Slats deploying at high speed ?

[Ala13_ManOWar]

re-quote myself

And re-quote the trimmed version of the text. Somebody posted full version and flips over the pilot is talking about 1939-early 40 before "new Spitfires" arrived... And you want that to be the perfect fit for a K4...

 

 

So according to that quote, you could get a different answer which turned better, depending on the pilot.

So exactly what we have now in DCS, so that means DCS is perfect as is now?

 

 

The thing is straight unsloted wing will stall first in wingtips, so slats provide better control of the stall keeping ailerons useful. That means... what means? Means you want K4 to turn like a a6m2 because a bit slot aid? Or what? I don't really get were is the problem people is claiming for. I mean, DCS model can be fine or mistaken, but what's the test you people performed and what have you see in that test to claim what? If you understand me, I want to understand it and may be perform my own tests to see what are you claiming because if we are having a nice friends talking about slats it's fine but if it's a simulator claim I don't know what's the claim now and based on what, serious.

 

S!

Edited May 8, 2015 by Ala13_ManOWar

[Solty]

I think this whole problem comes from the underestimated ability of the P-51D to turn by Otto.

 

P-51D is not a good turner to be compared to Spitfire or Yak or even Bf109F... but Bf109G and K sacrificed their ability to turn for better energy retention in vertical maneuvering. (Zero is another whole class of turner compared to all those planes)

 

P-51D is not even better turner than Bf109K4 though. I have flown quite a few sorties and I can tell you that it depends on the load that the plane has. If the P-51D takes 68% fuel (standard) it will not be able to match the 109K4 with 100% of fuel. With 100% fuel the P-51 is even worse.

 

Times at which I was able to outturn the 109 were when I used 35% on takeoff which means I had around 30% or less when the fight began.

 

I can't stress how much difference is between 30% and 70% of fuel for the P-51D which was able of 7h missions while Bf109K would be around 1:30h missions capable (both with external fuel).

 

I can't understand why all 109 pilots want to turn. Learn some ACM and get used to your way more powerful advantages like ROC and acceleration and add to that your turning ability (which is still better than P-51's even if not by much)

 

I don't understand why people want to put '=' between E4 and K4

Bf109E4≠Me109K4.

Edited May 8, 2015 by Solty

[Hummingbird]

What you see here (below) is that the slats increase the critical AoA, and therefore CLmax, in the outboard wing section to match that of the inboard section. This is in contrast to washout which just decreases the AoA of the outboard section to keep it from stalling first, thus no extra lift is gained. With the slats you get the benefit of full lift right up to the point where the inboard section stalls, which means an increase in the overall CLmax usually of around 15-20%, which is significant.

 

 

Messerschmitt tried all types of methods to increase the overall lift of the wing to compensate for the small wing area (which was that small to decrease drag), and the outboard mounted slats was by far the best solution of them all. Full span automatic slats wasn't an option because of the strong prop stream present on fighters with their powerful engines, but this extra power also made it redundant as the inner section would always stall last while generating a lot more lift when energized by the prop stream.

Edited May 9, 2015 by Hummingbird

[GrapeJam]

15%-20 is significant, yeah. All and all it's nowhere near the uber thing you're trying to hype it out to be. And I'm interested it the formula that made you got that 15-20% number out of it, hopefully it's not something out of your optimistic "SWAG".

Edited May 9, 2015 by GrapeJam

[9.JG27 DavidRed]

If the P-51D takes 68% fuel (standard) it will not be able to match the 109K4 with 100% of fuel

 

 

that is not true though. ive seen it myself quite often, and also tried it myself against solid pilots, and the P51 is able to keep up and even outturn the 109 with fuel loads up to 68%.(and i am quite out of training in the P51) i never change my fuel-loads in the P51(im just too lazy for it) and for sure, the P51 can turn with the 109...

 

actually their turning performance are just about equal i would say.yes, fuel load can help, it matters whether its a right or a left hand turn.at certain speeds p51 will turn better, and at certain speeds 109 will turn better...

its a very close match between the two, and assuming you have two similar pilots, the one with inital advantage will outturn the other.

 

 

what im interested in though is, why the P51 flaps do help by such a margin in sustained turns, while there is no gain whatsoever in the 109 when using them...

[Solty]

I was talking sustained turn. Yes at instantenaus turn at high speed the P51 is better, but sustained is a whole other story.

 

I performed a series of turn fights against a friend that has similar experience. I am a bit better with 109 and he is better in 51. We were both capable of out turning the P51 when we flew with standard loads. Only when weights of both planes were equal, the 109 lost its advantage.

 

Without flaps 51 is quite unstable in turns.

 

With flaps and standard loads 109 still had advantage but it was riding the edge and it could take 6 full turns to out turn the P51.

 

I don't like to turn. Rock&Roll is my way for defense. If turn performance was so important we would still fly biplanes. B&Z all day.

[[DBS]TH0R]

What you see here (below) is that the slats increase the critical AoA, and therefore CLmax, in the outboard wing section to match that of the inboard section. This is in contrast to washout which just decreases the AoA of the outboard section to keep it from stalling first, thus no extra lift is gained. With the slats you get the benefit of full lift right up to the point where the inboard section stalls, which means an increase in the overall CLmax usually of around 15-20%, which is significant.

 

Is that your interpretation or what says in the document (that particular image) or do you have it on you? 15-20% from what base value, same wing without slats or the same wing with washout?

 

Would like to see more info about the document from messermeister, who mentioned it in the first place.

 

 

what im interested in though is, why the P51 flaps do help by such a margin in sustained turns, while there is no gain whatsoever in the 109 when using them...

 

Yeah, from what Yo-Yo told us earlier the flaps should help in instantaneous turn. Not sustained one. I too would like to know why this is so. :joystick:

 

How much do they help? Low and slow the 109 turns far better from my experience, especially if you turn left.

 

Perhaps another thread with Tacview data comparing the two together would be interesting...

Edited May 9, 2015 by T}{OR
edited for clarity

[Ala13_ManOWar]

But P-51 and 109, do you have any turn time chart or something like to say one or the other turn more than it should like if any of us would ever fly the real ones to say that? If you compare to nothing it's impossible to make statements like that. Understand you all just sound like "this has to be like this because I say so", for both points. Based on what do you compare both planes? If I were you I would like to have something in my hand to make tests so I could really say something with a reason to say.

 

S!

Edited May 9, 2015 by Ala13_ManOWar