Fw190 D-9 2.03 ata

[gripen]

Originally posted by Kurfürst
Actually the MT 215 makes your claim totally silly, but doh, facts do not bother you much... but, as HoHun suggested, if you are so keen sharing your ideas with others about the virtually endless list of DB/109 faults and failings, why dont you do it in a seperate thread and refrain here from spreading nonsense you dont back up later at all...

Well, it does not matter what I tell you, you want to keep your opinion. Could you please:

a. Get the article and check if what I say is true.

or

b. Ignore my postings if you don't like them.

or you can also do both.

gripen

[gripen]

Checked Monogram close up on Ta 154 and also there is claims about the Jumo 213A not giving claimed performance.

gripen

[Crumpp]

Checked Monogram close up on Ta 154 and also there is claims about the Jumo 213A not giving claimed performance.

Probably not much different from the Mustang Pilots claims of the aircraft not reaching factory performance.  Of course the Mustang was very dependant upon "fit and finish" unlike the FW-190.

Given field conditions, manufacturing defects, I have no doubt some FW-190's did not reach factory performance levels.  That is a logical and in all probability a true statement.  

To blanket classify every FW-190 or even the majority as substandard and unable to reach factory stated performance though is hardly logical.  A vast conspiracy to decieve the RLM would have to exist within the RLM test pilots, Focke Wulf, and the Luftwaffe.  Frankly it is a silly notion.

All the best,

Crumpp

[HoHun]

Hi Kurfürst,

>What I am wondering about is why curve 2 (Sonder/C3) and curve 4 (sonder/B4+MW) differ from each other..? I`d rule out different boost as it`s appearing on the whole altitude range.

That's probably the result of the different compression.

Remember that the boost pressure alone is only half the story - the supercharger compresses the intake air, but the piston compresses the air even further (actually, it does the lion's share of the compressing).

You want high charge pressure in the cylinder at the moment combustion starts - boost pressure outside the cylinder doesn't really mean anything.

Accordingly, with B4 + MW50 and standard compression, you'll get a standard power curve except in those regions where you can use MW50 to increase the boost pressure as long as your MW50 lasts.

If you have C3 available, you can increase combustion chamber pressure by some amount without having to worry about running out of MW50. That means you can increase the pressure in the cylinder - either by increasing the boost pressure or by increasing the compression.

The drawback of increasing the boost pressure is that it will only work below the original full throttle height, unless you change the supercharger or the supercharger gear ratio. Increasing compression, on the other hand, will give you a higher full throttle height with the same supercharger.

(Why not build a high-compression engine entirely without supercharger and let the piston do all the compressing? In WW1, engines like that were actually used, but they were less efficient than the supercharged engines that were introduced later.)

So we seem to have three different compression ratios with the same supercharger in our Focke-Wulf chart:

Curve 4: B4 + MW50, standard compression
Curve 2: C3, high compression, probably the 1 : 8,5 Naudet quoted
Curve 3: B4 + MW50, low compression

In fact, the curve 3 description is "Sondernotleistung mit A-Lader als Bodenmotor" = "special emergency power with A type supercharger as dedicated low altitude engine".

So it was MW50 injection, but the standard supercharger of the Jumo 213A, and the engine was turned into a dedicated low altitude engine by reducing the compression.

It's all logical, don't know why it took us years to figure out ;-)

Regards,

Henning (HoHun)

[HoHun]

Hi Crumpp,

>To blanket classify every FW-190 or even the majority as substandard and unable to reach factory stated performance though is hardly logical.  

I'd like to add that out of the 002, 006 and 043 aircraft, 002 was the only one with an engine that didn't match the Jumo 213A engine chart. The 006 and 043 tests matched the Jumo charts quite precisely.

Regards,

Henning (HoHun)

[gripen]

Originally posted by Crumpp
Probably not much different from the Mustang Pilots claims of the aircraft not reaching factory performance.

Monogram Close up on the Ta 154 seem to be quite well done book. Author (Jay P. Spenser) seem to have large amount of flight report from Fw and he also interviwed Sander and other FW personel. As an example he mention that he had complete flight reports of the Ta 154 V1. In the case of the Jumo 213A not delivering expected performance, author quotes pretty much directly a FW report.

Originally posted by Crumpp
Given field conditions, manufacturing defects, I have no doubt some FW-190's did not reach factory performance levels.  That is a logical and in all probability a true statement.  

We have here at least four separate reports where the Jumo 213A did not deliver expected performance and apparently no evidence that it actually could deliver expected performance. The test on 002 with MW 50 (reel 3481 in NASM) seem to be dated March 1945 and the Jumo 213A had been in quantity production about a year that time so the engine was probably quite standard.

Originally posted by HoHun
I'd like to add that out of the 002, 006 and 043 aircraft, 002 was the only one with an engine that didn't match the Jumo 213A engine chart. The 006 and 043 tests matched the Jumo charts quite precisely.

Actually not true, the 043 had lower FTH but HoHun claims that

"Daimler-Benz made two slight simplifications with regard to the diagram, drawing straight through the supercharger gear change, and slightly underestimating full throttle height."

In other words HoHun blames DB for poor match.

The 006 is so much slower than others that it is possible that it actually did run at lower MAP than the 002 and 043. That also explains higher FTH.

gripen

[gripen]

Ah... Just noted Naudet's post in the LEMB:

"And yes, 006 was used early with an "untuned" engine and a D12 airscrew.
As far as i understand the report "untuned" actually means an engine that was not put through several testflights to ajust boost pressure altittude and so on."

That pretty much confirms that the engine of the 006 might had been running at lower MAP and therefore it could reach higher FTH.

gripen

[Naudet]

The question whether the charger of the JUMO213A reached the proposed performance can not be answered currently.

Complains about lower FTH are written down in the Report of Nov '44 and it was ordered to check the chargers for production deficiencies.

Actually with the tests the problems are that multiple engines where used in each plane. FW noted the characteristics of those engines varied somewhat.
To be honest, while reading the tests i got the impression FW was not vary satisfied with the overall performance/quality of the JUMO213.

About the planes: 001 & 002 had the "Fahrwerksrestabdeckungen", while 006 did not have them. That might explain why 006 was a draggier airframe, it was not as "smooth" as the earlier maschines.

The tests with serial production planes lasted from around August '44 up to Feb/March '45. During March '45 FW send in a report summarizing all results from the D9 tests. Thats why you have so many tables with late dates.

Even though the D9 is by far my most favourite plane of WW2 i must admit that the overall picture the documents produce at the moment is that serial production planes were slightly underperforming due to engine problems.
If those problems could be solved cannot be answered yet.

I know these facts will heat up the discussion about plane performance in AH and i know even before this day ends the first voices will call for a performance reduction of the FW190D in AH.
But i would like to remind you all when rating the FW190D as a historic fighter plane, of the following: In AH +/- 5mph Topsspeed
really make a difference, cause you excatly know what your opponent is capable of, this was not the case in WW2 were the performance from plane to plane varied slightly and you only had a brief idea of the peak performance of you adversary.

P.S.: @Gripen the DB tests is a very odd one, it seems DB was using wrong data. They reported that Wk.-Nr. 210 043 engine was running at 1900PS, but that was not the case. Reported boost pressure, FTH, and speed of 043 show that the flights were done using take-off/emergency of 1750PS@1,5ata and not Erhoehte Notleistung.

[Crumpp]

Hohun says:
So it was MW50 injection, but the standard supercharger of the Jumo 213A, and the engine was turned into a dedicated low altitude engine by reducing the compression.

Makes perfect sense.

Gripen says:
We have here at least four separate reports where the Jumo 213A did not deliver expected performance and apparently no evidence that it actually could deliver expected performance. The test on 002 with MW 50 (reel 3481 in NASM) seem to be dated March 1945 and the Jumo 213A had been in quantity production about a year that time so the engine was probably quite standard.

No different from the investigation into the Mustang's problems.  It seems that the mustang could not achieve stated performance unless the machine had a very good fit and finish.  Something extremely hard to achieve in service use and something a frontline unit is unlikely to be able to maintain.  No solution presented itself during the war.  In fact the debate still rages today!

The tests with serial production planes lasted from around August '44 up to Feb/March '45. During March '45 FW send in a report summarizing all results from the D9 tests. That’s why you have so many tables with late dates.

Hey Naudet!
Interesting however I am not surprised.  

Without a doubt they were investigating ways to increase performance.  Additionally quality control was always a concern in wartime German aircraft manufacturing.  I have several reports on sabotage during production and investigation into substandard production of subcomponents of the FW-190A throughout the war.  Byproduct of the use of slave labor by the Nazi's and wartime philanthropy.  In fact we are working a display at the museum as parts of our aircraft were built with slave labor.  The German aircraft industry was very sensitive to quality control issues.  In fact, Focke Wulf maintained "quality control" example aircraft which were flown to various subcontractors’ assembly lines to demonstrate the standards Focke Wulf Bremen expected.

This was also a common practice with most aircraft manufacturers worldwide.  

Keep in mind, performance tests were also an ongoing fact of life in fighter development in any air force as well.   Designs were not static and for a manufacturer to not continue development was to invite both economic ruin for the company and defeat for the country.

As you well know, it's a long chain of events in the mass production of a complicated machine.  Any weak link can lower performance or lead to premature failure.  If this was not the case, new car dealerships would never need a service department!

BTW I have some goodies coming that may speak directly to this issue.  I located the engineering development team meeting minutes from Focke Wulf Bremen with the Geschwaders from Mid-1944 thru March 45.  These are meeting between the pilots, mechanics, and FW design team to get feedback on the aircraft performance in combat as well as suggestions for technical improvements.  Logistics’ is also discussed.  The previous reports I have are broken down by Luftflotte/JG.

All the best,

Crumpp

[gripen]

Originally posted by Naudet

I know these facts will heat up the discussion about plane performance in AH and i know even before this day ends the first voices will call for a performance reduction of the FW190D in AH.

I'm here merely promoting an idea that there is a remote possibility that real flight tests might give better picture of the performance of the plane and engine than any calculation or factory spec.

Regarding the performance of the AH Fw 190D, I can honestly say that no one else here can be more satisfied than me with it's current performance (and it's same in the case of the AH Bf 109G-2).

gripen

[Naudet]

Gripen, i fully agree with you. Real flight tests are giving the best picture, cause they are the only ones were production quality etc. shows it's effect.

And if it shows that the productions deficiencies of the JUMO213A were an issue due to the entire FW190D production, i myself would agree with a reduction of AHs D9 performance.

And as Crumpp mentioned in the late years of war the increasing amount of slave labor lead to problems with the quality control.
Additionally many planes/engines were license produced and those factories often did not show the same care for the production process as the orignal manufacture.
This is the case for the JUMO213A i.e. the first serial production batch that showed deficiences were not build by Junkers itself.
And for the FW190D it was known that planes from FW's own factory in Sorau were especially good with a very smooth surface finish.

My maininterest in this is - after years of research - no longer to promote a position of "this is the best plane", but to show that german aircraft specifications and design processes were based on a reliable and realistic data base and not some kind propaganda.

[Crumpp]

My maininterest in this is - after years of research - no longer to promote a position of "this is the best plane", but to show that german aircraft specifications and design processes were based on a reliable and realistic data base and not some kind propaganda.

They very much were based on reliable realistic data.  Many of today's innovations, from developing alloys such as Elektron, to today's industry leaders such as Drager, BMW, DB, and many others were leading their industry back then as well.  

Those documents arrived in the mail just a few hours ago.  There are several entries regarding the Jumo 213A and the Dora.

I will post scans on AAW in the "FW190 discussion group" for you.

The "my plane is best" agenda permeates these boards and is exactly why I am not keen to post nearly as much as in the past.  

There is always someone with "game" issue or agenda to push to include downright data manipulation.

All the best,

Crumpp

[LRRP22]

Crumpp,

What investigation are you referring to?  North American Aviation was well known for extremely good fit and finish.    VIII Fighter Command ground crews were equally well known for the care they took of their charges.  Polishing, waxing and repainting were the norm for 8th AAF fighters.

There seems to be a conventional wisdom which states that the Mustang suffered more than other fighters from operational use.  That CW is wrong.  I suspect it is based on the mistaken belief that the Mustang relied on actual laminar air flow over the wing to achieve its performance.  Not true.  As you no doubt know, the Mustang's sterling performance resulted from its radiator design and the laminar profile wing's excellent drag performance at high speed.  No production Mustang wing ever achieved true laminar flow.  

The fact is that both USAAF and RAF testing numbers met or exceeded the numbers supplied by NAA.  Even Mustang III FB377, which was received by the R.A.E. from 316 Sqn with a truly wretched surface condition (paintwork described as “in very poor condition” with eight coats of “badly chipped” paint on the wings), achieved 383 mph at SL fully combat loaded  at +25 lbs boost.  The much smaller Bf 109K-4's best-case estimated sea level performance was 6 mph slower with slightly more HP.  8th AAF historian Roger Freeman states that VIII FC squadron service P-51D’s exceed 430 mph in level flight at half combat fuel load.

Originally posted by Crumpp
Makes perfect sense.
 

No different from the investigation into the Mustang's problems.  It seems that the mustang could not achieve stated performance unless the machine had a very good fit and finish.  Something extremely hard to achieve in service use and something a frontline unit is unlikely to be able to maintain.  No solution presented itself during the war.  In fact the debate still rages today!
 

[Crumpp]

What investigation are you referring to? North American Aviation was well known for extremely good fit and finish. VIII Fighter Command ground crews were equally well known for the care they took of their charges.  

I am refering to an 8th AF investigation brought about by complaints from it's P51 squadrons that the aircraft was not reaching stated factory performance.

Are we really going to deny the "laminar flow" debate or enter it?  Aeronautical engineers have been arguing for decades now on this issue.

Polishing, waxing and repainting were the norm for 8th AAF fighters.

There is a reason it became the norm.  It takes a lot of extra work to polish a plane.  It is a difficult to maintain finish in a frontline unit.

It never had any weapon reliability issues either!

All the best,

Crumpp

[Naudet]

I will post scans on AAW in the "FW190 discussion group" for you.

Crumpp, i think i don't have access to that subsection of AAW currently.