FW190 vs. BF109: Turn Radius (2011)

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It's a conspiracy I tell you, a conspiracy!

(Image removed from quote.)

Viewing this on my phone just noticed the logo 

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Do we really have to produce the sustained turn equation again? It's a function of the wingloading and, implicitly, both the powerloading (via max bank) and the slope of the CL/CD curve (via the CL at the sustained turn).

In any case, it's hard to tell what you're arguing here, Perv, since it's a fact that the turn rate of the Spit, as well as its radius, are both much better than that of the 190.

Otherwise and with regard to this thread, Holy Necro-Bump Batman!!!

So if both aircraft are turning at 360 mph constant then which aircraft has the smaller turn radius?

Are you saying that under the circumstances I have described the fw190d has not got enough thrust to sustain a turn at a more or less constant speed?

[Stoney]

Lets hear why. 

Because in aerodynamics, there are only two figures of merit that are used to classify turning maneuvers--radius and rate.  The FW-190 cannot match the Spitfire in either, especially in sustained turns, but even if instantaneous turning is considered.

[Stoney]

So if both aircraft are turning at 360 mph constant then which aircraft has the smaller turn radius?

Are you saying that under the circumstances I have described the fw190d has not got enough thrust to sustain a turn at a more or less constant speed?

Neither of these aircraft can produce enough thrust to maintain a 360 mph IAS sustained turn.

[Charge]

"Do we really have to produce the sustained turn equation again? It's a function of the wingloading and, implicitly, both the powerloading (via max bank) and the slope of the CL/CD curve (via the CL at the sustained turn)."

Still after years of reading these boards it escapes me how the relative turn performance can be determined accurately only with wing-loading as input for aerodynamic quality. No max AoA taken into account, no max lift, high lift devices, what else?

If the common equation used for this gives the definite answer then IRL a huge, very thin flat plate with 1:1 aspect ratio would be turning better than, say, 6:1 aspect long wing with half the area and a good wing profile. Wouldn't it? IF it doesn't, would it be safe to say that the equation gives an approximation, nothing more, and it is up to the user to interpret how closely two planes can be compared in the first place using that equation?

-C+

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Neither of these aircraft can produce enough thrust to maintain a 360 mph IAS sustained turn.

If I can get on tonight after work I will knock up a film 

[FLS]

I found a russian site about the fw190a8 tactics on the eastern front , I was most surprised that according to these russian resources Fw190a8 could outrun / give too slow catchup to prevent guns use.

http://www.airpages.ru/eng/lw/fw190a7.shtml

If you compare that to what Fw190a8 represents in AH , its slower / much slower at the deck, but  RL speed gave  the 190a8 survivability in many cases

According to the site you linked the AH FW190A8 max speed is correct. The inability to catch them was due to the response time not the aircraft speed. Keep in mind that ground level is not necessarily sea level and temperature affects air density and speed.

[PJ_Godzilla]

"Do we really have to produce the sustained turn equation again? It's a function of the wingloading and, implicitly, both the powerloading (via max bank) and the slope of the CL/CD curve (via the CL at the sustained turn)."

Still after years of reading these boards it escapes me how the relative turn performance can be determined accurately only with wing-loading as input for aerodynamic quality. No max AoA taken into account, no max lift, high lift devices, what else?

If the common equation used for this gives the definite answer then IRL a huge, very thin flat plate with 1:1 aspect ratio would be turning better than, say, 6:1 aspect long wing with half the area and a good wing profile. Wouldn't it? IF it doesn't, would it be safe to say that the equation gives an approximation, nothing more, and it is up to the user to interpret how closely two planes can be compared in the first place using that equation?

-C+

It's a linear range equation so, no, the max AoA isn't taken into account. The impact of high lift devices is taken into account via the Cl curve itself. As for your assertion about the aspect ratio, I'd say it's incorrect, given that the slope of the CL vs Cd curve is ideally high and a low AR is going to allow the induced drag to be high. As for the flat plate, maybe, depending on how it's linear range CL vs CD performance compares to a good airfoil (I doubt favorably).
The following is from another post of mine...
Recall that Cl appears in the denom of that sustained turn equation. It'll be the Cl that delivers enough lift at some extreme bank theta max such that you lose no alt. This is where relative drag plays in to making or breaking the fighter. You can express, of course, the Cl as a function of the Cd0 and Cd, right? I.e., Cl = ((Cd-Cd0)/k)^.5. and THAT's ASSUMING WE'RE IN THE LINEAR CD VS CL REGION...

Since sustained turn will go up as Cl required decreases, we want to minimize (Cd-Cd0)/k
Remember that k = 1/(pi*AR*e) so that the denom will grow with AR. Leaving that aside since intuitively pleasing anyway, we can go on. Since Cd0 is a constant and Cd is always going to be greater than Cd0 at positive lift, we can say we want minimal induced drag for the necessary lift, yes? And this is why a Spitfire makes a better fighter than a barn door if both have the same wingloading and powerloading.   I.e. you want something with a very healthy d(Cl)/d(Cd) as well as the two aforementioned attributes.

[Karnak]

If I can get on tonight after work I will knock up a film 

Once again, you're not testing any turn here.  You're testing speed.

What you are claiming is the same as a P-51 fan claiming the P-51 will climb faster than a Spitfire and then setting the climb speed to 350mph, knowing full well the Spitfire can't climb at that speed.  I mean, who cares that the P-51's best climb is ~3400fpm and the Spitfire's best is ~4500fpm if you you can write the test to have a predetermined outcome by changing the "climb" test into a "speed" test.  That is what you are doing here.  You are changing a "turn" test, which the Fw190 has no chance of being equal to the Spitfire in, to a "speed" test and just calling it a turning test.

[PJ_Godzilla]

Or, he's looking at the right hand side of the E-M and talking turn rate at a specific speed... a slightly different idea but one with some merit. Whether or not he's savvy to the E-M, I don't know.

[Stoney]

Or, he's looking at the right hand side of the E-M and talking turn rate at a specific speed... a slightly different idea but one with some merit. Whether or not he's savvy to the E-M, I don't know.

I think what Charge was trying to say is what I've started saying over and over again now.  Excess power available is what allows a Spit or any other aircraft to out turn any other aircraft.  Doesn't matter about wing load, power load, or any of those other figures of merit.  Even an aircraft that's capable of an extreme Clmax can't do anything with it unless it has the power to do so.

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Here you go, one big giant turn in a FW190-D sustained at never below 370 mph. ps best up the viewer speed to x2 

** NOTE ONLY USE FIREFOX BROWSER TO OPEN THIS LINK **
http://www.4shared.com/file/Za-lQ9Ep/370_turn.html
** NOTE ONLY USE FIREFOX BROWSER TO OPEN THIS LINK **

Neither of these aircraft can produce enough thrust to maintain a 360 mph IAS sustained turn.

How can this be true if I can turn at 370-380 mph?? You can dress it up how you like but it is still a flat turn sustained at over 360 mph.

[FLS]

Are you confusing IAS and TAS? The FW190D only goes slightly more than 360 IAS with WEP in a straight line.

[Karnak]

Are you confusing IAS and TAS? The FW190D only goes slightly more than 360 IAS with WEP in a straight line.

No, he isn't.  He is playing BS semantic games.

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No, he isn't.  He is playing BS semantic games.

Your nerd rage amuses me, the original statement of fact was simply a cheeky wee comment but true none the less. Your taking this quite badly I see