Some data comparison between FW 190 A-3 vs Yak-1 (1942)

[Kurfurst]

IIRC then according to Matt and JtD "R" stands for "Rollen", "A" for "Abheben" and "St" for "Start".

I think there is something strange with the Charles Meudon polar posted earlier: If you look at the Camax with full flaps it’s only about 1.48. Now the German drag table lists Camax as 1.58 and as Matt has shown earlier this is with 60 degrees of flaps as well so the CM measurements are 0.1 off from the figures listed in the table.

 

This discrepancy may either be due to Reynolds number effects or measurement errors. Anyway, it shows that the Charles Meudon measurements should be taken with a grain of salt.

 

Speculation only without evidence, as usual...

[ZachariasX]

 

 

Speculation only without evidence, as usual...

Polars and tables are "not evidence"? What is "evidence"?

[Kurfurst]

Polars and tables are "not evidence"? What is "evidence"?

 

Well the 190A CL is modelled after the measured polars, so rejoice brother, everything's fine. 

 

The speculation is that these measured polars are inaccurate. This speculation is so far completely unsupported.

 

Of course there are some who simply have a known penchant (and not much else) to just take the highest figure and simply ignore the rest.

 

For Christ's sake, they are even guessing what CaR, CaA and CaSt stand for in that fabulous table they take as a gospel...

 

Serious discussion starts IMO with the whole paper being posted, not cherry picked and freely 'interpreted'.

[ZachariasX]

Ah ok then. I was just interested in your view of things.

 

Being at this, what do CaR, CaA and CaSt stand for, given you suggest they assume wtong? Is that table wrong/false/fabricated? If so, why? I don't mind at all being stringent on data. You have to be.

[Matt]

 

For Christ's sake, they are even guessing what CaR, CaA and CaSt stand for in that fabulous table they take as a gospel...

 

Assuming that you include me with "they", i only claim to know that the CaA means "Abheben-Ca", atleast Focke-Wulf thinks so. And i'm assuming Focke-Wulff knows what they ment with it at least as well as you do.

 

As far as i'm concerned, the Cl values of Widerstandsdaten table don't represent the actual values of the plane in question and shouldn't show up in these discussions at all. JtD explained that already on the previous page.

Edited September 30, 2016 by Matt

[II./JG77_Manu*]

As far as i'm concerned, the Cl values of Widerstandsdaten table don't represent the actual values of the plane in question and shouldn't show up in these discussions at all

 

Of course they should. They clearly show that all 190s have the same Clmax. That's an important aspect to prove. 

Edited September 30, 2016 by II./JG77_Manu*

[Matt]

Of course they should. They clearly show that all 190s have the same Clmax. That's an important aspect to prove. 

I don't see what difference it makes wether or not all 190s have the same Clmax, as long as there's no good source for the Clmax for any Fw 190 variant. I also don't think that anybody doubts that the Clmax between the Fw 190 variants is more or less the same. So i can't see the important aspect in this.

 

And coincidentally, the 1.58 Camax is exactly the same Camax (to two decimals!) which in this Focke Wulff document is used only as a save Camax in landing configuration for calculating the landing speed.

I personally have reasonable doubt that the 1.58 Camax in the Widerstandsdaten table now suddenly means something else and that it is of any use in this discussion, but if you want to convince the devs, you can of course give it a try.

 

EDIT: BTW, in the other topic you post  Yoyos explanation and how it should be used and now you think this table is of any use, even though Yoyo says in the same topic that it's not the case. You seem to be a bit selective in this case.

Edited September 30, 2016 by Matt

[II./JG77_Manu*]

 

 

BTW, in the other topic you post  Yoyos explanation and how it should be used and now you think this table is of any use, even though Yoyo says in the same topic that it's not the case. You seem to be a bit selective in this case.

No i am not. The sheet is just the "proof" for the FM defense army of this Forum, who want to have "sources" for everything, like the source describing that the sky is blue  

It's proof that the CLmax is the same for all 190s. Good that we have this proof. 

 

I also don't think that anybody doubts

There have been far more obvious cases with enough people who doubted facts "without proof"

[Matt]

It's proof that the CLmax is the same for all 190s. Good that we have this proof. 

 

Can you name one person who stated otherwise? Why does that make a difference?

 

However...

 

 

 

There have been far more obvious cases with enough people who doubted facts "without proof" 

... to be 100% accurate here, that statement is false because the fuselage of the D series was not the same as that of the A series and that difference alone would have enough impact on the Clmax to make a measurable difference. So that alone can be considered as proof, that the table is worseless. 

Edited September 30, 2016 by Matt

[II./JG77_Manu*]

 

 

So that alone can be considered as proof, that the table is worseless. 

Says the guy who doesn't even know the difference between dive acceleration and level speed acceleration (hallo gravitiy )  

[Holtzauge]

To be diplomatic, I think you both have a point: The table will not help in determining the no flap Clmax of the Fw-190 like Matt pointed out (Incidentally, I think that may have been why the devs dismissed the previous report because a no flap Clmax of 1.58 for the Fw-190 is unreasonably high). OTOH as Manu says, it does show that the Germans assumed the same Clamx at the 60 degree flap setting for the Anton and Dora which is useful since there have been some that claim you cannot compare the two even if they have the same type of wings.

[Matt]

Says the guy who doesn't even know the difference between dive acceleration and level speed acceleration (hallo gravitiy )  

Yeah that was a brain fart, happens once in a while when you get older and work alot.

 

I know the difference quite well actually and could calculate the dive acceleration for each plane if you would be intrested (with some simplications, like prop effiency etc.).

Edited September 30, 2016 by Matt

[Crump]

I don't see what difference it makes wether or not all 190s have the same Clmax, as long as there's no good source for the Clmax for any Fw 190 variant. I also don't think that anybody doubts that the Clmax between the Fw 190 variants is more or less the same. So i can't see the important aspect in this.

 

And coincidentally, the 1.58 Camax is exactly the same Camax (to two decimals!) which in this Focke Wulff document is used only as a save Camax in landing configuration for calculating the landing speed.

post-3376-0-76517400-1459608622.jpg

I personally have reasonable doubt that the 1.58 Camax in the Widerstandsdaten table now suddenly means something else and that it is of any use in this discussion, but if you want to convince the devs, you can of course give it a try.

 

EDIT: BTW, in the other topic you post  Yoyos explanation and how it should be used and now you think this table is of any use, even though Yoyo says in the same topic that it's not the case. You seem to be a bit selective in this case.

 

 

Very common thing to do when calculating landing speed.  The only problem I see is that forum members seem to think Landing Speed = Stall Speed.  It physically cannot be the same.  We would not land our airplane, we would die in a big fireball as our plane dropped out of sky short of the runway.

 

CL = Weight/(dynamic pressure* Reference Area)

 

Dynamic pressure @ 165kph IAS = 26.85psf

 

Weight At 3800Kg = 8377lbs

 

Velocity at 165kph = 89 Knots

 

CL = 8377lbs/(26.85psf*89) = 1.58

 

Notice the lift formula does not care what the configuration of the aircraft is at the time.  In order to support 8377lbs of weight we must generate 8377lbs of lift.  It does not matter if that lift comes from flaps being at 60 degrees, a clean wing, or the pilot flapping his arms.  That point is selected because of where the lines intersect on the chart grid makes it easy to get exact numbers.  The speeds change with weight.

 

That exactly matches the instructions to the pilot on what speed to land use to safely land the airplane found in the FW-190A8 Operating Instructions:

 

 

A coefficient of Lift of 1.58 was used to construct the landing speed chart.  Therefore, it cannot be the 1G stall speed of the aircraft in landing configuration.

 

 

What it does tell us is that the 1G stall CLmax is equal to the Touchdown  or Landing Speed.  

 

That is easily seen in the RAF trials where they list the stall speed in clean configuration and the touchdown speed.  So, both the Focke Wulf data and the Allied data agree.

 

 

Touchdown Speed = Landing Speed = 1G Clean Configuration Stall Speed

 

A little proportional thinking shows us that the RAF found the Landing configuration stall speed to be 105/110 = .95 or 5% below the Landing Speed.  If you account for position error then our margin increases to the normal 10% buffer found in typical aircraft performance landing calculations.

 

That also explains why Grumman and Focke Wulf have the same CLmax for the clean wing using the same airfoil selection in their design.

 

 

 

 

 

 

Once again, the Allied data and the Focke Wulf data agree unless we want to conclude that the way the physical world works is altered when one crosses the Atlantic Ocean.

[unreasonable]

 

CL = Weight/(dynamic pressure* Reference Area)

 

Dynamic pressure @ 165kph IAS = 26.85psf

 

Weight At 3800Kg = 8377lbs

 

Velocity at 165kph = 89 Knots

 

CL = 8377lbs/(26.85psf*89) = 1.58

 

 

Why are you using the speed as the term for the reference area? What is that 89 Knots doing there? Should it not be an area?

(197.46sqft to get 1.58).

 

8377/(26.85*89) = 3.51

[Crump]

Why are you using the speed as the term for the reference area? What is that 89 Knots doing there? Should it not be an area? (197.46sqft to get 1.58).   8377/(26.85*89) = 3.51

 

[Edited]

[Crump]

[Edited]

 

Edited October 5, 2016 by Bearcat

[unreasonable]

 

http://forum.il2sturmovik.com/topic/25513-bmw801-ata-drop-v-altitude/?p=396124

 

I am more interested in your comments on this since you and JtD contributed so much to the screwing up of the games depiction of the system!!

unreasonable?

 

 

You give us far too much credit! The developers decided how to portray the KG's operation all on their own months before any of us saw the result in game, nothing to do with me, or I expect JtD.

 

If you are unhappy with their decisions, take it up with them.

[Crump]

 

 

The developers decided how to portray the KG's operation all on their own months before any of us saw the result in game, nothing to do with me, or I expect JtD.

 

 

Oh, so a bug report should be submitted?

 

 

 

 

 You can do that because the pressure capsules in the linkage downstream of the main Kommandogerat control valve compensate for atmospheric conditions and maintain the correct linkage calibration point in the heat of summer or the dead of winter.  

[Wulf]

To be diplomatic, I think you both have a point: The table will not help in determining the no flap Clmax of the Fw-190 like Matt pointed out (Incidentally, I think that may have been why the devs dismissed the previous report because a no flap Clmax of 1.58 for the Fw-190 is unreasonably high). OTOH as Manu says, it does show that the Germans assumed the same Clamx at the 60 degree flap setting for the Anton and Dora which is useful since there have been some that claim you cannot compare the two even if they have the same type of wings.

 

Just in case there's some misunderstanding on the part of those people not much interested in the 190; the FW 190 D doesn't use the same 'type' of wing as the A series.  It uses exactly the same wing as the 190 A, or more correctly, the same wing as introduced with the A-6.

[JtD]

There were some differences along the leading edge where the wing joins the fuselage. For obvious reasons. Structurally that's minor, but since the region is aerodynamically quite relevant, I wouldn't say A and D wings are exactly the same.

[Wulf]

There were some differences along the leading edge where the wing joins the fuselage. For obvious reasons. Structurally that's minor, but since the region is aerodynamically quite relevant, I wouldn't say A and D wings are exactly the same.

 

Well I have to confess that's news to me.  I wasn't aware of any changes to the leading edge, in the area of the wing root or anywhere else for that matter.  Is there a reference that I could have a look at? I'm not doubting you, I'm just not aware of the modification.

[MiloMorai]

 

[JtD]

It's a statement in the Fw190 technical description, outlining the differences between the individual models. It states as a difference between A-9 and D-9 "the forward sheeting as transition to the engine cover". Leaves me a bit clueless about the details, but it was important enough for Fw to write it down.

 

Edit: Added a line of explanation, accidentally deleted in initial post.

Edited October 8, 2016 by JtD

[Wulf]

It's a statement in the Fw190 technical description, outlining the differences between the individual models. It states as a difference between A-9 and D-9 "the forward sheeting as transition to the engine cover". Leaves me a bit clueless about the details, but it was important enough for Fw to write it down.

 

Edit: Added a line of explanation, accidentally deleted in initial post.

 

 

Thanks.

[MiloMorai]

The D-9 deleted the extra piece that can be seen in the photo making for a smoother transition.

 

 

[Crump]

That is aerodynamically insignificant.  It simplifies manufacturing.

 

 

Just in case there's some misunderstanding on the part of those people not much interested in the 190; the FW 190 D doesn't use the same 'type' of wing as the A series.  It uses exactly the same wing as the 190 A, or more correctly, the same wing as introduced with the A-6.

 

Aerodynamically the wings are the same from the FW-190A0 thru FW-190D9. 

There were changes in weapon cover installations, control surfaces, and dimpling that do effect the specific results.  

 

That is not a change to the wing design itself.  It was still the same airfoil selection and aerodynamic twist.

 

Putting tape over the gunports of a Spitfire does not change the wing design but it certainly has a large effect on the wing behaviors.

[MiloMorai]

Aerodynamically the wings are the same from the FW-190A0 thru FW-190D9.

 

One would think that a person who is such a stickler for accuracy/precision/detail would at least get the airplane designations correct.

 

He even posted a graphic with the correct designations here, http://forum.il2sturmovik.com/topic/25504-lets-put-together-new-report-fw-190a-3-han/page-3 so no excuse for getting the designations wrong.

[Crump]

The correct designation is actually 8-190...that is what the Luftwaffe used.

 

Wait!!  It is contextual.  I think the reader understands which airplanes I am talking about so communication is performed.

 

 

If it confuses you as to which airplanes are under discussion, just let me know and I will add the hyphen for you.

Edited October 8, 2016 by Crump

[Bert_Foster]

Nit picking I know but A0-A5 had wingspan 10.393m A6 -D9 had wingspan 10.506m

[JtD]

I've recently seen first hand sources that state that, but I think it's a simplification. I'm certain A-2 and later all had the 10.51, but I've seen so many sources state 10.38 for the A-1 that I'm not convinced that 10.51 commonly stated is accurate. Oddly enough, this bit is often skipped in books on the Fw190, usually they go with 10.51 from V5g onwards, and before that mention the ~9.50 small wing only. I haven't taken the time to find out the details on that.

[Wulf]

I've recently seen first hand sources that state that, but I think it's a simplification. I'm certain A-2 and later all had the 10.51, but I've seen so many sources state 10.38 for the A-1 that I'm not convinced that 10.51 commonly stated is accurate. Oddly enough, this bit is often skipped in books on the Fw190, usually they go with 10.51 from V5g onwards, and before that mention the ~9.50 small wing only. I haven't taken the time to find out the details on that.

 

 

Maybe I'm being overly simplistic about this but it's my understanding that a new wing; stronger, lighter, bigger was introduced with the A-6 to a) improve the bomb-carrying and b) to fight weight-creep.

 

As far as I know, this remained the standard from A-6 to D-9 (not so sure about the A-10 which may have had a somewhat bigger wing in some variations).

Edited October 8, 2016 by Wulf

[NZTyphoon]

I've recently seen first hand sources that state that, but I think it's a simplification. I'm certain A-2 and later all had the 10.51, but I've seen so many sources state 10.38 for the A-1 that I'm not convinced that 10.51 commonly stated is accurate. Oddly enough, this bit is often skipped in books on the Fw190, usually they go with 10.51 from V5g onwards, and before that mention the ~9.50 small wing only. I haven't taken the time to find out the details on that.

The details are as follows: (from Smith & Creek Fw 190 Volume One 1938-1943. Pages 66 thru 70.)

 

The original "small wing" Fw 190 V5 (0005), the first 190 to be powered by the BMW 801, first flew on May 15 1940; after a total of seven flights it crashed and was written off on September 9 1940. The small wing spanned 9.515 m (31 ft 2½ in) with an area of 14.9 m² (160.382 sq ft). Fw 190s with the small wing were the prototypes V1 thru V6 and pre-production A-0s W.Nr. 0007 to 0015.

 

The V5g was actually a pre-production Fw 190A-0, W.Nr.0016, that first flew in January 1941. This was the first prototype with the large, 10.506 m (34 ft 5½ in) wing with an area of 18.3 m² (196.979 sq ft). This wing was standard through to the A-5 (the A-3 introduced modified ailerons).

 

The A-6 wing was redesigned and strengthened internally to carry the MG 151/20 on the outer gun bays, otherwise the span and area remained the same; this wing was used for all subsequent As and the D-9.

Edited October 9, 2016 by NZTyphoon

[Bert_Foster]

Trouble is so many other references list the A6 as the start of the 34'51/1in wing.... like FW190 by Gordon Swanborughand William Green Pg43 ..... "This new wing with a slightly increased of span became a production feature effective with the fw190-A6 subseries but was first flown on the two A5-U9's and two A-5/U10's ".

 

Though I reckon if you had to pick one refrence Then Smith&Creek would be it.

Edited October 9, 2016 by Bert_Foster

[Crump]

 

 

Nit picking I know but A0-A5 had wingspan 10.393m A6 -D9 had wingspan 10.506m

 

Airplanes were still built on jigs one aircraft at a time.  There is some variations.  By Focke Wulf Specification, the wingspan is 10.5m for in all the Antons and the Dora 9. 

[MiloMorai]

Almost 4.5" difference. That be some variation.

 

You better contact Dietmar Hermann and tell him his wing span for the A-1 is wrong.

[Crump]

 

 

Almost 4.5" difference. That be some variation.

 

Not really and it also depends on what you pick as the measuring point.  It is not uncommon to find some minor variation in aircraft. 

[JtD]

Smith & Creek pretty much quote the canon, that's what you can find in about every book that deals with the early Fw190. However, Fw in the manuals insists that the A-1 was different from later versions. I would have liked to see this commented on in some book.

[MiloMorai]

Not really and it also depends on what you pick as the measuring point.  It is not uncommon to find some minor variation in aircraft. 

 

Oh please. Wingspan is the straight line distance from wing tip to wing tip.

 

~4.5" is a minor variation.

[Crump]

Edited October 9, 2016 by Crump

[ZachariasX]

Oh please. Wingspan is the straight line distance from wing tip to wing tip.

 

~4.5" is a minor variation.

Do blueprints exist for wings featuring these differences in wingspan?

 

If not, I'd seriously doubt some of the measurements that end up being repeatedly quoted. You have different assembly lines in different factories and they have their own way of doing things. People make errors all the time. Not just us forum lurkers. Even "hard data" is produced by people within a certain context. Question the scource as much as yourself.

 

Different factories using different jigs to produce aircraft will inevitably produce some variations. Not all variations are equally bad, especially as long as the aircraft still fits together. IIRC for instance with the Yaks of the same series, wings couldn't be interchanged as they were made "fit" eventually for the very airframe they was produced with. Factory tolerances between the aircat were too large.

 

So, I'd really be interessted in seeing blueprints for both wingspans. If they don't exist... There's a reason why the "Oh please..." often enough turns into "You had ONE job...!"