Best Dogfighter Poll Revisited...

[Ivan1GFP]

My vote for the apex will probably go to the A-6, it sported more firepower than earlier versions (and cannon fire was of same muzzle velocity), while not as draggy as the A-7 and later. Though I'd delete the cowl MGs and install the external air ram intakes to improve high alt performance, that was an easy expedient.

Thanks for the pic, it is a handy reference.
The D-9 have had less power at altitude than A-9, it's supercharger was not better. The weight was less if it didn't sported outboard cannons. The hi-alt power of the BMW 801D2 remained the same from late 1942 to late 1944 (unless GM1 was used), by what time the 801S entered production.
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Hello Tomo Pauk,

Thanks for pointing out the deletion of the outboard cannon on the FW 190D-9. I had completely missed that factor in the quotes for loaded weights.
FW 190A-8 - 4395 KG
FW 190A-9 - 4420 KG but it works out to only 4150 KG without the outboard guns
FW 190D-9 - 4270 KG

- Ivan.

 

[Ivan1GFP]

Bluntly, a lot of the critcism of the tests of the FW190 vs Allied aircraft shrieks of special pleading. And don't get me started about the "brilliant fan-cooled engine." If everybody else manages without a power-sucking fan, why is it so smart to add one?

Hello Swampyankee,
There are actually a couple memos of the time commenting about how flight performance tests of captured aircraft were not a good idea because of the lack of spares and lack of ability to maintain the aircraft. The particular "FW 190A-5/U4" tested in this report was at best a "well-used" aircraft. It was captured April 1943 and had gone through testing in England before transfer to the United States.

Regarding the "Brilliant Fan-Cooled Engine":
It allowed for good cooling under all conditions (once other issues were worked out) even with a very close cowling and a small cowl opening. At low speeds, it would require about 70 HP to spin but at high speed the airflow through the cowl opening was driving the fan and the actual power cost was negligible.
Another "Brilliant Idea" that turned out to be not so brilliant was the mounting of the oil cooler in a ring at the front of the cowl. It made for a very low drag assembly but also proved to be quite vulnerable to weapons fire and leaking oil directly onto a hot engine did not usually turn out well.

- Ivan.

 

[DarrenW]

...The particular "FW 190A-5/U4" tested in this report was at best a "well-used" aircraft....

But weren't the speeds attained during these tests at least commensurate with the tests performed by the Germans on new production machines? I'm talking without any type of added emergency boost system of course, as it wasn't utilized during the testing (I didn't notice it mentioned anyway). If this is true then it wouldn't be stretch to believe that it was in decent enough condition and could provide a reasonable example of an operational machine in current use by the Luftwaffe.

 

[Ivan1GFP]

But weren't the speeds attained during these tests at least commensurate with the tests performed by the Germans on new production machines? I'm talking without any type of added emergency boost system of course, as it wasn't utilized during the testing (I didn't notice it mentioned anyway). If this is true then it wouldn't be stretch to believe that it was in decent enough condition and could provide a reasonable example of an operational machine in current use by the Luftwaffe.

The speeds quoted here are pretty consistent with the typical specifications given for the type and with reports by the Germans themselves.
The question is whether or not the Germans normally measured maximum speed with emergency power. I believe that they did not.
The Americans typically quoted maximum speeds with emergency power and that is pretty much what we are seeing here.
Japanese, FWIW, did not use emergency or take-off power for their performance tests.
The way I interpret this is that if you have three aircraft with identical book performance from their respective nations' specifications, in actual combat when everyone was running emergency power, the Germans and Japanese aeroplanes would actually have an advantage.

- Ivan.

 

[tomo pauk]

The speeds quoted here are pretty consistent with the typical specifications given for the type and with reports by the Germans themselves.
The question is whether or not the Germans normally measured maximum speed with emergency power. I believe that they did not.
The Americans typically quoted maximum speeds with emergency power and that is pretty much what we are seeing here.
Japanese, FWIW, did not use emergency or take-off power for their performance tests.
The way I interpret this is that if you have three aircraft with identical book performance from their respective nations' specifications, in actual combat when everyone was running emergency power, the Germans and Japanese aeroplanes would actually have an advantage.

- Ivan.

German fighter aircraft were always using emergency power (usualy called 'Notleistung') for maximum performance, tests included, eg. 5 min worth for DB 601A/E/605, 3 min for BMW 801C/D, 5 min for 801S. The only time period they will not do it was when it was explicitely banned, for example on DB 601E (~6 months), or 605A (~15 months). Engine setting that improved boost (over-boosting), and thus power, was called 'Special emergency power' ('Sondernotleistung', used MW 50, worked both on 87 and 100+ oct fuel) and 'Increased emergency power' ('Erhoehte Notleistung') that took advantage of high oct fuel resistance for detonantion. For the BMW 801D, the 'Increased emergency power' went to 1.58 ata in low S/C gear and 1.65 in high gear, power rising up to 1900 and 1700 PS for low and high gear respectively.

Hopefully we'd get Japanese A/C test reports translated, in order to better understand how they actually tested their fighters. I myself don't believe they didn't make tests with max engine power.

 

[DarrenW]

Hi Ivan and Tomo,

So in a nutshell, if the testing of this particular FW-190 were performed with boost it would have been even faster. I fully agree with this assumption. However this doesn't take away the fact that this particular airframe hit speeds similar to what one would expect from a A-5 model, without the application of some form of emergency boost. I have heard that a typical war emergency injection system will add about 10 - 15% more engine horsepower and in most cases will increase the speed of the airplane by 10-15 mph (15 to 25 kph). To me this proves that the aircraft tested by the US Navy was in decent shape and was not a worn-out machine as implied earlier in this thread. What are your thoughts on this?

 

[Hansie Bloeckmann]

IMO- FDR and George Marshall had a real tough call to make. Granted, Hitler had a two-front war in the ETO, after June 1941 and the ill-advised operation Barbarosa- but the USA had a two-front war with the two oceans between Europe and Japan to contend with. All of Hitler's war production in the early era of WW2 was centralized in Germany and neighboring countries. Japan's needed raw materials (iron ore, coal, rubber and petroleum) had to be shipped to the Japanese mainland. I can't say whether the USA from Dec 1941 until May 1945-then Sept. 1945, "favored" an emphasis on the ETO efforts, or the PTO. I do believe that Winston Churchill highly influenced FDR, and was a bit underhanded in his dealings with Stalin, probably believing that Stalin would bleed Russia of military manpower (soldier's lives sacrificed) to a much greater extend than would FDR, in sacrifice of American lives to gain the ultimate victory in both Theaters.

 

[tomo pauk]

Hi Ivan and Tomo,

So in a nutshell, if the testing of this particular FW-190 were performed with boost it would have been even faster. I fully agree with this assumption. However this doesn't take away the fact that this particular airframe hit speeds similar to what one would expect from a A-5 model, without the application of some form of emergency boost. I have heard that a typical war emergency injection system will add about 10 - 15% more engine horsepower and in most cases will increase the speed of the airplane by 10-15 mph (15 to 25 kph). To me this proves that the aircraft tested by the US Navy was in decent shape and was not a worn-out machine as implied earlier in this thread. What are your thoughts on this?

The ww2 aircraft always use boost duing any flight test that is to determine performance. Boost was provided by supercharger, and all military engines in ww2 and decade before were outfitted with supercharger of that or this layout and capability (Hellcat and Corsair used much better superchargers than Fw 190As, thus they were competitive despite the bigger form factor and weight). US engines also used greater boost during the test, all 3 engines pushed 'by the book'.
The problem I see with speed vs. power of the Fw 190 in the test is that it should be going faster on the stated boost & RPM, 1.42 ata and 2700 RPM. German data shows easy 370 mph between 5000 and 10000 ft, and 360 mph at SL. Or, some 15 mph faster than it was the case with USN test.
The Fw 190A did not used water/alcohol injection for oveboost (going beyond 1.42 ata). It took advantage of the ever-improving octane/performance rating of the fuel* so the throttle will be held open under the rated altitudes, thus the engine will get more air supplied by supercharger. Power increase of ~200 PS was gained under the rated altitudes, speed went up by up to 15 mph.

*feature used by Allied angines, too

 

[swampyankee]

The US has a long history of being isolationist regarding Europe but being quite the opposite in South and Central America and China. Despite this, the US had significantly more trade with Europe than with China or Asia, in general.

There were a lot of reasons why the relations between the US and Japan got progressively worse until the start of WW2; some of these almost certainly involve US racial prejudices, but the main reason was a quite proprietary relationship the US had with China.

 

[pbehn]

A "war on two fronts" is an old military nightmare, not only for Germany. However increasingly Germany had a war on multiple fronts. Stalingrad and El Alamein were at about the same time, as were Kursk and the invasion of Italy. Rome fell at the same time as D Day and Bagration, while through all of this there were the wars on the sea and in the air. That is the major conflicts there were many others in places like Greece Norway, the Balkans and Eastern Europe.

 

[swampyankee]

A "war on two fronts" is an old military nightmare, not only for Germany. However increasingly Germany had a war on multiple fronts. Stalingrad and El Alamein were at about the same time, as were Kursk and the invasion of Italy. Rome fell at the same time as D Day and Bagration, while through all of this there were the wars on the sea and in the air. That is the major conflicts there were many others in places like Greece Norway, the Balkans and Eastern Europe.

And Germany voluntarily put itself into that very situation twice in a generation.

 

[pbehn]

And Germany voluntarily put itself into that very situation twice in a generation.

I worked in Germany and it goes back much further than the two world wars, in fact back to before the Thirty Years War. If you had a mind to you could call the Napoleonic wars a World War and Prussia was on the side of Great Britain in that, while in the Franco Prussian war, France declared.

This has nothing to do with WW"s best dogfighter.

 

[swampyankee]

I worked in Germany and it goes back much further than the two world wars, in fact back to before the Thirty Years War. If you had a mind to you could call the Napoleonic wars a World War and Prussia was on the side of Great Britain in that, while in the Franco Prussian war, France declared.

This has nothing to do with WW"s best dogfighter.

Absolutely true. Neither does the War in the Pacific, which was brought up by others. The only political concern is that the FW190 and Bf109 benefited by Germany's intervention in the Spanish Civil War, in development of tactics and basic specifications of their fighters.

 

[DarrenW]

I never realized that the "normal" speeds attained by most A-5 aircraft was so high. But then again it was a relatively light aircraft with a wing of minimal area and fuselage that had much less wetted area than either the Hellcat or Corsair. And given that the Hellcat weighed pratically fifty percent more than the German machine and had a much larger wing area, I would actually expect the FW-190A-5's speed to be even higher than the numbers quoted in the last post. It leads one to believe that the it wasn't as aerodynamically advanced as either the F6F or F4U.....

 

[pbehn]

After the F6F aircraft design started to reverse and never recovered.

 

[Ivan1GFP]

German fighter aircraft were always using emergency power (usualy called 'Notleistung') for maximum performance, tests included, eg. 5 min worth for DB 601A/E/605, 3 min for BMW 801C/D, 5 min for 801S. The only time period they will not do it was when it was explicitely banned, for example on DB 601E (~6 months), or 605A (~15 months). Engine setting that improved boost (over-boosting), and thus power, was called 'Special emergency power' ('Sondernotleistung', used MW 50, worked both on 87 and 100+ oct fuel) and 'Increased emergency power' ('Erhoehte Notleistung') that took advantage of high oct fuel resistance for detonantion. For the BMW 801D, the 'Increased emergency power' went to 1.58 ata in low S/C gear and 1.65 in high gear, power rising up to 1900 and 1700 PS for low and high gear respectively.

Hopefully we'd get Japanese A/C test reports translated, in order to better understand how they actually tested their fighters. I myself don't believe they didn't make tests with max engine power.

Hello Tomo Pauk,
I had started writing a different post and then decided to do a lot more poking around in the images of test reports that I have collected. Many of them are quite hard to read unless you are looking for something very specific such as 'Start u Notleistung". Turns out that the speed tests do show "Take-Off and Emergency Power" as you stated. What is even more interesting is that the manifold pressure for "Start und Notleistung" for the A-5 is listed as 1.42 ATA and the speed depending on the particular graph is anywhere from just over 640 KPH (just under 400 MPH) to 670 KPH or 416 MPH. It is hard to tell which is correct....

The FW 190A-5 tested in this report was using 1.42 ATA or 42.5 inches Hg.
Problem is that 42.5 inches Hg is 1.46 ATA and 1.42 ATA is 41.3 inches Hg....

On some models there was also C3 injection which gave around 2100 PS.

- Ivan.

 

[Hansie Bloeckmann]

A "war on two fronts" is an old military nightmare, not only for Germany. However increasingly Germany had a war on multiple fronts. Stalingrad and El Alamein were at about the same time, as were Kursk and the invasion of Italy. Rome fell at the same time as D Day and Bagration, while through all of this there were the wars on the sea and in the air. That is the major conflicts there were many others in places like Greece Norway, the Balkans and Eastern Europe.

Points well taken. I suppose one could also argue that Japan was fighting on multiple fronts as well in the PTO- all of the Allied "island hopping" campaigns, plus China, Burma, and after May 5th 1945, the potential threat from Russia as well.

 

[swampyankee]

I never realized that the "normal" speeds attained by most A-5 aircraft was so high. But then again it was a relatively light aircraft with a wing of minimal area and fuselage that had much less wetted area than either the Hellcat or Corsair. And given that the Hellcat weighed pratically fifty percent more than the German machine and had a much larger wing area, I would actually expect the FW-190A-5's speed to be even higher than the numbers quoted in the last post. It leads one to believe that the it wasn't as aerodynamically advanced as either the F6F or F4U.....

I think that something like this can be demonstrated by an objective comparison between the steady state climb performance (for piston aircraft, rate of climb is frequently a better indicator of aircraft drag than is top speed), maximum, and cruise speeds and payload/range performance. American aircraft, like the P-40, were consistently heavier than many, not just German, contemporaries and had much closer performance than would be the case if the general level of aerodynamic "cleanliness" was similar. I don't think US aerodynamicists were that much better than German (or British, Japanese, Italian, Soviet, etc: aerodynamics were an international community pre-WW2);

Incidentally, I don't think it's so much being aerodynamically advanced as having greater effort spent on a lot of gritty, low-level details, and taking more benefit from NACA airfoil research.

As an aside, NACA had at least four families of airfoils produced by systematic variation of thickness and camber:

• The four-digit airfoils, like the 44xx series
• The five-digit series, like the 23012 (used on the Bonanza, among other aircraft), which were modified for somewhat lower pitching moments; the FW190 used the 23015.3 at the root and the 23009 at the tip
  
• The 1-series, which were not used for many aircraft, but were used on propellers
  
• The 6-series, like the 64A212, which were designed around pressure distributions to get some region of laminar flow

Earlier families, like the 2R1 series (used by the Bf109) and the Clark Y (and YH; the latter used on the Hurricane) were also used.

 

[tomo pauk]

I never realized that the "normal" speeds attained by most A-5 aircraft was so high. But then again it was a relatively light aircraft with a wing of minimal area and fuselage that had much less wetted area than either the Hellcat or Corsair. And given that the Hellcat weighed pratically fifty percent more than the German machine and had a much larger wing area, I would actually expect the FW-190A-5's speed to be even higher than the numbers quoted in the last post. It leads one to believe that the it wasn't as aerodynamically advanced as either the F6F or F4U.....

I'm not sure where it came from that F6F and F4U were that aerodynamically advanced.
The reason why the F4U was capable to keep pace with Fw 190, and F6F barely so in performance figures, was the engine that provided 15-20% more power at any choosen altitude.

 

[Ivan1GFP]

I never realized that the "normal" speeds attained by most A-5 aircraft was so high. But then again it was a relatively light aircraft with a wing of minimal area and fuselage that had much less wetted area than either the Hellcat or Corsair. And given that the Hellcat weighed pratically fifty percent more than the German machine and had a much larger wing area, I would actually expect the FW-190A-5's speed to be even higher than the numbers quoted in the last post. It leads one to believe that the it wasn't as aerodynamically advanced as either the F6F or F4U.....

Hello DarrenW,

Judging by the standards of the European Theatre, the FW 190A-5 wasn't particularly fast for the time.
From the standpoint of advanced aerodynamics, it actually wasn't bad. The closely cowled engine with a spinner worked quite well as compared to American attempts to do similar things. Note that the F4F Wildcat prototype had a spinner but discarded it because of cooling issues. The fairly thin fuselage used engine exhaust to make up for the cross sectional change at the cowl and was an idea that was later copied by the Kawasaki Ki 100 when it switched from an inline to a radial engine.
The F6F is actually a much better example of lack of aerodynamic refinement. It was a great fighter and had all the necessary features to fight its intended opposition, but ease of construction (such as with lap joints) took priority over aerodynamics which is probably why it was so slow for the amount of power that it had. No matter what Grumman claimed, the Corsair was a bit faster on the same power.
Note that in this test, the F4U-1D had the stock propeller which had issues. In the field, they were often replaced with the propeller used by the Hellcat and performance was improved. This was specifically mentioned at the end of the report.

- Ivan.