was introduced into the MkIX.

??

This sentence makes little sense. What do you mean by "boost". The FW 190 was the reason that the RAF hurried the introduction of the two stage two speed Merlin engine.

----------------------
On a Mkv airframe? They were worried about something in the FW190 performance but I don't think it was a need for supercharger superiority that made them reach quickly for a MkV airframe. The RAF wanted a Spit that would outclimb, outdive, out-anything the FW190. They installed 25lb boost to try and achieve that superiority over the FW190. They left it off the MkVIII (which does not necessarily mean the VIII was inferior to the IX.
It should be kept in mind that the RAF always wanted an interceptor that could reach high altitudes quickly and operate at high altitudes efficiently.

The rest of your post contains some interesting facts. KT

KrashanTopolova
07-31-2008, 07:10 PM
M-Gunz...I think we are talking about different flying: You about mission flying (egress, ingress, climb rate, dive rate etc): Me about dogfighting using all available instantaneous performance variables on the aircraft.

I don't want to spell out for others as a free ride what I've learned through many hours on il-2...one would rather others discover things themselves right?

Of course varying PP can increase instantaneous acceleration above the performance that 'boost' was meant to instill in the aircraft especially when I purposely mentioned 'in some circumstances'.

As for 5 seconds...how long do you want a dogfight to go on for...it's not incredible that Grabinsky only needed 5 seconds having set up the attack. 5 seconds can be an eternity to win while 5 minutes can be a ridiculous amount of time to lose the fight (no word games intended).

Finally a word about il-2. Your factsheet as presented is in fact modelled in the game (rpm and prop speed out of sync.). In some circumstances this only amounts to an overheating signage; in other circumstance you hear the engine over-rev. Well done to Oleg for it gives further clues on using CEM properly.

M_Gunz
08-01-2008, 02:31 AM
Those are historic docs on how the actual planes ran.
The POH's give FIVE MINUTES at maximum, what we call WEP.
Some ran longer, in fact at high alt in game you might want to check time to overheat the P-47.
There's been more than a couple threads on exactly that with far more documents posted.

The man's name was Gabresky unless you're talking about someone relatively unknown.
You might want to check your memory before playing at arguing.

You're down to pleading over 5 seconds being a long time when it takes over 20 to turn a 360.
You're down to making up your own reality and trying to con me into some kind of social game.
Awwww, c'mon man! It -seems- to me that.... oh I remember what Grabinsky said.

I've shown you the docs and you come back with that. When/if the P-47 fans see what you're
trying to say you'll get to see more, I am sure.

As for my part in this, I'm turning the handle and getting off the pot. By-yeeeeeeeeee.

Xiolablu3
08-01-2008, 05:01 PM
Just to clarify things in everyday language, WEP isnt an exact science, an engine wouldnt suddenly give up as soon as you reached over 5 minutes.

5 minutes was the maximum you could run before there was a CHANCE of damaging the engine.

Obviously some pilots being chased by enemy planes would use the boost for longer periods, and there would most likely be no problem.

When you run at max boost/WEP then you are shortening the life of the engine. Its quite possible that a brand new, well built engine could run well over 5 minutes boost, probably a LOT longer, as MAx says. However its a requirement to strip the engine down and test it after a certain period of WEP use, so it is certainly not desirable to use it for long periods.

The way Rolls Royce improved reliablilty was to take a random engine from every batch made and run it at full power until it failed. Then they would strengthen that part and do it all over again with another batch. This resulted in an extremely reliable engine.

Imagine it like overclocking a CPU. SOme CPU's run for years after being overclocked. SOme will burn out.

KrashanTopolova
08-03-2008, 06:05 PM
M_Gunz...if we as pilots think it takes 20 seconds to turn 360 we will reach for WEP if we have it...if fighter pilots don't have it they will come up with another manouvre to be at the same desired position 360 degrees away in 3 dimensional space in (maybe?) 5 seconds (think steep diving turn with rudder, radius, zoom climb => greater speed than WEP performance).

Xiolablu3. mentions the tactic or using WEP to escape with speed. I was talking of needing WEP for 5 seconds to close a deflection gap on a fast-moving target being caught on a transect or tangent. Merging is a vital technique for even today's fighter pilots (another reason to get TrackIR).

M_Gunz
08-04-2008, 02:49 AM
Originally posted by KrashanTopolova:
This discussion seems to have concentrated on engine performance and missed comparative efficiences from airmanship. In some circumstances varying prop pitch achieves more than boost in terms of greater instant acceleration. WEP was used only for 5 seconds or so as far as I can ascertain (P-47 pilot) and this was more likely used going downhill. It gave that edge in closing a gap in a window of chance.

P-47 WEP was used for 5 minutes straight in CLIMB TESTS without damaging the engines.
That is the WORST situation to run full out as the speed is low which causes less air to be
forced through the radiator.

You: WEP was used only for 5 seconds or so

WEP was used in combat more often to get the H away from a bad situation. Breaking the wire
required explaining back at home why your plane was gonna be tied up having the engine checked.

Sometime learn the turn times of these planes and BTFW if you can 360 in 5 seconds then you
don't need WEP for 5 seconds to close a deflection shot -- how about just QUIT THE EXCUSES
AND EVASIONS, the "I didn't mean what I wrote" routine is nothing but that.

P-47 had 5 minutes WEP during climb without even using water injection. On level high speed
runs it could go more as, and I've pointed this out already, has been debated here more than
once before.

Anybody got a plunger? This floater won't flush!

Buzzsaw-
08-04-2008, 03:03 PM
Salute

We always get the same claims from certain posters claiming the German side had equivalent methodology re. gaining horsepower increases.

Anyone who bothers to do the slightest research will understand that the Allied, in particular, the British engines were far more efficient than the Germans.

All one has to do is to look at the displacments of the British engines and the horsepower they produced, versus the displacement of the German engines and the horsepower they produced.

The Merlin 60 series of engines displaced 27 liters, and in the final models, produced 2200 hp at +27 boost on British 100/150 octane fuel, although the RAF decided to stay with 2000 hp on +25 because it was felt the higher output was not nessesary. Power to weight ratio was 1.21 hp/lb for the engine.

The Daimler Benz 605 series displaced 35 liters and produced in the final versions, 1800 hp. Attempts to up that to 2000 hp by using C3 fuel (96 octane) were discontinued due to lack of the fuel and engine reliability issues. Power to weight ratio was 1.02 hp/lb.

This was a function of the large scale availability of higher octane fuels on the Allied side, and the lack of it on the German side. Higher octane allows for a larger volumn of compressed air/gas mixture to be forced into the compression chamber, without the fear of detonation, or premature ignition of the fuel/air mixture.

The smaller British engines also had a higher allowable rev limit, due to the smaller reciprocating mass of the pistons/rods, etc. The Merlins had a rev limit of 3000 rpm, compared to 2750 or 2800 rpm for the Daimlers. Higher rpm = higher horsepower.

The most efficient aircraft piston engine of WWII was the Napier Sabre which equipped the Typhoon and Tempest and which was an H pattern 24 cylinder design of 36 liters displacement. Most of the inline aircraft engines of the time, including the Merlin and DB605 series, were 12 cylinder V designs. Because the pistons and rod assemblies on the Sabre were half the size of other contemporary engines, rev limits were much higher.

The Sabre V produced 2850 hp at +13 boost and 3850 rpm and equipped the last serials of the Tempest V. Power to weight ratio was 1.29 hp/lb. (This engine does not equip the Tempest we have in the game, it has a little produced, early model of the Sabre, the IIa, putting out only 2180 hp)

Postwar, the Sabre VII produced an astonishing 3800 horsepower at 3850 rpm. Nothing else has come close.

Most high performance modern reciprocating piston engines follow the British Aerial engine example, of a small displacement high revving engine combined with very high octane fuels and forced air using superchargers and turbochargers. This is the pattern in Formula 1.

KrashanTopolova
08-04-2008, 08:29 PM
Originally posted by M_Gunz:
Sometime learn the turn times of these planes and BTFW if you can 360 in 5 seconds then you
don't need WEP for 5 seconds to close a deflection shotflush!

Exactly! (KT)

Please M_Gunz no need for screaming capitalisation: calm blue ocean...calm blue ocean...

KrashanTopolova
08-04-2008, 08:35 PM
Originally posted by Buzzsaw-:
Salute

...Most high performance modern reciprocating piston engines follow the British Aerial engine example, of a small displacement high revving engine combined with very high octane fuels and forced air using superchargers and turbochargers. This is the pattern in Formula 1.

and was this the beginning of the end of ultimate propellor efficiency (even after 5 blades)?...and maybe even the end of the need for WEP? (although perhaps I shouldn't go so far as to disturb the peace with such a suggestion...though Frank Whittle might agree with me that airmanship is what counts even on the new jet mounts).

WTE_Galway
08-04-2008, 09:36 PM
Originally posted by Buzzsaw-:
Postwar, the Sabre VII produced an astonishing 3800 horsepower at 3850 rpm. Nothing else has come close.


Hence the Seafury, awesome plane that still wins unlimited at Reno occasionally.

If the Seafury had made it into IL2 it would probably be the plane of choice for many online jocks.

Buzzsaw-
08-04-2008, 11:35 PM
Originally posted by WTE_Galway:

Hence the Seafury, awesome plane that still wins unlimited at Reno occasionally. If the Seafury had made it into IL2 it would probably be the plane of choice for many online jocks.


Actually the Seafury, although related to the Tempest II, had the Bristol Centaurus Radial engine, not a Sabre. It was still a nice plane. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

http://upload.wikimedia.org/wikipedia/commons/b/b8/SeaFury_launch.jpg

But all radial engines, because they are aircooled, and thus require more piston clearance for expansion, produce less horsepower per cubic inch, although they do save weight by not having the liquid cooling apparatus and jackets on the cylinders.

WTE_Galway
08-05-2008, 01:27 AM
Originally posted by Buzzsaw-:

Actually the Seafury, although related to the Tempest II, had the Bristol Centaurus Radial engine, not a Sabre. It was still a nice plane. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif



I stand corrected. I refered back to the article I was thinking of and turns out it was actually the second prototype of the Fury that was mentioned as using the Sabre VII (achieving in excess of 770 kmh) you are quite right the Seafury was a Centaurus.

Kurfurst__
08-05-2008, 01:56 AM
Originally posted by Buzzsaw-:
Salute

We always get the same claims from certain posters claiming the German side had equivalent methodology re. gaining horsepower increases.

Anyone who bothers to do the slightest research will understand that the Allied, in particular, the British engines were far more efficient than the Germans.

All one has to do is to look at the displacments of the British engines and the horsepower they produced, versus the displacement of the German engines and the horsepower they produced.

The Merlin 60 series of engines displaced 27 liters, and in the final models, produced 2200 hp at +27 boost on British 100/150 octane fuel, although the RAF decided to stay with 2000 hp on +25 because it was felt the higher output was not nessesary. Power to weight ratio was 1.21 hp/lb for the engine.

The Daimler Benz 605 series displaced 35 liters and produced in the final versions, 1800 hp. Attempts to up that to 2000 hp by using C3 fuel (96 octane) were discontinued due to lack of the fuel and engine reliability issues. Power to weight ratio was 1.02 hp/lb.

This was a function of the large scale availability of higher octane fuels on the Allied side, and the lack of it on the German side. Higher octane allows for a larger volumn of compressed air/gas mixture to be forced into the compression chamber, without the fear of detonation, or premature ignition of the fuel/air mixture.

The smaller British engines also had a higher allowable rev limit, due to the smaller reciprocating mass of the pistons/rods, etc. The Merlins had a rev limit of 3000 rpm, compared to 2750 or 2800 rpm for the Daimlers. Higher rpm = higher horsepower.

The most efficient aircraft piston engine of WWII was the Napier Sabre which equipped the Typhoon and Tempest and which was an H pattern 24 cylinder design of 36 liters displacement. Most of the inline aircraft engines of the time, including the Merlin and DB605 series, were 12 cylinder V designs. Because the pistons and rod assemblies on the Sabre were half the size of other contemporary engines, rev limits were much higher.

The Sabre V produced 2850 hp at +13 boost and 3850 rpm and equipped the last serials of the Tempest V. Power to weight ratio was 1.29 hp/lb. (This engine does not equip the Tempest we have in the game, it has a little produced, early model of the Sabre, the IIa, putting out only 2180 hp)

Postwar, the Sabre VII produced an astonishing 3800 horsepower at 3850 rpm. Nothing else has come close.

Most high performance modern reciprocating piston engines follow the British Aerial engine example, of a small displacement high revving engine combined with very high octane fuels and forced air using superchargers and turbochargers. This is the pattern in Formula 1.

http://www.sorozatjunkie.hu/wp-content/uploads/2008/02/blind-justice-poster.jpg

M_Gunz
08-05-2008, 03:09 AM
Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
Sometime learn the turn times of these planes and BTFW if you can 360 in 5 seconds then you
don't need WEP for 5 seconds to close a deflection shotflush!

Exactly! (KT)

Please M_Gunz no need for screaming capitalisation: calm blue ocean...calm blue ocean... </div></BLOCKQUOTE>

No need for the Tagert-style twist and turn the whole point, never wrong rhetoric either.

P-47 had in the worst case 5 minutes WEP.

Bremspropeller
08-05-2008, 03:17 PM
Your so-called "efficiency" doesn't mean much.

What counts is thrust output, not how many HP can be delivered by how many litres of engine.

BTW: efficiency should rather be used in relation to fuel-consumption.
Nobody would agree that the Sabre is an "efficient" engine, feeding 24 cylinders, and apart from that, randomly breaking down every once in a while.

HP doesn't mean much comparing a/c, THRUST delivered by the airscrew does. Of course more HP and more torque are always nice, but there are limits.
The airscrew's tips should not enter supersonic flow for a couple of reasons. Just increasing RPM as stated by you would make you run against that hard max RPM-limit. Nothing gained.

Aero-engines in relation with airscrew-thrust is a bit more than just adding HP numbers.

Kettenhunde
08-05-2008, 03:32 PM
That is absolutely correct Bremspropeller.

Power to weight is the most important characteristic of an aircraft engine.

http://img504.imageshack.us/img504/6656/powertoweightjr3.jpg (http://imageshack.us)
http://img504.imageshack.us/img504/6656/powertoweightjr3.4c6704d2c4.jpg (http://g.imageshack.us/g.php?h=504&i=powertoweightjr3.jpg)

All the best,

Crumpp

stathem
08-05-2008, 04:19 PM
Originally posted by Bremspropeller:

The airscrew's tips should not enter supersonic flow for a couple of reasons. Just increasing RPM as stated by you would make you run against that hard max RPM-limit. Nothing gained.



Nonsense. Ever heard of changing the Reduction gear ratio?

Bremspropeller
08-05-2008, 04:51 PM
Sure I have.

He was talking of RPM, not of torque.

KrashanTopolova
08-05-2008, 05:59 PM
In response to the point made by Bremspropellor and Kettenhunde:

In the search for a best fighter Republic started the P-47 out as a small to average size fighter but it ended up becoming the largest (its final weight equivalent to 2 BF109s). Obviously, power to weight ratio had to be of prime importance if the prototype was getting heavier in the development process. In the search for thrust it included WEP (water injection) but appears to have combined it with paddle props as a necessary combination to achieve maximum thrust.

When I refer back to Grabesky (thanks M_Gunz) I will transcribe what he said and post it. Meanwhile, he was quite adamant (with an air of dismissiveness) that the P-47 was more than a match for the BF109 and FW190. Republic even developed a P-47 with enough thrust to try and mix with the Me-262.

Eventually the Allies came to know that the prop and piston plane was obsolete in terms of combat thrust but not before much experimentation with props and engines all of which was in order to develop more thrust.

M_Gunz
08-05-2008, 05:59 PM
Engine rpm as opposed to prop rpm, what Stathem said is the crux.

Kettenhunde
08-05-2008, 06:47 PM
The P47's size and weight was a product of the turbocharger technology.

http://img171.imageshack.us/img171/4396/p47superchgnr7.jpg (http://imageshack.us)
/img171/p47superchgnr7.jpg/1/w400.png (http://g.imageshack.us/img171/p47superchgnr7.jpg/1/)

M_Gunz
08-05-2008, 08:44 PM
Exactly. There was a change of concept and total redesign involved.

www.aviationhistory.com (http://www.aviation-history.com/republic/p47.html)


A contract was awarded by the USAAC in November 1939, and for an even lighter XP-47A, but as intelligence was coming back from the war in Europe, it was becoming apparent that the performance goals of the XP-47 program were already inadequate. The USAAC issued new requirements which included:

1. Airspeed of 400 mph at 25,000 feet.
2. Armament of six .50 caliber machine guns, preferably eight.
3. Armor plating to protect the pilot.
4. Self sealing fuel tanks.
5. A minimum of 315 gallons of fuel.

The USAAC notified Kartveli that the XP-47A and the XP-44 Rocket contracts were canceled, since P-43/XP-44 airframe was to small to meet the new requirements.

Buzzsaw-
08-05-2008, 09:09 PM
Originally posted by M_Gunz:

The man's name was Gabresky...

Gabreski. American born, Polish heritage.

http://img129.imageshack.us/img129/3729/5610ez0.jpg

He's the guy in the middle. The others are native Poles, he flew with them in the RAF for a while, then after he was assigned to the USAAF, they joined him in the 56th F.G. and flew the Thunderbolts because the Spits they had in the RAF were too shortrange for them to be able to get good chances to kill Germans.

M_Gunz
08-06-2008, 01:17 AM
very good

Now we know where at least 6 of the USAAF's hotter pilots came from!

Jaws2002
08-06-2008, 01:39 AM
Originally posted by KrashanTopolova:
Republic even developed a P-47 with enough thrust to try and mix with the Me-262.




Hardly....

Quote from the article "Watson's Wizzers"


"The next thing I noticed was the speed. Raw speed, exhilarating speed. Smooth speed. Unbelievable speed. It seemed effortless. My flight was held to low altitude, so I had the ground as a reference. This was something I had never experienced in the P-47 Thunderbolt, and it was impressive."



"The Me 262 was smooth, quiet, and very responsive to the controls compared to the P-47 I had been flying for about a year. I had also flown a P-40 in the States, and the Me 262 was even better than that.

The plane was easy -- and a pleasure -- to fly. Because of its high speed, I found myself going through my maps quickly to keep pace with the distance covered over the ground. ....


I was amazed at how quick it was and immediately noticed the smoothness of handling, compared to the P-47. The control reaction was seemingly instant, and the rate of acceleration on takeoff was quite impressive. It seemed that the plane just wanted to fly. When I reduced the throttles for landing, I remember thinking "won't this thing ever slow down?" It was truly love at first flight."

"The runway was damp from a light misting that had come and gone for most of the morning. This made for an impressive display as the jet blast kicked up long rooster tails in their wake. Hillis' jet experienced a problem while retracting the landing gear, but Strobell and Holt commenced a series of high speed, low-level passes over the runway. Strobell then initiated a series of rolls over the field.

It was the first time that anyone on the team had occasion to put the machine's true capabilities to the test, and Strobell found the 262 refreshingly up to the task."

M_Gunz
08-06-2008, 07:44 AM
Only too true, Jaws. Buuuuuuut as we all know there were "rule bending" exceptions.

A P-47 through a long hard dive could jump an Me-262 slowed down for landing approach.
So could a P-51, late mark Spit, Tempest, etc, etc.

All the end of war fast props were very close in top speed. This was due to prop limits.
Nobody had a magic prop fighter to begin to match the 262 in combat though there was always
the lucky shot possible. You can get that in an I-153 or other 30's biplane against a 109F
too but that's not to say any of those was other than fodder in such a fight.

Apparently any little exception is to become a springboard for fantasy take-offs.
I'm still waiting on the 5 second WEP _limit_ for P-47's. So far it's a "you know" thing.
But then "you know" the pilot's were somehow able to adjust prop pitch to achieve big, too.

Buzzsaw-
08-06-2008, 12:25 PM
Salute

Johannes Steinhoff, who flew 262's at the end of the war, said what he feared the most was seeing P-47's above him. The reason was their very high allowable dive speed, and their tremendous dive acceleration. The later Bubble top P-47's with dive brakes had an allowable dive speed of 550 mph, higher than any other prop fighter. Since the 262 had a max. speed of 540 mph, you can see that the P-47's could catch a lower 262. The P-47 also maneuvered well at high speeds.

As far as maneuverability at medium and low speeds, the 262 was not a very maneuverable aircraft compared to a P-47, the Thunderbolt could easily outturn the jet. The 262 had a nicely coordinated set of controls for high speed flight, but in any kind of a dogfight, it would be outclassed. Of all the WWII era jets, the 262 was the poorest maneuvering, behind the Meteor, P-80 and He-162.

M_Gunz
08-06-2008, 12:48 PM
P-47 might keep 550mph in a straight dive and certainly a steep one, depending on alt,
but that's going to change quickly if that first pass misses.

262 doesn't rely on dive to run 540 and the speed is not by the power limit of the plane.

Steinhoff seems to have lived through experiencing such fear.

JtD
08-06-2008, 01:41 PM
The 550 limit for the 47 is IAS, the 540 for the 262 TAS, which makes the 47 in a dive at altitude considerably faster than a 262 in level flight.

Most successful evasive of the 262 was a shallow climb, because a shallow dive made it easier for Allied prop fighters to catch up with them.

Didn't follow the topic so if this statement was off, I'm sorry.

luftluuver
08-06-2008, 01:42 PM
The Me262 manual says <span class="ev_code_YELLOW">950kph/590mph</span> for the highest permissible dive speed.

That is 40mph higher than the P-47's max dive speed.

Kettenhunde
08-06-2008, 04:11 PM
Ever heard of changing the Reduction gear ratio?


Which is a technique of keeping the propeller below the mach limited rpm as I understood Bremspropeller to be refering to by "max-rpm".

All the best,

Crumpp

Kettenhunde
08-06-2008, 04:13 PM
Buzzsaw,

Do you the nickname JG26 gave the 56th FG P47's?

Nicht-Einmischer.

All the best,

Crumpp

KrashanTopolova
08-06-2008, 06:21 PM
Originally posted by Buzzsaw-:
Salute

Johannes Steinhoff, who flew 262's at the end of the war, said what he feared the most was seeing P-47's above him...

Steinhoff nearly got cleaned up by a late model Yak on a test mission over the Oder before the war ended. He probably used his speed to get away (it would have been a close chase by a Yak). He planned the mission to try and convince Herr Hitler (now a bit shaky) to use the Schwalbe as a fighter rather than a bomber. Steinhoff's concern was needing a fighter to intercept the Allied bombers killing his civilian people. He was exhilarated by the Me-262s speed and that is the only mention he gives it apart from the lumbering, terminable takeoff roll. He may have had visions of diving through formations of bombers rather than using the extremely well-armed Me-262 primarily as a dogfighter (my speculation). His wingman had trouble controlling his Me-262 and keeping up with him on the mission. Steinhoff came back to base with a victory over a low flying Schturmovik.

The quoted article posted above departs from other pilot reports that the Me-262s acceleration on takeoff took 'forever'. The same also applies when airspeed is lost in the Me-262. There is no comparison to the instantaneous acceleration which the P-47 had (and was designed to have with it's supercharging, WEP and paddle props). And of course without torque of concern (comparatively) there will always be a smooth ride in a jet. I think we can all agree that what makes IL-2 is the challange of flying high performance pistons. Anyone could fly jets in comparison (waits for a barrage of insults).
If memory serves me correct Steinhoff was burned on landing an Me-262. He later became a Luftwaffe General in command and NATO representative after the war.
The P-47 I have in cloudy recall was a specialist aircraft boosted beyond the service P-47.

Buzzsaw-
08-06-2008, 07:37 PM
Originally posted by Kettenhunde:
Buzzsaw,

Do you the nickname JG26 gave the 56th FG P47's?

Nicht-Einmischer.

All the best,

Crumpp

Maybe you can give us a translation. It seems to be a colloquial expression beyond the range of online translators.

I get "Not Backseat drivers"

unless the word is really "Einmischen", in which the case the translation would seem to be:

"Don't interfere"

In any case, considering the 56th F.G.'s 9-1 kill to loss ratio, and highest kill total for any USAAF F.G., (665.5, more than the best P-51 group) no doubt they were regarded as a pretty good opponent.

KrashanTopolova
08-06-2008, 08:14 PM
<span class="ev_code_RED">M-Gunz, here is your vindication of sorts</span>

The following is a transcript of a DVD interview with Lt-Col Francis Gabreski. This seems to be the same interview I once saw on DVD. I appear to have recalled 5 seconds instead of 5 minutes.

In it the late Mr Gabreski gives an example of 3-5 minutes of boost being used in a dogfight to give an advantage.

I say 'of sorts' because a full 3-5 minutes does not have to be fully engaged, 5 seconds 'boost' may also be adequate for a particular technique and that is the point I was making re: PP Vs 'Boost'. Others also have found in game the advantage of co****r PP in gaining acceleration; particularly turning even slightly downhill (see other topics).

Nevertheless, the dogfight recollection article is a good insight into the use of 'boost' when your supercharger is damaged.

This thread, I hope you will agree got down to nuts and bolts of piston CEM.

Best Wishes

http://home.scarlet.be/ed.ragas/awshistory/awsgabreski.html

Buzzsaw-
08-06-2008, 08:35 PM
Salute

Those who commented that the 262's allowable dive limit was higher than the P-47's, or that the P-47 could not maintain this speed are missing the point.

Of course, in most cases a piston engined aircraft could not chase down a Jet moving at full speed, or when that Jet had some room to dive away.

But in fact, Jets, like other aircraft did not cruise at their maximum speeds. And when they were caught at a lower speed, with the disadvantage of enemy aircraft above them, and with little diving room below, then they were in trouble. No matter if the aircraft which shot them down was considerably slower in rated top speed.

The first 262 was shot down on 5 October 1944, by Spitfire IXs of No. 401 RCAF. The 262 pilot was H.C. Butmann of 3./KG51, and he was not landing or taking off. As we all know, the Spit IX was not known for its top speed.

The most successful allied aircraft, based on numbers flying to the number of Jets shot down, was the Tempest, which also had very high max. dive speed, (540 mph IAS under 10,000 ft) as well as an ability to sustain that speed, due to its laminar flow wing aerofoil, for a considerable time.

The P-51 overall had the largest number of Jets claimed, but of course, there were 1200+ P-51's in the air in '45, compared to approx. 125 Tempests.

Allied aircraft got most of their Jet kills at airfields when they were taking off or landing, but as Allied experience was gained versus the Jets, many were also shot down while making attacks on Bomber formations. The technique of the 262's when attacking bombers, was the opposite of the Luftwaffe piston engined fighters, who liked to attack headon. The Jets found the headon meant the closing speeds were so high the amount of time available to aim and shoot was too small. So they made their attacks from behind and below, diving below the altitude of the bombers, and then zooming to make an attack from approx. six o'clock low, and passing through the bomber formation in a zoom.

To counter this, the Allied escorts would take a position far above the bombers, and they would wait for the Jets to start their zoom then dive and catch them when their speed had bled off at the top of their zooms.

Overall the 262's were quite successful, more than fulfilling their design goals. But they were not invulnerable when countered by intelligent tactics on the part of their piston engined opponents.

Guncam from USAAF P-51:

http://www.ww2aircraft.net/forum/attachments/aviation/5642-piston-engine-aircraft-jet-kills-r3-25_598.jpg

luftluuver
08-06-2008, 09:19 PM
Jets cruised at the top speed of piston fighters.

There was several Mk IXs (5) involved in the shooting down of Buttmann. It was the first jet to fall to British Commonwealth Air Forces but not the first jet as the 365th FG claimed one a few days before.

M_Gunz
08-06-2008, 10:47 PM
Originally posted by KrashanTopolova:
<span class="ev_code_RED">M-Gunz, here is your vindication of sorts</span>

The following is a transcript of a DVD interview with Lt-Col Francis Gabreski. This seems to be the same interview I once saw on DVD. I appear to have recalled 5 seconds instead of 5 minutes.

In it the late Mr Gabreski gives an example of 3-5 minutes of boost being used in a dogfight to give an advantage.

I say 'of sorts' because a full 3-5 minutes does not have to be fully engaged, 5 seconds 'boost' may also be adequate for a particular technique and that is the point I was making re: PP Vs 'Boost'. Others also have found in game the advantage of co****r PP in gaining acceleration; particularly turning even slightly downhill (see other topics).

Nevertheless, the dogfight recollection article is a good insight into the use of 'boost' when your supercharger is damaged.

This thread, I hope you will agree got down to nuts and bolts of piston CEM.

Best Wishes

http://home.scarlet.be/ed.ragas/awshistory/awsgabreski.html

It was the statement about 5 seconds WEP as a limit, among other things, that I had problem with.

With CSP you have rpm control also, not direct prop pitch control. Run a 109E with auto-pitch
off and you will have true pitch control. It's possible to do very well that way but there is
more workload, about like running a sports car with stick as opposed to automatic on a rapidly
changing course kind of workload. Increasing speed rapidly without adjusting the pitch by hand
in that mode is a good way to blow the engine, it's very easy to do in seconds during takeoff
if the gear and flaps take too much time and attention for example.

We've just gotten into some of the basics on IL2 CEM as I've know it since way back.
As far as dives and reducing rpm, I've posted on that since the first months that FB was out.
I've even given ways to test and check to see how I got my conclusions. Simply if the engine
does not have the power to maintain the speed of the plane, the prop becomes a drag producer
instead of a thrust producer and drag increases with the square of speed. Not even the weight
of the plane can overcome that at high dive speeds. If we had mach compression in the model
there would be greater separation in the terminal dive speeds across the board though.

Parts of CEM we have only scratched here are radiator use and engine heat. There have been some
very detailed threads on historic data of those for many planes here in the past just as there
have been on the subject of WEP. There's guys here with records I don't keep on all of that,
many of them haven't come here in years though.

EAW was the first combat prop sim I played where engine management figured into engine heat and
that answered for me many whys different WWII fighters with not the highest top speeds were
still very effective. It changed things for me in ways that spec quoting historians did not.
There's more to it than EAW modeled but that one change was a big step from what came before
in combat sims at least that I had or heard of. We have that and more with IL2 yet there are
many IL2 players that still run around cranked out DF-style and don't get it at all.

julian265
08-07-2008, 03:06 AM
haha - he said co****

:P

Kettenhunde
08-07-2008, 04:06 AM
In any case, considering the 56th F.G.'s 9-1 kill to loss ratio, and highest kill total for any USAAF F.G., (665.5, more than the best P-51 group) no doubt they were regarded as a pretty good opponent.

There is doubt the 56th FG amassed a good record. They did this by sticking to Gabreski's orders not to dogfight but use hit and run tactics.

This led to the nickname.

It literally translates to "non-mixer" but would be better translated as "someone who does not interfere" or in the context of the air war, dogfight.

It was a derogatory term in the way JG26 used it, not a compliment or admiration.

All the best,

Crumpp

Bremspropeller
08-07-2008, 05:40 AM
If memory serves me correct Steinhoff was burned on landing an Me-262.

He was taking-off.
His a/c was heavily laden with fuel and rockets.
As he accelerated down the runway, he oversaw a fresh bomb-crater and ran through it, rendering the a/c uncontrollable and crashing shortly after trying to lift-off anyway.

He then was pulled out of the burning jet by some ground-crew.

M_Gunz
08-07-2008, 05:43 AM
Same way onwhiners who don't get e-fighting say "Run-90's" or "Runstangs".

When it's all you can do, it gets down to name calling.

Xiolablu3
08-07-2008, 05:47 AM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> In any case, considering the 56th F.G.'s 9-1 kill to loss ratio, and highest kill total for any USAAF F.G., (665.5, more than the best P-51 group) no doubt they were regarded as a pretty good opponent.

There is doubt the 56th FG amassed a good record. They did this by sticking to Gabreski's orders not to dogfight but use hit and run tactics.

This led to the nickname.

It literally translates to "non-mixer" but would be better translated as "someone who does not interfere" or in the context of the air war, dogfight.

It was a derogatory term in the way JG26 used it, not a compliment or admiration.

All the best,

Crumpp </div></BLOCKQUOTE>

Thats pretty funny when you think about, since Jg26 had been using these tactics vs Spitfires since 1940. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

You hear time after time RAF veterans complaining how usually German fighters would avoid 'mixing it' and go into screaming dives towards france.

It can only be regarded as sensible tactics vs a more manouverable/better turning plane. Whether its the Luftwaffe doing it or the USAAF.

Buzzsaw-
08-08-2008, 07:13 PM
Originally posted by Kettenhunde:

There is doubt the 56th FG amassed a good record. They did this by sticking to Gabreski's orders not to dogfight but use hit and run tactics.

Crumpp

Your facts are completely wrong. You may be an authority on FW190's but you need to do some research before you present information re. the USAAF.

For one, Gabreski was not in charge of the 56th F.G. so he couldn't give 'orders' not to dogfight. He was only a Flight Leader to start with in February '43. His highest rank was as leader of the 61st Fighter Squadron of the Group, but that wasn't till November '43. Policy for Squadrons was according to the Group Commanders dictates, which were in turn driven by the 8th AAF Commanders policies. The Group commander for most of the high scoring period of the 56th F.G.'s record was 'Hub' Zemke, who emphasized aggressive behaviour. When he wasn't in charge, #2 was Dave Schilling. For a brief two month period in Nov. of '43, Zemke was replaced by Robert Landry, who did not fly much. Gabreski then was given temporary command of the 61st Fighter Squadron. In that period Schilling was the primary leader, with Gabreski occasionally filling in. Zemke's policies remained in effect during Zemke's temporary abscence. When Zemke came back in Jan '44, Gabreski was demoted back to Flight Leader, and Zemke was again was the primary leader, with Schilling filling in. In April '44, Gabreski was promoted to command the 61st again, but remained down on the command chain, behind Zemke and Schilling. He was shot down on July 20th '44.

8th AAF policy under General Ira Eaker was for Fighters to stay with the bombers they were escorting. P-47's were not to drop below 15,000 feet. If the enemy dove below 15,000 ft, they would pull up.

In January 1944, under new 8th Commander General James Doolittle, the Fighters, including P-47's were given carte blanche to engage anytime and anywhere. They were told that on their return trips back to their fields, that they should dive down and attack German fighter airfields on their path. With the improved performance the P-47's got from Paddle blade propellors, Water Injection and increased boost levels, and the use of 150 octane fuel, the P-47's were able to operate very successfully even at lower altitudes.

USAAF P-47 pilots were no different from any other fighter pilot. They fought using tactics which were based on the strong points of their assigned aircraft. In the case of the P-47, the strong points were good speed, tremendous dive acceleration, and excellent zoom climbs. Against slower better turning aircraft they used tactics which emphasized those qualities. But they had no problem in attacking aggressively and mixing it up.

For example:

http://www.wwiiaircraftperformance.org/p-47/er/4-anderson-30jan44.jpg

Combat report courtesy of WWII Aircraft Performance:

http://www.wwiiaircraftperformance.org/

M_Gunz
08-08-2008, 11:06 PM
But it's the fun of shootin the bastages thet rilly counts!

Bremspropeller
08-09-2008, 03:14 AM
Your facts are completely wrong. You may be an authority on FW190's but you need to do some research before you present information re. the USAAF.

Can you smell the fire? http://forums.ubi.com/images/smilies/59.gif

Kettenhunde
08-09-2008, 04:57 AM
56th F.G.'s record was 'Hub' Zemke,

I made a mistake and my post should have read:


There is doubt the 56th FG amassed a good record. They did this by sticking to Zemke's orders not to dogfight but use hit and run tactics.

This led to the nickname.

It literally translates to "non-mixer" but would be better translated as "someone who does not interfere" or in the context of the air war, dogfight.

It was a derogatory term in the way JG26 used it, not a compliment or admiration.


Nothing in any of my posts has any bearing whatsoever on individual aircraft performance. You greatly overestimate the impact of any individual aircraft's performance. It's common on these boards as, like you, many tend to think of history in terms of their game. I think more education on the science of aircraft as well as more practical experience would eliminate much of these conversations. I will leave the individual "my plane is best" up to you.

The rest of your post has absolutely no bearing whatsoever on Jagdgeschwader 26's perception of the P47 squadrons in the USAAF.

That perception is entirely their own and based on their own experience.

All the best,

Crumpp

Kettenhunde
08-09-2008, 05:01 AM
Can you smell the fire?

Not really. I won't stoop to that level of immaturity.

Buzzsaw-
08-10-2008, 12:12 AM
Originally posted by Kettenhunde:
I made a mistake and my post should have read:

[QUOTE]There is doubt the 56th FG amassed a good record. They did this by sticking to Zemke's orders not to dogfight but use hit and run tactics.
All the best,

Crumpp

Sorry Crumpp, but you are incorrect again.

At NO time did Zemke order his pilots to avoid dogfights. At NO time did he order them to 'hit and run'.

In fact, Zemke was known as someone who consistently pushed for more aggressive tactics and for his pilots to attack whatever the odds. He was a prime mover in the tactical changes adopted by Gen. Doolittle, ie. to move out from the bombers and engage any and all targets.

He developed the 'Zemke fan', which was the technique of splitting the Fighter Groups into smaller formations and pushing those smaller formations out in front of the bombers in order to breakup and disrupt German attacking formations before they could get close to the bombers. Instead of operating in Squadron formations, he split his Squadrons in half. Those 1/2 Squadrons were told to engage ANY enemy aircraft they sighted, IMMEDIATELY, regardless of the numbers. Since the German Fighter controllers maneuvered their interceptors in Gruppe sized formations, it became common for a 1/2 Squadron of USAAF fighters, (8 planes) to be pitted against 30-50 Germans in the initial phase of combat before the rest of the USAAF F.G. could arrive if they actually did.

Another example of the aggressive style of the 56th F.G. as 4 aircraft attack 9 and stay to mix it up:

http://www.wwiiaircraftperformance.org/p-47/er/56-chattaway-15april44.jpg

Bottom line: The Luftwaffe Jagdflieg lost approx. 40% of its pilot strength EVERY month between February '44 and May of '44. During that period, the P-47 was BY FAR the most numerous fighter in the 8th AAF, and the great majority of the German pilots were shot down by P-47's.

Whatever names JG-26 might want to call them, doesn't alter the fact they were devastating the German Fighter force.

JtD
08-10-2008, 01:21 AM
Originally posted by Buzzsaw-:

Bottom line: The Luftwaffe Jagdflieg lost approx. 40% of its pilot strength EVERY month between February '44 and May of '44. During that period, the P-47 was BY FAR the most numerous fighter in the 8th AAF, and the great majority of the German pilots were shot down by P-47's.

It lost about 20% each month and that is about as much as it lost August-October 1943 but about twice as much as in November 43 - January 44.

They had an aircraft turnover of about 40%, though. In that period the Germans learned the hard way that the twin engined night fighters could no longer be used as day interceptors.

Kettenhunde
08-10-2008, 06:28 AM
At NO time did Zemke order his pilots to avoid dogfights. At NO time did he order them to 'hit and run'.


Buzzsaw,

ONCE again.

JG26's experience is their own. Zemke certainly did tell his guys to avoid mixing it up in early 1943.

You keep referring to later in the war after Doolittle released the USAAF fighters.

General Kepner previously had other ideas about the role of USAAF fighters. Zemke certainly did follow orders with his command.

http://img255.imageshack.us/img255/9034/generalkepnersordersusamw2.jpg (http://imageshack.us)
http://img255.imageshack.us/img255/9034/generalkepnersordersusamw2.dac0687012.jpg (http://g.imageshack.us/g.php?h=255&i=generalkepnersordersusamw2.jpg)

Let's examine the figures from that time period instead of combat reports of one or two dogfights, let's try and get the big picture.

First let's take a look at the relative training and flight experience of the pilots engaged:

In June 1943, the USAAF and German pilots are relatively even in the amount of training each receives. After June 1943, the German pilots are not trained nearly as well as the USAAF pilots.

Pilot training and experience:

http://img180.imageshack.us/img180/1751/flyinghourssl7.jpg (http://imageshack.us)
http://img180.imageshack.us/img180/1751/flyinghourssl7.5b5a384eef.jpg (http://g.imageshack.us/g.php?h=180&i=flyinghourssl7.jpg)

http://img528.imageshack.us/img528/2507/traininghoursej5.jpg (http://imageshack.us)
http://img528.imageshack.us/img528/2507/traininghoursej5.0005eef3e7.jpg (http://g.imageshack.us/g.php?h=528&i=traininghoursej5.jpg)

Now let's examine the size of the forces in the air:

http://img255.imageshack.us/img255/5866/sizeofopposingforcesac1.jpg (http://imageshack.us)
http://img255.imageshack.us/img255/5866/sizeofopposingforcesac1.ba7e146268.jpg (http://g.imageshack.us/g.php?h=255&i=sizeofopposingforcesac1.jpg)

In 1943, the German fighters were on equal footing with the USAAF in terms of numbers, training, and experience.

Now let's compare with the combats in 1944:

The loss rates certainly reflect Doolittle's order to release the USAAF fighters as well. Here we can see that when the USAAF did begin to actively pursue German fighters instead of concentrating on protecting bombers, losses increased on both sides considerably.

The total losses of the USAAF fighters increases ~4.5 times during 1944:

http://img255.imageshack.us/img255/7409/lossratesac4.jpg (http://imageshack.us)
http://img255.imageshack.us/img255/7409/lossratesac4.1b739df55c.jpg (http://g.imageshack.us/g.php?h=255&i=lossratesac4.jpg)

Keep in mind that ~32% loss rate of the Luftwaffe is a smaller actual number than the 22% of the USAAF fighters due to the relative size of the forces.

For example:

250 LW fighters * 32% = 80 LW fighters

900 USAAF Fighter * 22% = 198 USAAF Fighters

These losses are a consequence of dog fighting and the aggressiveness of the USAAF.

Here we can see that losses solely due to tangling with German fighters rises to 8 times the number lost in 1943:

http://img528.imageshack.us/img528/4536/usaaflossesmp7.jpg (http://imageshack.us)
http://img528.imageshack.us/img528/4536/usaaflossesmp7.ab628beda2.jpg (http://g.imageshack.us/g.php?h=528&i=usaaflossesmp7.jpg)

The USAAF records show 161 USAAF fighters lost in air to air combat with German fighters in 1943. The USAAF records show 1293 USAAF fighters lost in air to air combat with German fighters in 1944.

The losses due to combat with German fighters increased 8 times when Doolittle released the USAAF Fighters to tangle with Luftwaffe Fighters.

All the best,

Crumpp

Xiolablu3
08-10-2008, 09:47 AM
I think Crumpp is correct, Buzzsaw, the US pilots learned very early in mock dogfights with Spitfires, and from comments from the Eagle squadron guys that they should avoid 'mixing it' with the enemy in their P47's.

Below is a piece written by a P47 pilot

'One day in January 1943 General Hunter, the Commander of the 8th Fighter Command, came to visit us at Debden. He said he had a 'surprise' for us. We were soon to re-equip with the very latest American fighter, the P-47 Thunderbolt. As he spoke we heard an unusual engine noise outside and one of the new fighters landed and taxied up beside one of our Spitfires. We went outside to look it over. It was huge"”the wing tip of the P-47 came higher than the cockpit of the Spitfire. When we strapped into a Spitfire we felt snug and part of the aircraft"”the Thunderbolt cockpit, on the other hand, was so large that we felt if we slipped off the *******ed seat we would break a leg! We were horrified at the thought of going to war in such a machine: we had enough trouble with the Focke-Wulf 190's in our nimble Spitfire Vs"”now this lumbering seven-ton monster seemed infinitely worse, a true 'air inferiority fighter'. Initial mock dog-fights between Thunderbolts and Spitfires seemed to confirm these feelings"”we lost four Thunderbolt pilots in rapid succession, spinning in from low level, while trying to match Spitfires in turns. In the end our headquarters issued an order banning mock dog fighting in Thunderbolts below 8,000 feet.

Gradually however, we learnt how to fight in the Thunderbolt. At high altitude, she was a 'hot ship' and very fast in the dive; the technique was not to 'mix it' with the enemy, but to pounce on him from above, make one quick pass and get back up to altitude; if anyone tried to escape from a Thunderbolt by diving, we had him cold. Even more important, at last we had a fighter with the range to penetrate deeply into enemy territory"”where the action was. So, reluctantly, we had to give up our beautiful little Spitfires and convert to the new juggernauts. The war was moving on, and we had to move with it.

The change to the Thunderbolt might have been necessary militarily, but my heart remained with the Spitfire. Even now, thirty years after I flew them on operations, the mere sound or sight of a Spitfire brings me a deep feeling of nostalgia, and many pleasant memories. She was such a gentle little airplane, without a trace of viciousness. She was a dream to handle in the air. I feel genuinely sorry for the modern fighter pilot, who has never had the chance to get his hands on a Spitfire"”he will never know what real flying was like.'


http://www.aviation-history.com/republic/p47.html

luftluuver
08-10-2008, 10:11 AM
Originally posted by Kettenhunde:
First let's take a look at the relative training and flight experience of the pilots engaged:

In June 1943, the USAAF and German pilots are relatively even in the amount of training each receives.

Only if one compares German maximum hours and American minimum hours for the Oct. 42 to June 43 time period.

luftluuver
08-10-2008, 10:50 AM
1943

month - on hand - loss to ea - %

Jan - 458 - 3 - 0.66
Feb - 432 - 1 - 0.23
Mar - 358 - 1 - 0.28
Apr - 297 - 5 - 1.68
May - 332 - 9 - 2.71
Jun - 346 - 8 - 2.31
Jul - 426 - 14 - 3.29
Aug - 668 - 7 - 1.05
Sep - 939 - 10 - 1.06
Oct - 1270 - 13 - 1.02
Nov - 1621 - 53 - 3.27
Dec - 1862 - 1.99

1944

month - on hand - loss to ea - %

Jan - 2532 - 57 - 2.25
Feb - 3002 - 69 - 2.30
Mar - 3440 - 54 - 1.57
Apr - 3697 - 201 - 5/44
May - 3570 - 176 - 4.93
Jun - 3219 - 147 - 2.57
Jul - 3671 - 65 - 1.77
Aug - 3725 - 100 - 2.68
Sep - 3759 - 104 - 2.77
Oct - 4040 - 99 - 2.45
Nov - 4204 - 80 - 1.90
Dec - 4002 - 141 - 3.52

Kettenhunde
08-10-2008, 11:23 AM
Only if one compares German maximum hours and American minimum hours for the Oct. 42 to June 43 time period.


Certainly.

Interesting to compare those monthly percentages with the size of the relative forces.

All the best,

Crumpp

Buzzsaw-
08-10-2008, 05:36 PM
Originally posted by Xiolablu3:
I think Crumpp is correct, Buzzsaw, the US pilots learned very early in mock dogfights with Spitfires, and from comments from the Eagle squadron guys that they should avoid 'mixing it' with the enemy in their P47's.

Below is a piece written by a P47 pilot

'One day in January 1943 General Hunter, the Commander of the 8th Fighter Command, came to visit us at Debden. He said he had a 'surprise' for us. We were soon to re-equip with the very latest American fighter, the P-47 Thunderbolt. As he spoke we heard an unusual engine noise outside and one of the new fighters landed and taxied up beside one of our Spitfires. We went outside to look it over. It was huge"”the wing tip of the P-47 came higher than the cockpit of the Spitfire. When we strapped into a Spitfire we felt snug and part of the aircraft"”the Thunderbolt cockpit, on the other hand, was so large that we felt if we slipped off the *******ed seat we would break a leg! We were horrified at the thought of going to war in such a machine: we had enough trouble with the Focke-Wulf 190's in our nimble Spitfire Vs"”now this lumbering seven-ton monster seemed infinitely worse, a true 'air inferiority fighter'. Initial mock dog-fights between Thunderbolts and Spitfires seemed to confirm these feelings"”we lost four Thunderbolt pilots in rapid succession, spinning in from low level, while trying to match Spitfires in turns. In the end our headquarters issued an order banning mock dog fighting in Thunderbolts below 8,000 feet.

Gradually however, we learnt how to fight in the Thunderbolt. At high altitude, she was a 'hot ship' and very fast in the dive; the technique was not to 'mix it' with the enemy, but to pounce on him from above, make one quick pass and get back up to altitude; if anyone tried to escape from a Thunderbolt by diving, we had him cold. Even more important, at last we had a fighter with the range to penetrate deeply into enemy territory"”where the action was. So, reluctantly, we had to give up our beautiful little Spitfires and convert to the new juggernauts. The war was moving on, and we had to move with it.

The change to the Thunderbolt might have been necessary militarily, but my heart remained with the Spitfire. Even now, thirty years after I flew them on operations, the mere sound or sight of a Spitfire brings me a deep feeling of nostalgia, and many pleasant memories. She was such a gentle little airplane, without a trace of viciousness. She was a dream to handle in the air. I feel genuinely sorry for the modern fighter pilot, who has never had the chance to get his hands on a Spitfire"”he will never know what real flying was like.'


http://www.aviation-history.com/republic/p47.html

This is a piece from a former 'Eagle Squadron' member, who was converted to 4th F.G. when the U.S. entered the war, then flew Spitfires. Some of these guys never understood how to fly a Thunderbolt.

If I was at home, (I am on a business trip for a month) I could quote from my copy of 'Thunderbolt', by Robert Johnson, where he details how he outmaneuvered a Spitfire while flying a Thunderbolt, by using his superior rollrate at speed and the dive acceleration and zoom climb. 56th Fighter Group started with Thunderbolts and remained with them for the entire war. They knew their aircraft extremely well.

Bremspropeller
08-10-2008, 05:42 PM
If I was at home, (I am on a business trip for a month) I could quote from my copy of 'Thunderbolt', by Robert Johnson, where he details how he outmaneuvered a Spitfire while flying a Thunderbolt, by using his superior rollrate at speed and the dive acceleration and zoom climb.

I'd take Johnson's accounts with two grains of salt, as he likes to shed everything in a more dramatic way than it propably was.

KrashanTopolova
08-10-2008, 06:38 PM
Originally posted by Buzzsaw-:
USAAF P-47 pilots were no different from any other fighter pilot. They fought using tactics which were based on the strong points of their assigned aircraft. In the case of the P-47, the strong points were good speed, tremendous dive acceleration, and excellent zoom climbs. Against slower better turning aircraft they used tactics which emphasized those qualities. But they had no problem in attacking aggressively and mixing it up.


You forgot the 8x0.5s...(top of list ?)

M_Gunz
08-10-2008, 07:20 PM
Originally posted by Bremspropeller:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If I was at home, (I am on a business trip for a month) I could quote from my copy of 'Thunderbolt', by Robert Johnson, where he details how he outmaneuvered a Spitfire while flying a Thunderbolt, by using his superior rollrate at speed and the dive acceleration and zoom climb.

I'd take Johnson's accounts with two grains of salt, as he likes to shed everything in a more dramatic way than it propably was. </div></BLOCKQUOTE>

There was nothing wrong there, was there? Split-S'd at a point where the Spit pilot couldn't
see him let alone follow. How long for the Spit pilot to see or realize, find and attempt to
follow did he have to start his dive? The hardest part is the particulars left out of the story.
He set up a situation in differences in speeds making differences in timing with his plane's
best traits being the ones used. When you set your opponent so many seconds back then you get
a tactical advantage of those seconds in distance you can use at whatever speed you can manage
which is where fast is best.
You have to remember that in lower speed maneuvers like sustained climb and flat turn, he
would lose time/distance. But it's the tactics and the response that count.

WTE_Galway
08-10-2008, 07:26 PM
Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Buzzsaw-:
USAAF P-47 pilots were no different from any other fighter pilot. They fought using tactics which were based on the strong points of their assigned aircraft. In the case of the P-47, the strong points were good speed, tremendous dive acceleration, and excellent zoom climbs. Against slower better turning aircraft they used tactics which emphasized those qualities. But they had no problem in attacking aggressively and mixing it up.


You forgot the 8x0.5s...(top of list ?) </div></BLOCKQUOTE>

The fact they needed to fit 8 of the things says something about the 0.50 cal browning by the mid 1940's.

Buzzsaw-
08-10-2008, 11:15 PM
Originally posted by Kettenhunde:

JG26's experience is their own. Zemke certainly did tell his guys to avoid mixing it up in early 1943.



Provide a direct quote from Zemke to that effect. I'd like to see it. I doubt I will. I have read Zemke's autobiography and many accounts of the campaign. All the facts I have seen prove the opposite.


Originally posted by Kettenhunde:

General Kepner previously had other ideas about the role of USAAF fighters. Zemke certainly did follow orders with his command.

http://img255.imageshack.us/img255/9034/generalkepnersordersusamw2.jpg (http://imageshack.us)
http://img255.imageshack.us/img255/9034/generalkepnersordersusamw2.dac0687012.jpg (http://g.imageshack.us/g.php?h=255&i=generalkepnersordersusamw2.jpg)



This document does not prove your argument, only confirms what I have already posted earlier in this thread, which is that Kepner, who was acting under orders from Gen. Ira Eaker, told his F.G. Commanders that they were not to leave the bombers, and not to drop below 15,000 ft. It says ZERO about dogfighting and mixing it up. If there were enemy fighters near the bombers, the USAAF fighters were expected to attack and mix it up with the enemy till there was no longer a threat to the bombers.


Originally posted by Kettenhunde:

Let's examine the figures from that time period instead of combat reports of one or two dogfights, let's try and get the big picture.

First let's take a look at the relative training and flight experience of the pilots engaged:

In June 1943, the USAAF and German pilots are relatively even in the amount of training each receives. After June 1943, the German pilots are not trained nearly as well as the USAAF pilots.



Sounds to me like you are trying to make excuses for the Luftwaffe performance. It was their fault they did not delegate enough experienced pilots to the training schools. Instead they kept their Aces flying to build up their victory totals, when they should have been back in Germany imparting their experience to the 'nachwuchs'.


Originally posted by Kettenhunde:

Now let's examine the size of the forces in the air:

http://img255.imageshack.us/img255/5866/sizeofopposingforcesac1.jpg (http://imageshack.us)
http://img255.imageshack.us/img255/5866/sizeofopposingforcesac1.ba7e146268.jpg (http://g.imageshack.us/g.php?h=255&i=sizeofopposingforcesac1.jpg)

In 1943, the German fighters were on equal footing with the USAAF in terms of numbers, training, and experience.



First of all, your facts are wrong, the Germans had larger numbers of Fighters through the first half of '43, by the end of '43, the USAAF had larger numbers. Second, numbers are not a good indicator of the requirements. The Luftwaffe had more fighters in the air in the BoB too, many of them never saw a Spitfire or Hurricane during their escorts, and the distance they had to escort was a tiny fraction of the distances the USAAF had to fly.

The USAAF fighters could not remain with the bombers the whole trip, not even P-51's could do that. The cruise speeds of the Fighters and the bombers were not the same, the Fighters had to weave back and forth, covering a larger distance, thus running out of fuel sooner. To cover a single Bomber 'Box' (approx. 60 B-17's or B-24's) on its way to a target in Germany, required a minimum of four different escort forces assigned to it. Initially, the bombers were escorted by Squadrons of RAF Spitfires or Mustangs to the European Coast. Then the first leg of the trip, the trip to the target, required a USAAF Fighter Group as escort force. At the target, that force broke off and was relieved by a second USAAF Fighter Group which escorted from the target back to the coast. Finally, at the European Coast, the Bombers would once again be picked up by RAF fighters. If the target was in Eastern Germany or Czecheslovakia, up to six different escort Groups could be required.

Each Bomber box required a separate set of escorts, since the boxes were strung out in a long line, sometimes up to 100 kilometers in length. A Fighter Group could not cover the whole stream but had to focus on their assigned Bomber box.

The Germans would not intercept all of the bomber boxes in an attack force, they would focus their strength on a particular section of it, so many of the escorts would not see combat, since their box was not attacked. Meanwhile another section of the bomber stream would be under nearly continuous attack.


Originally posted by Kettenhunde:

Now let's compare with the combats in 1944:

The loss rates certainly reflect Doolittle's order to release the USAAF fighters as well. Here we can see that when the USAAF did begin to actively pursue German fighters instead of concentrating on protecting bombers, losses increased on both sides considerably.

The total losses of the USAAF fighters increases ~4.5 times during 1944:

http://img255.imageshack.us/img255/7409/lossratesac4.jpg (http://imageshack.us)
http://img255.imageshack.us/img255/7409/lossratesac4.1b739df55c.jpg (http://g.imageshack.us/g.php?h=255&i=lossratesac4.jpg)

Keep in mind that ~32% loss rate of the Luftwaffe is a smaller actual number than the 22% of the USAAF fighters due to the relative size of the forces.

For example:

250 LW fighters * 32% = 80 LW fighters

900 USAAF Fighter * 22% = 198 USAAF Fighters



You quote figures which are not those shown by your own tables... http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Where do you get this figure of 32%? The loss rates for the Western front for the German fighters shown by your table are 47% for 1943 and 92% for 1944.

Second, where do you get the figure of 250 for the German fighter total? http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif There were over 1500 German operational fighters on the Western front in Jan. of 1944. That does not include Fighters which were in repair status at their airfield, or on the way from depot to the Squadrons. It does not include the Mediterranean front.

And the 22% loss rate number for the USAAF is ALL losses, includes Fighters lost due to flak, the #1 reason for Fighter losses for the Allied side.


Originally posted by Kettenhunde:

These losses are a consequence of dog fighting and the aggressiveness of the USAAF.



Not correct, most losses suffered by USAAF Fighters were from those in the ground attack F.G.'s as is shown clearly by your own tables. 2449 USAAF Fighters lost to AAA, compared to 1691 lost to air to air.

Whether you want to admit it or not, the Fighter Arm of the Luftwaffe was decimated by the USAAF in the spring of '44, an event from which it never recovered qualitatively. Goering was able to maintain large numbers of aircraft in the air, but they were piloted overwhelmingly by rookies. That period of 5 months, from Jan. '44 to May '44 was a period when the P-47 and the 56th Fighter Group excelled, and where they gained the majority of their 665.5 victory claims. No doubt that some of that total are overclaims, (postwar research shows that the RAF, Luftwaffe and USAAF all overclaimed, on average at a rate of 1.5 to 1) but their victories, compared to the 74 losses they suffered in air to air, look pretty good and speak well of the ability of the P-47 and its pilots.

Kettenhunde
08-11-2008, 04:17 AM
I think you are having some trouble reading and comprehending, buzzsaw.


Provide a direct quote from Zemke to that effect. I'd like to see it. I doubt I will. I have read Zemke's autobiography and many accounts of the campaign. All the facts I have seen prove the opposite.


JG26's experience is their own. I don't know how to explain it better than that. The USAAF does not own the German pilots perceptions.


First of all, your facts are wrong, the Germans had larger numbers of Fighters through the first half of '43, by the end of '43, the USAAF had larger numbers.

The graph is number of aircraft present on missions and not total numbers of aircraft.


Where do you get this figure of 32%? The loss rates for the Western front for the German fighters shown by your table are 47% for 1943 and 92% for 1944.



I got that figure because I read the graph. The graph shows total loss rates for the Luftwaffe and includes the Eastern Front. If you subtract the Eastern Front loss rate from the total, you will arrive at the loss rate for the Western Front and MTO.


Second, where do you get the figure of 250 for the German fighter total?

By reading the graph once again, there were several points where the Luftwaffe had ~250 fighters to respond.

This is a complete sidetrack of the topic however as my figures only serve to demonstrate one must consider the relative size of the forces when looking at percentage losses.


Not correct, most losses suffered by USAAF Fighters were from those in the ground attack F.G.'s as is shown clearly by your own tables. 2449 USAAF Fighters lost to AAA, compared to 1691 lost to air to air.


The losses to AAA and other causes are not considered, buzzsaw.

Only the Air to Air losses which increased 8 times the number lost to German fighters in 1943. The USAAF loss sheet breaks it down very clearly with no room to intelligently dispute that fact.


Whether you want to admit it or not, the Fighter Arm of the Luftwaffe was decimated by the USAAF in the spring of '44, an event from which it never recovered qualitatively.

I don't see anywhere that is under dispute except in your own mind.

What is evident is that it was a very hard fought battle of attrition. The veterans who fought it deserve the thanks of a free society.

It is equally evident that the performance of the P47 had little to do with outcome. It certainly was not some gamer fantasy of their favorite game shape flying circles around the opposition.

All the best,


Crumpp

Xiolablu3
08-11-2008, 06:20 AM
Originally posted by Buzzsaw-:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Xiolablu3:
I think Crumpp is correct, Buzzsaw, the US pilots learned very early in mock dogfights with Spitfires, and from comments from the Eagle squadron guys that they should avoid 'mixing it' with the enemy in their P47's.

Below is a piece written by a P47 pilot

'One day in January 1943 General Hunter, the Commander of the 8th Fighter Command, came to visit us at Debden. He said he had a 'surprise' for us. We were soon to re-equip with the very latest American fighter, the P-47 Thunderbolt. As he spoke we heard an unusual engine noise outside and one of the new fighters landed and taxied up beside one of our Spitfires. We went outside to look it over. It was huge"”the wing tip of the P-47 came higher than the cockpit of the Spitfire. When we strapped into a Spitfire we felt snug and part of the aircraft"”the Thunderbolt cockpit, on the other hand, was so large that we felt if we slipped off the *******ed seat we would break a leg! We were horrified at the thought of going to war in such a machine: we had enough trouble with the Focke-Wulf 190's in our nimble Spitfire Vs"”now this lumbering seven-ton monster seemed infinitely worse, a true 'air inferiority fighter'. Initial mock dog-fights between Thunderbolts and Spitfires seemed to confirm these feelings"”we lost four Thunderbolt pilots in rapid succession, spinning in from low level, while trying to match Spitfires in turns. In the end our headquarters issued an order banning mock dog fighting in Thunderbolts below 8,000 feet.

Gradually however, we learnt how to fight in the Thunderbolt. At high altitude, she was a 'hot ship' and very fast in the dive; the technique was not to 'mix it' with the enemy, but to pounce on him from above, make one quick pass and get back up to altitude; if anyone tried to escape from a Thunderbolt by diving, we had him cold. Even more important, at last we had a fighter with the range to penetrate deeply into enemy territory"”where the action was. So, reluctantly, we had to give up our beautiful little Spitfires and convert to the new juggernauts. The war was moving on, and we had to move with it.

The change to the Thunderbolt might have been necessary militarily, but my heart remained with the Spitfire. Even now, thirty years after I flew them on operations, the mere sound or sight of a Spitfire brings me a deep feeling of nostalgia, and many pleasant memories. She was such a gentle little airplane, without a trace of viciousness. She was a dream to handle in the air. I feel genuinely sorry for the modern fighter pilot, who has never had the chance to get his hands on a Spitfire"”he will never know what real flying was like.'


http://www.aviation-history.com/republic/p47.html

This is a piece from a former 'Eagle Squadron' member, who was converted to 4th F.G. when the U.S. entered the war, then flew Spitfires. Some of these guys never understood how to fly a Thunderbolt.

If I was at home, (I am on a business trip for a month) I could quote from my copy of 'Thunderbolt', by Robert Johnson, where he details how he outmaneuvered a Spitfire while flying a Thunderbolt, by using his superior rollrate at speed and the dive acceleration and zoom climb. 56th Fighter Group started with Thunderbolts and remained with them for the entire war. They knew their aircraft extremely well. </div></BLOCKQUOTE>

I have heard/read this many times.

Noone knows who the SPitfire pilot was, maybe a guy on his first ever solo? Maybe a WAAF ferry pilot? Just how good a pilot was this guy/girl?

Probably this person had no idea 'How to fly a Spitfire' and a good pilot would have run rings around Johnson http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Its all about the quality of the pilot. If an RAF Ace had come across an average USAAF fighter pilot then the result would have been obvious.

No doubt if Johnson was in the SPitfire he would also have won. Probably a better pilot in the SPitfire would have seen the manouvre he was about to pull and avoided it.

Too many ifs, and its just one freak incident with no comment from the other pilot.

julian265
08-11-2008, 06:44 AM
Originally posted by Xiolablu3:
Too many ifs, and its just one freak incident with no comment from the other pilot.
So you're asking for a .ntrk? http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Buzzsaw-
08-11-2008, 03:33 PM
Originally posted by Kettenhunde:
I think you are having some trouble reading and comprehending, buzzsaw.



No, I'm having no trouble at all... But it seems you are having a problem admitting a mistake http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

You made a couple of claims: #1 that Gabreski told his pilots not to dogfight or mix it up, #2, that Zemke told his pilots not to dogfight or mix it up. You have provided zero proof of your assertions, which are in fact contradicted by all the statements made by both of these guys.


Originally posted by Kettenhunde:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Where do you get this figure of 32%? The loss rates for the Western front for the German fighters shown by your table are 47% for 1943 and 92% for 1944.



I got that figure because I read the graph. The graph shows total loss rates for the Luftwaffe and includes the Eastern Front. If you subtract the Eastern Front loss rate from the total, you will arrive at the loss rate for the Western Front and MTO.

</div></BLOCKQUOTE>

You are reading the graph incorrectly.

http://img255.imageshack.us/img255/7409/lossratesac4.jpg

The graph indicates average monthly loss rates based on monthly operational numbers available. This breaks down into three elements: 1) Total percentage loss rates based on the total operational fighters available on BOTH the East and West fronts, (this is the bar graph) 2) Percentage Loss rate of the total operationally available for the Eastern Front, (the lower curve graph) 3) Percentage Loss rate of the total operationally available for the Western Front, (the upper curve graph) Since the number of operational aircraft available on the Eastern and Western Fronts were very different totals. For example, in Jan. 44, there were 1500 + operational Fighters available on the Western Front, and only 450 available on the Eastern Front. Therefore the percentage losses for each front contributes different numbers to the total loss percentage. You cannot simply subtract the East front percentage loss number from the total percentage loss number on the bar graph, since 42% of approx. 450 fighters is only 189 aircraft, whereas 92% of 1500+ aircraft is 1380 aircraft. The percentage the Western and Eastern fronts contribute to the total 72% loss rate, (based on the operationally available in Jan. '44 example I provided) are actually approx. 88% for the Western and approx. 12% for the Eastern front.


Originally posted by Kettenhunde:

[QUOTE] Second, where do you get the figure of 250 for the German fighter total?

By reading the graph once again, there were several points where the Luftwaffe had ~250 fighters to respond.




Wrong again. The figures shown are the numbers of German aircraft which were able to intercept, not the total numbers of German aircraft which were available on the front. Only a percentage of the total German fighter strength would be based close enough to a target to make an interception. The USAAF would strike targets all over Germany and Western Czecheslovakia, and the Luftwaffe had to distribute its strength to cover those targets.

[QUOTE]Originally posted by Kettenhunde:




Not correct, most losses suffered by USAAF Fighters were from those in the ground attack F.G.'s as is shown clearly by your own tables. 2449 USAAF Fighters lost to AAA, compared to 1691 lost to air to air.

[QUOTE]

The losses to AAA and other causes are not considered, buzzsaw.

[QUOTE]

Wrong again. You provided a figure of 22%. That comes once again from this chart:

http://img255.imageshack.us/img255/7409/lossratesac4.jpg

Nowhere on this chart does it say these are air to air losses. It in fact says: 'Average Monthly loss of A/C as a Percentage of Effective Strength'. Nothing about air to air.


You are correct in suggesting that the fight was a very hard one, with attrition on both sides, but that attrition and the losses insofar as Fighters are concerned, were very much in favour of the USAAF. Now if you wanted to argue re. the bomber losses, and add them into the percentages, you'd have a better leg to stand on. The Jagdflieg did a admirable job of trying to knock down bombers, (their primary task) and although they fell short, they should be commended. Undoubtably they would have succeeded but for the presence of the USAAF fighters, who inflicted such heavy losses as to doom the Jagdflieg's efforts to failure.

Kettenhunde
08-11-2008, 03:50 PM
Noone knows who the SPitfire pilot was, maybe a guy on his first ever solo? Maybe a WAAF ferry pilot? Just how good a pilot was this guy/girl?


Also we don't know the altitude. Keep in mind that at B17 raid height, the P47 was one of the best performing fighters of the war.

Although I have not done the math, at altitude the P47 could most likely pull a higher sustained load factor at velocity than most WWII fighters.

Here is a graph that one of our members, Faustnik, compiled based off the referenced data. It agrees very will with the USAAF conclusions.

http://img169.imageshack.us/img169/732/1943speedcompareiizr6.gif (http://imageshack.us)
http://img169.imageshack.us/img169/732/1943speedcompareiizr6.4419de5582.jpg (http://g.imageshack.us/g.php?h=169&i=1943speedcompareiizr6.gif)


http://img360.imageshack.us/img360/944/clipboard02za3.jpg (http://imageshack.us)
http://img360.imageshack.us/img360/944/clipboard02za3.7284aebe5c.jpg (http://g.imageshack.us/g.php?h=360&i=clipboard02za3.jpg)

http://img360.imageshack.us/img360/6851/clipboard01iu2.jpg (http://imageshack.us)
http://img360.imageshack.us/img360/6851/clipboard01iu2.f5026efe44.jpg (http://g.imageshack.us/g.php?h=360&i=clipboard01iu2.jpg)

All the best,

Crumpp

Bremspropeller
08-11-2008, 03:51 PM
Kuna's sig, quick!

Kettenhunde
08-11-2008, 06:45 PM
The percentage the Western and Eastern fronts contribute to the total 72% loss rate, (based on the operationally available in Jan. '44 example I provided) are actually approx. 88% for the Western and approx. 12% for the Eastern front.

I think you are right but that print is so small I can't be sure.

Keep in mind the graph shows German losses are to all causes both combat and non-combat. That percentage is not just Allied fighters.

However none of this changes the ultimate conclusion.

Facts are the GAF just had a hard time flying by 1944 not just fighting.

Here are the GAF combat and non-combat losses

http://img360.imageshack.us/img360/4664/germanaircraftlossesinwaw4.gif (http://imageshack.us)
http://img360.imageshack.us/img360/4664/germanaircraftlossesinwaw4.b15f95a4c9.jpg (http://g.imageshack.us/g.php?h=360&i=germanaircraftlossesinwaw4.gif)

If we take the 1944 combat to non-combat loss percentages as a base line, we can get a pretty decent idea of the ratio of attrition due to combat in 1944. Unfortunately we have no way of separating losses to Allied fighters from other causes. We could also multiply the loss numbers by the 88% loss rate on the Western Front. This will not affect the outcome but simply shift the numbers resulting in the same estimated percentage with the lower Western Front numbers.

6259 GAF fighters lost in combat + 3808 GAF fighters lost in non-combat = 10067 aircraft lost to all causes

6259 / 10067 * 100 = 62% of GAF losses to combat related causes.

Looking at the size of the relative forces we see the GAF goes from ~150 Fighters to a high of 300 Fighters. We don't know how many are SE or TE.

~150 fighters * .62 = 93 GAF fighters lost to all combat causes

~300 GAF fighters * .62 = 186 GAF fighters lost to all combat causes

We can quickly estimate that the Germans lost an average of 140 Fighters a month to all combat causes.

The USAAF is much easier to nail down as we have good data for their losses to German Fighters.

http://img360.imageshack.us/img360/4650/usaaflossesun8.jpg (http://imageshack.us)
http://img360.imageshack.us/img360/4650/usaaflossesun8.dea6681454.jpg (http://g.imageshack.us/g.php?h=360&i=usaaflossesun8.jpg)


Here we can see the USAAF lost 1293 Fighters to Air to Air combat in 1944. This brings the average monthly loss rate to 108 fighters a month.

The USAAF averaged 108 fighters a month to GAF Fighters while the GAF lost 140 Fighters to All Combat Causes.

I think it pretty safe to conclude that some of those losses can be attributed to AAA and bombers.

The exchange looks pretty close to 1:1 to me for GAF fighters to USAAF fighters. I would have to conclude that the Luftwaffe gave as good as it got when one factors in the relative size of the forces.

Frankly I find that astounding given the level of superiority of the Allied Pilots but it certainly makes sense given the fact the number of USAAF destroyed by German fighters increased 8 times over the 1943 rates.


attrition and the losses insofar as Fighters are concerned, were very much in favour of the USAAF.

I don't see how anyone can draw this conclusion given the facts especially when one considers the relative size of the forces and clearly superior training of the Allied pilots.

I would think the losses for the GAF would be much higher. Don't you agree?


Wrong again. The figures shown are the numbers of German aircraft which were able to intercept, not the total numbers of German aircraft which were available on the front.

I know that Buzz. We are talking about the relative strengths.

Just how big do you think the German Air Force was BTW?

The GAF had less than 2000 fighters to cover 3 fronts.

To get an idea of the strength of the Luftwaffe:

http://img360.imageshack.us/img360/548/luftwaffestrength2uc2.jpg (http://imageshack.us)
http://img360.imageshack.us/img360/548/luftwaffestrength2uc2.2e06241575.jpg (http://g.imageshack.us/g.php?h=360&i=luftwaffestrength2uc2.jpg)

It would be nice Buzzsaw if you attempted to discuss this in a mature and non-emotional manner. If you are not capable of that you will be ignored.

Don't confuse a lack of response with being correct.

All the best,

Crumpp

R_Target
08-11-2008, 07:35 PM
Originally posted by Bremspropeller:
I'd take Johnson's accounts with two grains of salt, as he likes to shed everything in a more dramatic way than it propably was.

The blame probably lies more with ghostwriter/embellisher Martin Caidin than Johnson himself. That goes double for Caidin's mendacious mangling of Saburo Sakai's story.

Buzzsaw-
08-12-2008, 12:49 AM
Salute KettenHunde/Crumpp

You keep posting all these excellent charts, but unfortunately, they do nothing to support your arguments, rather they undermine them. By the way, are these charts from Williamson Murray's 'Strategy for Defeat, The Luftwaffe 1933 - 1945'? They look familiar.

Anyway, lets try to do this rationally, using the charts you have provided.

Please take the time to look at them carefully.

To begin with your table showing losses for German Fighters


Originally posted by Kettenhunde:

Here are the GAF combat and non-combat losses

http://img360.imageshack.us/img360/4664/germanaircraftlossesinwaw4.gif (http://imageshack.us)
http://img360.imageshack.us/img360/4664/germanaircraftlossesinwaw4.b15f95a4c9.jpg (http://g.imageshack.us/g.php?h=360&i=germanaircraftlossesinwaw4.gif)

If we take the 1944 combat to non-combat loss percentages as a base line, we can get a pretty decent idea of the ratio of attrition due to combat in 1944.



Actually we get a pretty good idea of the ratio of attrition due to combat IN THE FIRST SIX MONTHS OF 1944. Take a look at the top of the chart. Each column is for a six month period. Not for the whole year of 1944.

You then present a whole series of calculations, during which you include the number of aircraft which on average managed to intercept, which you then use to get a percentage number. Without criticising in detail your method of calculation, lets consider your conclusion.


Originally posted by Kettenhunde:

We can quickly estimate that the Germans lost an average of 140 Fighters a month to all combat causes.



Ok, you suggest 140 aircraft lost a month by the Germans on the Western front. In the six month period covered by the chart, using your calculations for average monthly losses, that would mean only 840 Fighter aircraft were lost by the Luftwaffe on the Western Front. Not a very substantial loss, and one which would seem to be contradicted by every history written on the subject.

Back to the chart above.

As you mention, it tells us that in the first six months of 1944, Jan.- June, the Luftwaffe admitted losses of 6259 Fighters to combat causes. We have to assume that figure is for all fronts. Divide that figure by six, gives us an average of 1043 Fighter aircraft lost EVERY month. As previously established, using your calculations, which would have the Luftwaffe only losing 840 Fighters on the Western Front in the ENTIRE six month period covered for the chart, that would mean, by doing a simple subtraction of 840 from the total of 6259, leaves us a figure of 5419 Fighters in additional losses, which must, by your calculation, be sustained on the Eastern front. A bit of an incredible claim, since only 450 Luftwaffe fighters were based on the Eastern Front in Jan. of '44. Using your calculations, the Jagdgeschwader on the Eastern Front, with their 450 aircraft, must have sustained a loss rate of 645% in order to sustain those 5419 Fighters lost. Each Geschwader would have had to lose nearly 6 and 1/2 times its full complement of aircraft every month in order to make your math work with the actual historical totals of German Fighters lost in the first six months of 1944.

A bit of a stretch?

Fortunately we have your earlier posted chart, showing the actual historical percentage loss rates for Luftwaffe Fighters, which clearly shows the loss rate for Luftwaffe Fighters was much higher on the Western front than the Eastern, and in fact details that the loss rate for Fighters on the Eastern front in '44 was actually only 47%, not 645%. That would be this chart:

http://img255.imageshack.us/img255/7409/lossratesac4.jpg

Please take the time to look at it again carefully. Note the 92% loss rate for Fighter aircraft on the Western front in 1944.

Now lets go to the USAAF chart:


Originally posted by Kettenhunde:

http://img360.imageshack.us/img360/4650/usaaflossesun8.jpg (http://imageshack.us)
http://img360.imageshack.us/img360/4650/usaaflossesun8.dea6681454.jpg (http://g.imageshack.us/g.php?h=360&i=usaaflossesun8.jpg)

Here we can see the USAAF lost 1293 Fighters to Air to Air combat in 1944. This brings the average monthly loss rate to 108 fighters a month.



Here we agree. You are right, 108 fighters USAAF Fighters lost a month on the Western front. (average based on the whole year) Compared to an average of 1043 Fighters a month lost for the Luftwaffe on all fronts. (average based on the first six months of '44 and for both fronts) On average, nearly 10 times the numbers of Luftwaffe Fighters lost on all fronts, compared to USAAF Fighters lost on the Western front.

But of course, we need to determine how many of those Luftwaffe Fighters were lost on the Eastern Front versus the Western Front to get a really good ratio of German fighter losses to USAAF.

We can make a pretty close calculation using your charts and the historical figures I have calculated for the number of aircraft based on each of the fronts. You can by the way, do those same calculations I did, by looking at the following German site, (which is based on original documents), going through the Geschwader, locating where they were based at a particular point in time, and then totalling the number of aircraft available to each Gruppe. Takes some time, but can be instructive. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

http://www.ww2.dk/

Basing locations can be found under 'Air units/Fighter units', and the aircraft available numbers can be found under Orders of Battle/Flugzeugbestände und Bewegungsmeldungen, 3.42 - 12.44.

As I asserted earlier, (based on the above site) the Luftwaffe had approx. 450 fighters based on the Eastern front in Jan. '44. They had approx. 1150 fighters based on the Western front at the same time. (I earlier quoted a figure of 1500, I was mistaken, as I said, I am on a business trip don't have access to my computer, and had to recalculate using the above "Luftwaffe" site) Total available for both fronts for Jan. '44 was approx. 1600, which actually agrees with the Jan. '44 figures for Fighters available shown on your third chart, which is here:

http://img360.imageshack.us/img360/548/luftwaffestrength2uc2.jpg

Divide the number of 1600 by the 72% average loss rate for both fronts shown by your third chart, and we get 1152 fighter aircraft lost, which is actually pretty close to the average loss figure for the six month period of 1043 aircraft shown in your first chart. Remembering too, that the 72% figure includes non-combat losses.

Now lets narrow it down to the individual fronts. Loss rate for the Eastern Front based on your second chart shown above was an average of 47% monthly for 1944. Loss rates for the Western front, again as shown by the same second chart, was an average of 92% monthly for '44. Note again that these percentage figures are not just combat losses.

Using the figure of 450 aircraft, (the number of Fighters based on the Eastern front in Jan. '44) divided by a 47% loss rate, we get 211 aircraft lost on the Eastern Front for January. Using the figure of 1150 aircraft, (the number of fighters based on the Western Front in Jan. '44) divided by a 92% loss rate, we get 1058 aircraft lost in January on the Western front. Total the two and we get a figure of 1269 aircraft lost on both fronts. Which is again higher than the listed 1043 monthly average, but since the figure of 1043 is an average of COMBAT losses, and we have calculated all types of losses, our figure should be higher. Plus of course, some months may see more losses, some less. But in any case, the losses for the Luftwaffe Fighter fleet on the Western front are FAR higher, in fact nearly 10 times higher than the 108 aircraft lost on average by the USAAF.

Which goes a long way to proving, that your assertion that the numbers of USAAF fighters lost, and the number of Luftwaffe fighters lost are a relatively similar total is really not sustainable.

The loss figures for Luftwaffe fighters I have quoted also don't include the so-called 'non combat' losses admitted by the Luftwaffe. 3808 aircraft lost, more than 50% of the total of the combat losses. Ie. for every two aircraft lost in combat, 1 is being lost to pilot error, or mechanical failure or whatever... Looking at this number, one might think the Luftwaffe had a very poor set of pilots who had real trouble with their landings... or that the 109 really did swerve as badly as some said on landing... or that the German aircraft factories REALLY had a problem with quality control... http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

But in fact there is a simpler explanation. The Luftwaffe had a fairly unique loss management system, (some would say self-serving system, which disguised real losses) which applied a percentage loss figure to any aircraft which was damaged. For example, an aircraft might be classified as 50% damaged, without being listed as lost to enemy action. This despite the fact the damage was caused by enemy bullets. These types of damaged aircraft were often put aside, cannibalized for parts, and then when there was nothing but the skeleton, written off completely. But when they were written off, the aircraft would not be counted as 'lost to enemy action'.

Of course, many of these aircraft losses were due to enemy action, and should be included in the totals. Which would raise the German loss levels even higher.

With all due respect Crumpp, the key figures to be considered are the losses for each side. Ie. the 6259 figure for the Germans for a six month period, as compared to a 1293 figure for the USAAF for a 1 year period. It's pretty obvious one side is doing better than the other.

Kettenhunde
08-12-2008, 05:05 AM
The loss figures for Luftwaffe fighters I have quoted also don't include the so-called 'non combat' losses admitted by the Luftwaffe. 3


Divide the number of 1600 by the 72% average

Looks to me like that is exactly what you did.. The loss rates on the graph for the GAF you quoted are total loss rates of Single Engine fighters. The total loss rate for SE fighters in the GAF in 1944 is given as 72%, the figure you used:

http://img175.imagevenue.com/loc1153/th_38553_loss_rates_122_1153lo.jpg (http://img175.imagevenue.com/img.php?image=38553_loss_rates_122_1153lo.jpg)


mean only 840 Fighter aircraft

My estimate shows a 300% loss rate to combat losses alone.

If we add the total losses we arrive at a 600% loss rate.

That agrees very well with historical figures.


Using the figure of 1150 aircraft, (the number of fighters based on the Western Front in Jan. '44)

But that is way off in the number of SE fighters available on the Western Front..

You have overestimated German SE fighter Strength by a factor of two, That mans your loss rates are highly inflated.

Here are the numbers of SE fighters in June 1944. This is a time period when the Luftwaffe was near peak strength.

http://img214.imagevenue.com/loc83/th_36501_Total_aircraft_Defense_of_the_Reich_122_8 3lo.JPG (http://img214.imagevenue.com/img.php?image=36501_Total_aircraft_Defense_of_the_ Reich_122_83lo.JPG)

That is ~450 SE fighters at peak strength.

When you have to keep making large assumptions we know to be false, for example:


Divide the number of 1600 by the 72% average loss rate for both fronts shown by your third chart, and we get 1152 fighter aircraft lost, which is actually pretty close to the average loss figure for the six month period of 1043 aircraft shown in your first chart. Remembering too, that the 72% figure includes non-combat losses.



but since the figure of 1043 is an average of COMBAT losses,

1152 – 1043 = 109 109/1152 * 100 = 9.46%

You figures show the GAF maintained a 10% combat loss rate on the Eastern Front. That is very far stretch of the imagination. One I am not willing to take.


With all due respect Crumpp, the key figures to be considered are the losses for each side. Ie. the 6259 figure for the Germans for a six month period, as compared to a 1293 figure for the USAAF for a 1 year period. It's pretty obvious one side is doing better than the other.

There simply is no reasonable way they are even close as you have essentially attributed the total losses of the GAF to the USAAF. No wonder you draw the conclusion you do, buzz.


Looking at this number, one might think the Luftwaffe had a very poor set of pilots who had real trouble with their landings.

There is no speculation, Buzz on the pilot training. It is a fact. I don't think you have any experience piloting real aircraft but trust me, you need training! The type and amount make a very large difference.

There is no doubt that this was largest contributing factor to German non-combat losses.

http://img42.imagevenue.com/loc859/th_37354_GAF_training_122_859lo.jpg (http://img42.imagevenue.com/img.php?image=37354_GAF_training_122_859lo.jpg)

http://img246.imagevenue.com/loc548/th_37359_GAF_training_operations_122_548lo.jpg (http://img246.imagevenue.com/img.php?image=37359_GAF_training_operations_122_54 8lo.jpg)

There is little doubt the Air War on the Western Front was a very hard fought battle of attrition.

All the best,

Crumpp

luftluuver
08-12-2008, 05:37 AM
That is ~450 SE fighters at peak strength.

That is serviceable, not what was on hand. There was 789 on hand.

Kettenhunde
08-12-2008, 04:11 PM
That is serviceable, not what was on hand. There was 789 on hand.

It is the number of aircraft that can be used to combat the enemy.

I am sure you are familiar with serviceability rates and do you understand that they maintain an average percentage value. In the GAF this hovered around ~50% mark so the 57% represented by the June serviceable number of 450 is well within acceptable ranges for our discussion.

All the best,

Crumpp

Buzzsaw-
08-12-2008, 10:24 PM
Originally posted by luftluuver:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">That is ~450 SE fighters at peak strength.

That is serviceable, not what was on hand. There was 789 on hand. </div></BLOCKQUOTE>

Salute Luftluver

Thanks for that info. I knew the figure I had quoted was for operational aircraft, and that there were additional aircraft listed as being on strength, but was not sure of the exact number.

Perhaps you could enlighten us as to how many Luftwaffe fighters were listed as being on strength in Jan. of '44 on the Western front?

Thanks Buzzsaw

luftluuver
08-12-2008, 10:35 PM
What ever you say Crumpp. Manipulate the numbers any way you want to.

It is interesting that Kurfurst states the maximum number of a/c available while Crumpp states the least number of a/c available.

Buzzsaw, you can try here
http://www.luftwaffe.no/SIG/OOB/Jan44-1.html

Buzzsaw-
08-12-2008, 11:18 PM
Salute Crumpp/Kettenhunde

I have reached the stage where I am not willing to commit a lot more time to discuss the issue of losses when it seems the other side is really not objectively considering the facts.

Your original insistence on using the number of intercepting fighters as a basis for establishing total strength cannot be substantiated by the facts. Luftwaffe fighters were based all over Germany, Holland, Belgium, France, Denmark and Norway. It is ludicrous to suggest that all of these widely based aircraft could participate in the same interceptions. Obviously fighters remained on the ground if a raid was directed at an area out of their range.

Now I see you have provided an actual strength table. Let's have a look at it and your claims.


Originally posted by Kettenhunde:

Here are the numbers of SE fighters in June 1944. This is a time period when the Luftwaffe was near peak strength.

http://img214.imagevenue.com/loc83/th_36501_Total_aircraft_Defense_of_the_Reich_122_8 3lo.JPG (http://img214.imagevenue.com/img.php?image=36501_Total_aircraft_Defense_of_the_ Reich_122_83lo.JPG)

That is ~450 SE fighters at peak strength.



First, the Luftwaffe was not at peak strength in June of '44, in fact, they were at the end of a period of decline, as a result of the losses suffered on the Western front during the very intensive battles against the 8th AAF.

Look at the chart you posted earlier again and note the decline from February and March to June:

http://img360.imageshack.us/img360/548/luftwaffestrength2uc2.jpg

But although the chart shows a decline, it unfortunately does not detail that the decline was most precipitous in the West. The Luftwaffe had just been decimated by the 8th AAF.


Second, your chart showing the Reichs Defence OOB may be accurate for those forces allocated to that organization, but it does not include all the Fighters based on the Western front on June 1st.

For example the following units were positioned to face the West, but are not listed on your chart:

JG-300 based in Germany

http://www.ww2.dk/air/jagd/jg300.htm

Note the strength on June 1st:

Stab/JG-300

http://www.ww2.dk/oob/bestand/jagd/bstjg300.html

2 aircraft

I/JG-300

http://www.ww2.dk/oob/bestand/jagd/bijg300.html

29 aircraft

II/JG-300

http://www.ww2.dk/oob/bestand/jagd/biijg300.html

32 aircraft

III/JG-300

http://www.ww2.dk/oob/bestand/jagd/biiijg300.html

27 aircraft

In total, JG-300 had 90 aircraft on strength.


Then there is JG-301 based in Germany

http://www.ww2.dk/air/jagd/jg301.htm

Strengths:

Stab/JG-301

http://www.ww2.dk/oob/bestand/jagd/bstjg301.html

3 aircraft

I/JG-301

http://www.ww2.dk/oob/bestand/jagd/bijg301.html

25 aircraft

II/JG-301

http://www.ww2.dk/oob/bestand/jagd/biijg301.html

20 aircraft

III/JG-301

http://www.ww2.dk/oob/bestand/jagd/biiijg301.html

21 aircraft

10/JG-301

http://www.ww2.dk/oob/bestand/jagd/b10jg301.html

10 aircraft

In total, JG-301 had 79 aircraft on strength


Then there is JG-77 based in Italy:

http://www.ww2.dk/air/jagd/jg77.htm

Strength

Stab/JG-77

http://www.ww2.dk/oob/bestand/jagd/bstjg77.html

6 aircraft

I/JG-77

http://www.ww2.dk/oob/bestand/jagd/bijg77.html

21 aircraft

II/JG-77

http://www.ww2.dk/oob/bestand/jagd/biijg77.html

54 aircraft

III/JG-77

http://www.ww2.dk/oob/bestand/jagd/biiijg77.html

31 aircraft

In total JG-77 has 111 aircraft.


From just these three Geschwader you overlooked, I get another 280 fighters facing West. I could list other units, for example JG-53 had Gruppes in Italy, France and Ploesti, also defending against Western Allied attacks, there are a number of smaller units, your chart does not list the twin engined fighter Geschwader, you haven't listed the Rocket Staffels, etc. etc., but frankly I am losing patience and interest...

In any case, with all due respect, it is clear that your accounting re. Luftwaffe fighter strength is mistaken.

I would suggest, again, that you take the time to go through the Luftwaffe site I have mentioned, and from which I got the above figures:

http://www.ww2.dk/

Bremspropeller
08-13-2008, 05:11 AM
Your definition of "west" and "east" is a bit off.

According to your logic, parts of JG52 and JG5 would also belong to the "west" statistics, yet they were clearly operating on the eastern front.

Kettenhunde
08-13-2008, 06:07 AM
But although the chart shows a decline, it unfortunately does not detail that the decline was most precipitous in the West. The Luftwaffe had just been decimated by the 8th AAF.


I don't understand that second sentence. It reads like you understand the chart does not address losses whatsoever, it just relates the strengths but in the very next sentence you just creatively invent information.


From just these three Geschwader you overlooked, I get another 280 fighters facing West

So you think the Luftwaffe could not determine it's own status??

The numbers I gave come right from the horse's mouth Buzzsaw.

I posted what the Luftwaffe says they had on hand June 3, 1944. It is different from what you say was on hand and used to attack the 8th USAAF.

I have to go with the Luftwaffe figures for their own aircraft.

JG301 was in refit and not available for combat. I pretty sure the GAF had a handle on the status.

All the best,

Crumpp

Kettenhunde
08-13-2008, 06:29 AM
What ever you say Crumpp. Manipulate the numbers any way you want to.

Are you a child? It is not "whatever I say" nor is there any manipulation of the numbers.

Tell us what you think would be reasonable given average serviceability like an adult instead of acting like a 3 year old who did not get his way.

Do you think 100% of the aircraft on hand are available to attack the enemy?

The facts I have from multiple sources say the GAF maintained about a 50% serviceability rate throughout the war. You can find specific days or times when this was better or worse, but 50% is a good representative figure.


Feldwebel Eric Bartel, who served as a Jagdgeschwader mechanic for much of the war, recalled that after just 17 days' action his staffel of 12 Bf 109Es from JG 77 had been reduced to just 5 or 6, including spares, mainly through mechanical failures and normal wear and tear, rather than enemy action.


In quality and general professionalism, it would be hard to fault the Luftwaffe maintenance organisation. It was certainly a match for the Royal Air Force. However, it was not organised for an attritional war and had made little provision for timely repair and salvage. It is also arguable that it was less flexible and had far more difficulty responding to changing circumstances. For example, as the war progressed, it became increasingly evident that maintenance personnel were finding it difficult to keep up with their parent units, much as Fighter Command would discover in 1940. Nevertheless, it would not be until late 1944 that the Luftwaffe introduced independent maintenance companies subordinate to the airfield rather than a particular flying formation to resolve this particular problem. [31]



http://findarticles.com/p/articles/mi_m0IBO/is_4_24/ai_...g_5?tag=artBody;col1 (http://findarticles.com/p/articles/mi_m0IBO/is_4_24/ai_74582443/pg_5?tag=artBody;col1)


All the best,

Crumpp

Buzzsaw-
08-13-2008, 06:06 PM
Originally posted by Kettenhunde:

I posted what the Luftwaffe says they had on hand June 3, 1944. It is different from what you say was on hand and used to attack the 8th USAAF.

I have to go with the Luftwaffe figures for their own aircraft.



I suggest you read what you present. The document you present is in English and is NOT a Luftwaffe report.

http://img214.imagevenue.com/img.php?image=36501_Total_...e_Reich_122_83lo.JPG (http://img214.imagevenue.com/img.php?image=36501_Total_aircraft_Defense_of_the_ Reich_122_83lo.JPG)

It's a compilation done in 1963 by a civilian who had access to some files. There is no way to assess how much this person missed, or what his level of access was. Certainly the document cannot be taken as a reliable source.


Originally posted by Kettenhunde:

JG301 was in refit and not available for combat.



Not correct.

JG-301 was active through June, if you bothered to look at the pages I referenced, you'd see the losses due to enemy action and other causes.

For example, I/JG-301

http://www.ww2.dk/oob/bestand/jagd/bijg301.html

In fact, JG-301 was one of the few Geschwader which was retained on Homeland defence, (along with JG-300) most of the other available Geschwader in the West were moved forward into France on orders from Hitler and told to contest the air over the beachhead. They failed completely and suffered huge losses.

Your offhand dismissal of sourced facts from a website whose contributors and supporters include such eminent Luftwaffe authorities as Christer Bergstrom indicates you are uninterested in real discussion and any real attempt at arriving at the factual truth of the situation in the air.

Rhetoric does not substitute for reality.

Sources for "The Luftwaffe, 1933 - 1945" (which ARE original documents)

http://www.ww2.dk/

Bundesarchiv-Militärarchiv, Freiburg.

Feldpostübersicht, RH 3/18 - 129. Has also been published by N. Kannapin in 3 volumes.

Schematische Kriegsgliederung, RH 2. Has also been published in Kurt Mehner's Geheime Tagesberichte der OKW, 12 vols. Exists in full, for the period 8.6.40 - 31.12.43, and partly for 15.4.44 - 7.5.45

Flugzeugunfälle und Verluste bei den fliegenden Verbänden , RL 2 III/184, 752 - 767, 1170 - 1198. The year 1944 is missing, but can be extracted from RL 2 III/852 (summarischen Verlustmeldungen).

Flugzeugunfälle und Verluste bei Schulen und Sonstige Verbänden, RL 2 III/769 - 784

Flugzeugbestand und bewegungsmeldungen, RL 2 III/874 - 882. Only covers the months 3.42 to 12.44. The rest is missing.

Stärkemeldungen der fliegenden Verbände, RL 2 III/1732 - 1765

übersicht über Soll, Istbestand, Einsatzbereitschaft, Verluste und Reserven der fliegenden Verbände, RL 2 III/700 - 734

Flakübersicht 11.43 - 12.44, RL 2 III/1119 - 1122

Kriegstagebücher

USAF Historical Research Agency, Maxwell AFB, Alabama

K1028F - Eastern front 1942, incl. KTB Fliegerführer Süd (2.42 - 8.42), extracts from Richthofen and Fiebig's diaries, monthly strength returns for entire eastern front, 60 page summary of 1. Luftwaffen-Flotilla (Siebel ferries) operations on Ladoga Sea

K1028G - Eastern front 1943, mainly VIII. Fliegerkorps operations

K1028Y & K1028X - KTB I. Jagdkorps (9.43 - 5.44) and KTB 5. Jagddivision (6.44).

A1128 - German Order of Battle - Statistics as of Quarter Years, 1938-45 (parts of the USAF Strategic Bombing Survey)

Kettenhunde
08-13-2008, 06:43 PM
Flugzeugbestand und Bewegungsmeldungen



Does not tell you whether they are in combat on a particular day.

You see any claims by JG301.

http://img516.imageshack.us/img516/650/jg301vp0.jpg (http://imageshack.us)
http://img516.imageshack.us/img516/650/jg301vp0.52d594332f.jpg (http://g.imageshack.us/g.php?h=516&i=jg301vp0.jpg)


Besides in their war diary it shows no activity for the first week of June.


Your offhand dismissal of sourced facts from a website whose contributors and supporters include such eminent Luftwaffe authorities as Christer Bergstrom and Tony Wood indicates you are uninterested in real discussion and any real attempt at arriving at the factual truth of the situation in the air.


Who do you think gave me that report? Try the same folks that did the website you are referencing Buzzsaw.

Your attitude stinks and you are constantly blustering without facts. I am done with you.

All the best,

Crumpp

Buzzsaw-
08-13-2008, 07:22 PM
Originally posted by Kettenhunde:

Who do you think gave me that report? Try the same folks that did the website you are referencing Buzzsaw.



In that was the case, I doubt whether they understand the context in which you are using the document, if indeed, it actually came from them, something I have my doubts about.

And if you have access to the documents which provide the basis for that website, not only are you biased, you are also dishonest, for witholding the information which would prove your case completely without merit.