Moderators please lock this thread.

[JG13_opcode]

It was a good experiment in trying to get people to just get along amicably but nope.

 

Moderators, please lock or delete.

Edited October 14, 2016 by JG13_opcode

[II./JG77_Manu*]

For starters, we don't have to test everything in game. Han gave us already the CLmax the 190 uses in game, we only have to compare it to RL sources (which we already did partly)

Edited September 28, 2016 by II./JG77_Manu*

[JG13_opcode]

For starters, we don't have to test everything in game. Han gave us already the CLmax the 190 uses in game, we only have to compare it to RL sources (which we already did partly)

 

......... oh.

 

I skimmed or misread that, I guess.  I thought he was just commenting on the tunnel.

 

 

I guess a different approach is needed, then.

[Livai]

For starters, we don't have to test everything in game. Han gave us already the CLmax the 190 uses in game, we only have to compare it to RL sources (which we already did partly)

 

Don't tell me they use just one CLmax for the whole plane? A 190 with combat flaps or full flaps has a much different CLmax. The CLmax increase if you use flaps!

[Dakpilot]

Great idea, preferably presented by some persons without an accusatory history of bias of Dev's, bans and general mutual ill feeling, put forward politely in the requested format

 

much more likely to gain traction, in most recent Q and A Han said FM changes are possible with good info communicated correctly (as has always been the case)

 

Cheers Dakpilot

[=EXPEND=13SchwarzeHand]

I am currently gathering original data in order to prove our point. So besides doing the testing in flight, we need to consider which data we currently have in order to back up our argumentation. The devs told us that they base their information on the 6006 chalais meudon report. I think I will be able to acquire it in the next days. Then we have a basis for discussion.

 

 

Edit: the report is not just the chart that has been shown time and again but actually a 150 page full scale report

Edited September 28, 2016 by II/JG17_SchwarzeDreizehn

[=EXPEND=13SchwarzeHand]

If you said you sent a report would you mind sharing it?

[JG13_opcode]

 

 

Great idea, preferably presented by some persons without an accusatory history of bias of Dev's, bans and general mutual ill feeling, put forward politely in the requested format

 

 

I have a tendency to be negative but I've never accused them of bias or incompetence.

I am currently gathering original data in order to prove our point. So besides doing the testing in flight, we need to consider which data we currently have in order to back up our argumentation. The devs told us that they base their information on the 6006 chalais meudon report. I think I will be able to acquire it in the next days. Then we have a basis for discussion.


Edit: the report is not just the chart that has been shown time and again but actually a 150 page full scale report

 

Awesome.

[JG13_opcode]

Please, you guys who know what you are talking about, put together a calm, factual case with all the details (not just a chart) in the format that they are looking for, PM it to Han and post it in the FM section (not for debate but so that everyone knows exactly what was actually submitted). Then post the devs' response when it comes back.

 

This is exactly my plan.

[E69_geramos109]

Nice. Lets see if this post has future. 

Luck and thanks.

Edited September 28, 2016 by E69_geramos109

[JG13_opcode]

I am currently gathering original data in order to prove our point. So besides doing the testing in flight, we need to consider which data we currently have in order to back up our argumentation. The devs told us that they base their information on the 6006 chalais meudon report. I think I will be able to acquire it in the next days. Then we have a basis for discussion.

 

 

Edit: the report is not just the chart that has been shown time and again but actually a 150 page full scale report

I'll hook you up with some webspace if you need to upload it somewhere.

[=EXPEND=13SchwarzeHand]

Thanks a lot opcode.

The current situation however is that the document has copy right restrictions. Additionally it is watermarked an traceable to me so I am basically fucked when I upload it entirely. Please also be aware that it is entirely in German.

I am sure that there will be a way to share information though. First we have to scan it for relevant information, which I (or JTD if he wants to) will post on this thread.

If there are still questions remaining you can PM me and again I'm sure there will be a way to share any relevant info bilaterally.

And I totally agree that we should have some sort of a coordinated claim, because 20 people going to the devs with 20 half finished reports won't help us.

Let's keep fingers crossed!

Edited September 28, 2016 by II/JG17_SchwarzeDreizehn

[JtD]

I've already started a new conversation with the devs a couple of days ago. There appeared to be a more open, less hostile attitude in the latest developer statements, so I thought I'd try.

[Asgar]

If you need more eyes to scan through the document let me know and I help you

[Irgendjemand]

I cannot contribute too much but i wanted to tell you guys:

 

THANKS FOR YOUR EFFORT! I press my thumbs this will finally lead to some changes.

[II/JG11_ATLAN_VR]

I hope this helps but mainly FW190A5 but this the upcoming plane for BOK and not quite different to the A3!

 

http://www.wwiiaircraftperformance.org/fw190/fw190a5.html

[Dr_Molem]

Makes me wonder where Kurt Tank went wrong creating a manuverable aircraft.......................?

 

... 

[Luger1969]

Guys you have my support. I think there is a opportunity here, there is good ideas and spirit in this thread already. Thank you very much for the effort. 

[URUAker]

Thank you! great idea! Just a few days ago Han posted this on the question for developers thread:

 

As I've said many times before, rule is: in my PM box should be a message where will be:

1. Claim detailed decription, which explain all aspects of the claim

2. Supporting historical technical sources like flight manuals, flight test reports and so on, with strict pointing page and line where we should look for proofs

3. Strict flight tests in game, which shows significant difference between game and historical source.

If it is - we start to investigate the claim. Two finals are possible:

1. We provide "our FM is ok" proofs

2. We fix the issue

I'm hope it's clear. And, actualy, it works.

 

I share the feelings of many that there is something to fix with the way the FW behaves, but for me is just a feeling, I don´t know anything about aerodinamics and have no proof. And i´m open to be proven wrong.

 

But there are ppl that seams to know what they talk about but the way they conduct themselves makes me question their intentions and partiality. In the other thread I asked them to share their reports and responses from the Devs but noone will do, so either they didn´t report anything, or they got a response they are not willing to make public.

 

If we could make a report put together by the communitty it will be great!

[LuftManu]

I support this! Please, don`t turn this into a graveyard! Only post things to add, if you don`t think the FM of the FW190 should be revised just stay away from the thread, the Devs will make the last turn.

[Wulf]

Well I wish the endeavour every success but I won't be wagering cash on the chances of a positive outcome.   The simple truth is, you don't have to be a rocket scientist to know the current 190 exhibits very poor flight characteristics.  Five minutes in the thing will tell you that.   Why that didn't set off alarm bells when the new FM was tested I just don't understand.

 

As for the argument that the soon to be released A-5 will be a better aircraft, because it incorporates an entirely co-incidental change to the CoG; frankly, I have not seen any historical material, anywhere, that  would suggest the handling characteristics of the A-5, or for that matter the  A-6/A-7 or A-8 were better than the A-3.   In fact, quite the opposite.  And as for the D-9, as far as I know, while possessing much better high altitude performance, it would not have been a match for an A-3 in terms of agility.

[Livai]

I am not sure if the Devs take in account if they operating with wind tunnel data. As well as German-French WT test. That the flight tests always shows lower CLmax because of trim losses! I mean stabiliser negative lift that is very sufficient at high trimmed CL's!

[Livai]

Found something to calculate with

 

Clean Stall: 118 IAS = 190 km/h -> taken from http://www.wwiiaircraftperformance.o...-47-1658-D.pdf

Wing area : 196,98 ft^2 -> taken from internet

Weight (max. take off): 9667,27 lbs = 4385kg -> taken from this game

 

Vso = sqrt(9667 * 2/(0.002377*1.38*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,38

 

I am a little confused about the in-game spec about the weight? Is the 4385kg the max weight with both MGFF with 90 rounds and fuel tank with 524 litres, because other source say something about maximum 3,978 kg (8,770 lbs) weight? I think the 3,978 kg (8,770 lbs) mean the Focke without outer MGFF cannons or maybe not?

 

This source say a Fw-190 A-3 with all wing cannons has 3978 kg (8770 lbs) https://books.google.de/books?id=wm_YDAAAQBAJ&pg=PA36&lpg=PA36&dq=fw+190+a-3+8770+lb&source=bl&ots=wsBP5RcMQ6&sig=ONTeU84SGyuiEKeGuQmDWTYRJPE&hl=de&sa=X&ved=0ahUKEwj23rfB5bbPAhXIXiwKHZG3D80Q6AEIVTAJ#v=onepage&q=fw%20190%20a-3%208770%20lb&f=false

 

Vso = sqrt(8770 * 2/(0.002377*1.25*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,25

 

Other source say about 4100 kg (9039 lbs) same weight that a Fw 190 A-6 has with all wing cannons http://www.wwiiaircraftperformance.org/fw190a/190a5-performancetable.jpg

 

Vso = sqrt(9039 * 2/(0.002377*1.29*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,29

 

My probability calculation of the CLmax value is between 1,25 ~ 1,38. However I think we can forget the 1,38 value because I think the in-game weight is maybe wrong 4385kg (9667 lbs) with all wing cannons. The Fw-190 A-6 weight with 4x MG151 wing cannons is 4100 kg (9039 lbs) so a Fw-190 A-3 with 2x MG151 + 2x MGFF wing cannons will weight a little less or between 3978 kg (8770 lbs) and 4100 kg (9039 lbs).

 

Short said we are talking about a CLmax from 1,25 to 1,29 for a clean stall at 118 IAS.

Edited September 30, 2016 by Superghostboy

[II./JG77_Manu*]

Yo-Yo, a developer of Eagle Dynamics Fw190 explains here, how they found the Clmax for the 190:

 

https://forums.eagle.ru/showpost.php?p=2910954&postcount=2

 

Should be the same for our 190 here. 

[LuftManu]

Yo-Yo, a developer of Eagle Dynamics Fw190 explains here, how they found the Clmax for the 190:

 

https://forums.eagle.ru/showpost.php?p=2910954&postcount=2

 

Should be the same for our 190 here. 

That is an interesting read for the Devs, maybe they can also implement those things to get this FM more accurate.

[=EXPEND=13SchwarzeHand]

Yo-Yo, a developer of Eagle Dynamics Fw190 explains here, how they found the Clmax for the 190:   https://forums.eagle...954&postcount=2   Should be the same for our 190 here. 

 

 

I can confirm from the Reynolds number stated in your link and support it with original data. As it has been already stated, the Reynold´s number is 4.6*10^6.

This is lower than the lowest IAS in flight. I suppose this will be new information for the devs.

 

 

 

The test additionally states that the wing is frequently covered in insects. The inlet of the wind tunnel is actually right behind some trees, which might cause further pollutions. From Photographs you can see that the FW is actually covered in paint and that there are holes etc. for the gun ports, which have been left open in order to fixate the plane.

 

 

 

 

These might seem like small things, however. if you compare it to some studies that have been made regarding "roughness" of wings and the subsequent adjustments to the clmax you see that these might actually substantially influence the outcome of measurements.  

(https://www3.nd.edu/~ame40462/RiegelsAerofoilSections.pdf see p. 50)

 

 

As a result if other AC are not also adjusted for these imperfections accordingly, there might be a big discrepancy between the measured values of CM and other values (in addition to the already low Reynold´s number).

 

 

A discussion with the Devs is underway and as I hear, there seems to be a more open attitude towards criticism of the current FM. I am not part of the discussion but I will try to keep you updated as far as I can!

Edited September 30, 2016 by II/JG17_SchwarzeDreizehn

[II./JG77_Manu*]

 

 

A discussion with the Devs is underway and as I hear, there seems to be a more open attitude towards criticism of the current FM. I am not part of the discussion but I will try to keep you updated as far as I can!

Very glad to hear. Thanks 

[Holtzauge]

Found something to calculate with

 

Clean Stall: 118 IAS = 190 km/h -> taken from http://www.wwiiaircraftperformance.o...-47-1658-D.pdf

Wing area : 196,98 ft^2 -> taken from internet

Weight (max. take off): 9667,27 lbs = 4385kg -> taken from this game

 

Vso = sqrt(9667 * 2/(0.002377*1.38*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,38

 

I am a little confused about the in-game spec about the weight? Is the 4385kg the max weight with both MGFF with 90 rounds and fuel tank with 524 litres, because other source say something about maximum 3,978 kg (8,770 lbs) weight? I think the 3,978 kg (8,770 lbs) mean the Focke without outer MGFF cannons or maybe not?

 

This source say a Fw-190 A-3 with all wing cannons has 3978 kg (8770 lbs) https://books.google.de/books?id=wm_YDAAAQBAJ&pg=PA36&lpg=PA36&dq=fw+190+a-3+8770+lb&source=bl&ots=wsBP5RcMQ6&sig=ONTeU84SGyuiEKeGuQmDWTYRJPE&hl=de&sa=X&ved=0ahUKEwj23rfB5bbPAhXIXiwKHZG3D80Q6AEIVTAJ#v=onepage&q=fw%20190%20a-3%208770%20lb&f=false

 

Vso = sqrt(8770 * 2/(0.002377*1.25*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,25

 

Other source say about 4100 kg (9039 lbs) same weight that a Fw 190 A-6 has with all wing cannons http://www.wwiiaircraftperformance.org/fw190a/190a5-performancetable.jpg

 

Vso = sqrt(9039 * 2/(0.002377*1.29*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,29

 

My probability calculation of the CLmax value is between 1,25 ~ 1,38. However I think we can forget the 1,38 value because I think the in-game weight is maybe wrong 4385kg (9667 lbs) with all wing cannons. The Fw-190 A-6 weight with 4x MG151 wing cannons is 4100 kg (9039 lbs) so a Fw-190 A-3 with 2x MG151 + 2x MGFF wing cannons will weight a little less or between 3978 kg (8770 lbs) and 4100 kg (9039 lbs).

 

Short said we are talking about a CLmax from 1,25 to 1,29 for a clean stall at 118 IAS.

 

Ok, this is good in the sense that it shows how you can calculate a Clmax so thanks for posting it. However, Clmax is very dependant on how much power the engine is producing, as an example the Spitfire Clmax power off is around 1.36 and with power on can be as high as 1.9. Secondly, the calculation will be dependent on the assumed IAS and this can be difficult to pin down accurately and unless it can be determined that the source has corrected for instrumented and position error it is questionable as evidence.

 

A good example is the Spitfire Clmax: You will find people claiming this was as low as 1.2 based on a NACA report. However, the RAE refuted that and pointed out the relatively crude method used to determine the speed used in the NACA trial (Accompanying aircraft IIRC). Anyway, the RAE did their own testing using something called a trailing pitot which is a IAS measuring device which is very accurate since the pitot and the static orifices are trailed far behind and below the aircraft essentially eliminating position errors. Using that method they determined the power off Clmax for the Spitfire to 1.36 and they also arrived at the same Clmax for the Me-109 as the Germans:namely 1.4.

 

So even when reading reports from pros like NACA, that does not guarantee that everything in the report can be used without scrutiny. So ideally what we are looking for is report with a flight trial measurement of a representative Fw-190 with idling engine with the IAS determined using a trailing pitot system. Since the Brits did this on both the Spitfire and Me-109 and had a captured Fw-190 at their disposal they may have done such a trial. Unfortunately I have never heard about it but in this case it would be the Holy Grail we are looking for.

I can confirm from the Reynolds number stated in your link and support it with original data. As it has been already stated, the Reynold´s number is 4.6*10^6.

This is lower than the lowest IAS in flight. I suppose this will be new information for the devs.

 

CM.png

 

 

The test additionally states that the wing is frequently covered in insects. The inlet of the wind tunnel is actually right behind some trees, which might cause further pollutions. From Photographs you can see that the FW is actually covered in paint and that there are holes etc. for the gun ports, which have been left open in order to fixate the plane.

 

 

 

FWCM.png

 

These might seem like small things, however. if you compare it to some studies that have been made regarding "roughness" of wings and the subsequent adjustments to the clmax you see that these might actually substantially influence the outcome of measurements.  

(https://www3.nd.edu/~ame40462/RiegelsAerofoilSections.pdf see p. 50)

 

 

As a result if other AC are not also adjusted for these imperfections accordingly, there might be a big discrepancy between the measured values of CM and other values (in addition to the already low Reynold´s number).

 

 

A discussion with the Devs is underway and as I hear, there seems to be a more open attitude towards criticism of the current FM. I am not part of the discussion but I will try to keep you updated as far as I can!

 

Great! Keep it coming!

[Art]

 

 

A discussion with the Devs is underway and as I hear, there seems to be a more open attitude towards criticism of the current FM. I am not part of the discussion but I will try to keep you updated as far as I can!

Last hope! 

[6./ZG26_Klaus_Mann]

Just voicing my support for you guys. Any way this game gets more realistic, the better. 

 

I will at some point try and make a complete acceleration chart for all fighters, will take some time though. 

Edited September 30, 2016 by 6./ZG26_Klaus__Mann

[Holtzauge]

I can confirm from the Reynolds number stated in your link and support it with original data. As it has been already stated, the Reynold´s number is 4.6*10^6.

This is lower than the lowest IAS in flight. I suppose this will be new information for the devs.

 

CM.png

 

 

The test additionally states that the wing is frequently covered in insects. The inlet of the wind tunnel is actually right behind some trees, which might cause further pollutions. From Photographs you can see that the FW is actually covered in paint and that there are holes etc. for the gun ports, which have been left open in order to fixate the plane.

 

 

 

FWCM.png

 

These might seem like small things, however. if you compare it to some studies that have been made regarding "roughness" of wings and the subsequent adjustments to the clmax you see that these might actually substantially influence the outcome of measurements.  

(https://www3.nd.edu/~ame40462/RiegelsAerofoilSections.pdf see p. 50)

 

 

As a result if other AC are not also adjusted for these imperfections accordingly, there might be a big discrepancy between the measured values of CM and other values (in addition to the already low Reynold´s number).

 

 

A discussion with the Devs is underway and as I hear, there seems to be a more open attitude towards criticism of the current FM. I am not part of the discussion but I will try to keep you updated as far as I can!

 

Had a quick look in the report and found this in the conclusions on page 12 (My non-professional translation so it may not be a 100%):

 

“Without flaps the Camax =1.3 and with 58 deg flaps 1.55. The values are 0.3 to 0.4 below those for smooth models. The difference is due to the effects of fuselage, supports, open joints and deviations in the wing profile.”

 

So it looks like the Clmax should at least be 1.3 for the real aircraft at Re=4.6 M making the Clmax=1.35-1.38 at higher Re previously mentioned by Kwiatek quite plausible. In addition when comparing to Russian and NACA wind tunnel model trials of similar designs, it looks like FW had wind tunnel results ranging from 1.6 to 1.7  which is quite good. So if this holds then it looks like the Fw-190 is actually pretty good in this department after all.

 

Of course this is just preliminary input based on a quick read but it sure looks promising......

[Wulf]

Found something to calculate with

 

Clean Stall: 118 IAS = 190 km/h -> taken from http://www.wwiiaircraftperformance.o...-47-1658-D.pdf

Wing area : 196,98 ft^2 -> taken from internet

Weight (max. take off): 9667,27 lbs = 4385kg -> taken from this game

 

Vso = sqrt(9667 * 2/(0.002377*1.38*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,38

 

I am a little confused about the in-game spec about the weight? Is the 4385kg the max weight with both MGFF with 90 rounds and fuel tank with 524 litres, because other source say something about maximum 3,978 kg (8,770 lbs) weight? I think the 3,978 kg (8,770 lbs) mean the Focke without outer MGFF cannons or maybe not?

 

This source say a Fw-190 A-3 with all wing cannons has 3978 kg (8770 lbs) https://books.google.de/books?id=wm_YDAAAQBAJ&pg=PA36&lpg=PA36&dq=fw+190+a-3+8770+lb&source=bl&ots=wsBP5RcMQ6&sig=ONTeU84SGyuiEKeGuQmDWTYRJPE&hl=de&sa=X&ved=0ahUKEwj23rfB5bbPAhXIXiwKHZG3D80Q6AEIVTAJ#v=onepage&q=fw%20190%20a-3%208770%20lb&f=false

 

Vso = sqrt(8770 * 2/(0.002377*1.25*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,25

 

Other source say about 4100 kg (9039 lbs) same weight that a Fw 190 A-6 has with all wing cannons http://www.wwiiaircraftperformance.org/fw190a/190a5-performancetable.jpg

 

Vso = sqrt(9039 * 2/(0.002377*1.29*197) = 173ft/sec = 190 km/h = 118 IAS

 

The CLmax is here = 1,29

 

My probability calculation of the CLmax value is between 1,25 ~ 1,38. However I think we can forget the 1,38 value because I think the in-game weight is maybe wrong 4385kg (9667 lbs) with all wing cannons. The Fw-190 A-6 weight with 4x MG151 wing cannons is 4100 kg (9039 lbs) so a Fw-190 A-3 with 2x MG151 + 2x MGFF wing cannons will weight a little less or between 3978 kg (8770 lbs) and 4100 kg (9039 lbs).

 

Short said we are talking about a CLmax from 1,25 to 1,29 for a clean stall at 118 IAS.

 

 

I suspect (but don't know for a fact ) that the A-6 would have been the heavier of the two.  As you'd be aware, the A-6 introduced a new lighter/strengthened and somewhat bigger wing (just how much lighter I haven't been able to establish) but it also featured heavier (Kgs) weapons, an increased ammunition load, plus in some forms,  increased armour.  If we knew what weight savings were achieved with the new wing matters would be much easier.  However,  we do know that each of the two new MG 151s would add 16 kgs, plus ammo, maybe another 10+ kgs per gun + depending on which version of the A-6 we're talking about another 10 + kgs of armour.  So, for the A-6 to weigh the same as the A-3 I suspect the new wing would have had to have been about 60-80 kgs lighter than the A-3 wing.  Whether it was or not I don't know.  If someone does it would be interesting to find out.

Edited September 30, 2016 by Wulf

[216th_Lucas_From_Hell]

Very nice initiative. The more objective we make the game the better, and this is just the type of community-developer relationship we need. Good luck

[IVJG4-Knight]

I've see mentioned a couple of times other simulations that offer a 190 flying plane and my opinion is the the A3 FM is BOS is a more accurate representation of the high speed handling characteristics.Which are impressive.When and if an Il2 version D9 becomes available it would be scary good at high speed.

At low speed  i've seen a few weird things like no rudder authority in some situations on both 190 and 109.Also i think that if the FW a5 that will be produced for Battle of Kuban will have harsher stall characteristics that  would be too much.No aircraft manufacturer would produce an aircraft that stalls faster than this A3.

Edited October 1, 2016 by IVJG4-Knight

[Bert_Foster]

 

From this source document:

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0001924000049629

[=EXPEND=13SchwarzeHand]

These are the theoretical clmax values, from a simulation of a 190 D IIRC. No historical document or actual measurement though. Although this definitely does give an imdication of the direction the values should be adjusted to.

[Holtzauge]

Yes, the text in Lednicers report even says its based on 2D Clmax figures for the profile and we already know the NACA230- series profile that the Fw-190 used it quite good in this department. Anyway it's good that we now thanks to you SchwarxDreizehn have a more representative 3D full scale Clmax figure of 1.3 at Re=4.6 M (See attached figure for "Leerlauf"=idling engine) meaning the IRL Clmax at a stall at Re=6.4 M would probably be significantly higher, maybe in the order of 1.35 to 1.4.

Edited October 1, 2016 by Holtzauge

[JG13_opcode]

My German needs work. Mein Gott.

[6./ZG26_5tuka]

 

With prop at idle a camax of 1.3 resulted without flap extension, with flaps in landing position (betak=58°) to 1.55. The values are 0.3 to 0.4 lower than the values for the smooth profile. This difference is caused by the fuselage, metal bumps*, gaps and variantion of the exact profile form.

* unsure if that's the right word

Edited October 1, 2016 by 6./ZG26_5tuka

[Crump]

Yes, the text in Lednicers report even says its based on 2D Clmax figures for the profile and we already know the NACA230- series profile that the Fw-190 used it quite good in this department. Anyway it's good that we now thanks to you SchwarxDreizehn have a more representative 3D full scale Clmax figure of 1.3 at Re=4.6 M (See attached figure for "Leerlauf"=idling engine) meaning the IRL Clmax at a stall at Re=6.4 M would probably be significantly higher, maybe in the order of 1.35 to 1.4.

 

 

That is because David Lednicer is an educated aeronautical engineer and he is correct to use the 2D data if he wants to determine what the aircraft will do.

 

The foundation of aeronautical engineering is the fact that our airfoil 2D data must agree with our Three dimensional wing.

 

 

 

It is how the physical world works.

 

The polars from Chalais-Meudon agree with the NACA airfoil data under the same conditions.