Slats deploying at high speed ?

Funny you should say that since we have seen the opposite from you, twice already. Apparently the document from 1944 is more accurate than the revision from 1954 that replaces it (after 10 years of service life!). Had you looked more closely you would have seen that the initial 1944 version is by large a direct copy from 1943 manual for an earlier version of the same plane. And all subsequent variants from 1945 to 1947 have more and more pieces from the original 1943 document deleted (that contradict one another) - up to the complete revision in 1954. But the latter one doesn't cater to your theoretical arguments. :)

 

Here is a friendly advice to you: stop quoting others and selectively picking data which suites your theoretical arguments that you read somewhere and apparently take for granted. Instead, if you feel that something is off, do the math yourself. That way people might actually start listening to you since you do have some interesting things to say. Also, passively insulting people that their comments are "false and completely illogical" doesn't help you in winning them over either.

I have absolutely no idea what you're talking about...

Take it to PMs guys, it's pointless to poison every odd thread with your personal feud.

No need. I've dissipated enough energy as it is. Apologies for OT.

Sorry, wrong thread.

I think this book explains clearly what was the behavior of automatic slotted slats, and how they were used.

I think this book explains clearly what was the behavior of automatic slotted slats, and how they were used.

S!

Otto, that ""explains"" nothing at all... :music_whistling: If something it says your wishes...

 

S!

BpTrygZfC-g

min 4.27 "There is evidence that a 109 would turn tighter than a spitfire".

I don't want the 109k to outurn a spifire mk14 for example.Not to mention a spit 9.

But what i see in DCS the 109 turns performance is too close to the mustang which is a ton heavier has laminar wings(that aren't great for low speed turning) and doesn't have slats.

Plus the 109 at the moment has a 30m/s climg rate that is higher than historical and that should also help in it's turning performance.

I would be ready to belive the low speed performance the 109 has in DCS because i see Yo-Yo as a talented FM creator but the way it falls on one wing and hangs/stops then twiches it just doesn't match at all what i read about the 109.

But what i see in DCS the 109 turns performance is too close to the mustang which is a ton heavier has laminar wings(that aren't great for low speed turning) and doesn't have slats.

First of all, I just want to put it out there that I love all the current WWII prop planes we have in DCS.

Now I'll just throw in my observation based on nothing more than my experience flying these wonderful DCS crates ... IMO the Bf109 has superior turn performance because its a smaller circle, a better rate of turn and because it regains energy easily after a tight turn.

Note that while the Bf109 has slats, the P51 has maneuver flaps ...

IMO the P51 with 1 notch of flaps doesn't turn as tight nor as quickly though it does a pretty darn good job ... and the main drawback is that it's a whole lot harder to regain energy unless the P51 has plenty of altitude to begin with. But then the Mustang isn't a turn and burn plane either.

So to end of my subjective take on this ... I disagree that the P51 has comparable turn performance ... :)

I recall reading a quote from Adolf Galland that of all the allied planes he favoured the Mustang (I believe he got to fly one) .. why? Because it reminded him of the Bf109 but with longer range!

I might have read it in his memoir's "The First and the Last" though I'm not 100% sure of that.

Note that while the Bf109 has slats, the P51 has maneuver flaps ...

You no doubt already know this, but just in case: the Combat flap setting on the P-51 is simply normal flaps, deployed 10 degrees. It isn't like the 8-degree Maneuver setting on the P-38's Fowler flaps, which does something that normal flaps don't (namely, increasing the surface area of the wing). None of the aircraft currently scheduled to be in DCS: WWII have Fowler-type flaps. The only WWII fighters I'm aware of that had Fowlers were the P-38 and a few of the Japanese fighters, such as the Oscar and Frank. AFAIK, P-38 was the only Fowler-equipped prop fighter on the Western front, at least that made it into mass-production. Fighters which didn't have 'em included the P-51, FW 190, Me 109, P-47, and Spitfire.

The P-38's Fowler flaps are also not to be confused with the dive flaps--not airbrakes--on the P-38L (and some Js), so the P-38L actually had two separate types of unconventional flaps.

IIRC, the FW 190 had the same system as the P-51--a "combat" setting which allowed easy access to the 10-degree setting. Don't remember for sure, though.

You no doubt already know this, but just in case: the Combat flap setting on the P-51 is simply normal flaps, deployed 10 degrees. It isn't like the 8-degree Maneuver setting on the P-38's Fowler flaps,

 

<snipped some REALLY interesting stuff! :thumbup:>

 

Ah forgive my ignorance .. I wasn't aware of a functional distinction in that I thought the combat flap setting on the P-51 was a legitimate method to enhance maneuvering authority?

I thought the combat flap setting on the P-51 was a legitimate method to enhance maneuvering authority?

It is. However, it's nothing special in terms of how the flaps work--it's just lowering the flaps 10 degrees. The only reason it's a special setting is for convenience's sake. Some fighters (Spitfire? 109? don't remember) made you hold the flap lever down until they were at the right setting, so you had to work to get the flaps at ~10 degrees. The P-51 & FW 190 (?)'s combat settings were just there to be handy--that is, to reduce pilot workload by making the 10 degree setting readily available via detent (throttle switch, in the FW 190's case, I think? it's been a long time, don't recall).

The P-38's not only did that, but also "something extra" (better lift/drag than conventional & split flaps, 'coz increasing wing area). In period literature (manuals and other documents) that I've seen, this distinction is made by referring to "Combat" and "Maneuvering" flaps, respectively (the P-51's being "combat flaps," and the P-38's being "maneuver flaps" or "manuvering flaps"). I've noticed the two terms being used distinctly & consistently in the manuals etc.

So, my point is, there's a distinction in terminology in all of the period literature I've seen; in fighters with conventional or split flaps, which have a special setting to lower them 10 degrees, it was called "combat flaps," while in the P-38, which had Fowler flaps, the setting that put them to the 8-degree mark was called "maneuver flaps." The distinction in terminology comes, no doubt, from the clear distinction in their function as flaps (as opposed to any "within the cockpit" distinction, applying only to the pilot's workload / interface for lowering them); the Lightning's 8-degree Maneuver setting maximized the "extending" function, but minimized the "lowering" function, making it the best possible setting for having max lift with the least drag--or something like that.

Because conventional & split flaps don't extend wing area, no such "max extension / min lowering" setting was possible. Can't maximize wing-area extension if the flaps don't extend the wing area, see. Hence the distinction in terminology. If anyone knows what I'm talking about, please do feel free to rephrase it--I suck at trying to explain things.

@Echo38 .. if I could I'd rep you! Thanks for the explanation, I think you did an exceptional job!

However, are you also saying that the P51 as modeled shouldn't (in your opinion) have the turning authority it currently enjoys?

However, are you also saying that the P51 as modeled shouldn't (in your opinion) have the turning authority it currently enjoys?

No, I'm not saying that; but neither am I saying the opposite, mind you. I don't have enough information about the real P-51 to have a solid opinion on whether or not the DCS: P-51D is accurate or not in its turning characteristics. If it were a P-38J or L, maybe I'd be comfortable in offering an opinion, since I did some fairly heavy-duty research on late-model P-38s, back in the day. But even then, without having flown one for real, it'd be nothing more than a relatively-educated guess.

Would be even less comfortable in commenting on the DCS Me 109K's turning ability, given that I haven't even had the opportunity to fly it in the sim. Just making a clarification on the different types of flaps & {systems for lowering them into specific positions} (or lack thereof), & the {reasons for / benefits of} those specific positions.

So, to conclude: I'd expect the 109's flaps, if lowered 10 degrees, to be roughly as effective as the P-51's flaps, lowered to the 10-degree combat setting. That is ignoring all other factors, such as general airframe drag and P/W ratio and all that--when accounting for these things, one aircraft or the other might be "more comfortable" at that flap setting, due to greater ability to overcome the drag. But, AFAIK, there is no great distinction between the P-51's flaps at 10deg and the 109's flaps at 10deg, speaking of the flaps themselves. Definitely neither are Fowlers and neither does anything else similarly-unusual at the 10-degree setting (or any other). The major difference (relevant to the discussion) between the P-51's and the 109's, is that the P-51 has a handy "combat" setting to get them to the 10-degree angle more easily. : )

(The 109 has the leading-edge slats to make up for the lack of a 10-deg flaps shortcut, so don't feel too sorry for it!)

are you sure?

what AoA do you have in a flat spin?:music_whistling:

III/JG52_Otto,

this one is a BASIC one ..., Hmmm, you missed a good opportunity to remain silent :-)

Those who already answered 60+ degrees are absolutely correct!

Otto, I have stalled my glider due to sudden updrafts flying over the mountains. Know why? Because all of a sudden the relative wind varies from a few degrees to almost 80+.... It comes from bellow, all of a sudden....

this one is a BASIC one ..., Hmmm, you missed a good opportunity to remain silent :-)

S!

... min 4.27 "There is evidence that a 109 would turn tighter than a spitfire". ...

Not to mention what Sithspawn said, you want to get into de sim and do same things ace pilots stories tell the very first time you "fly", while RL says 95% of the pilots were average at most and they didn't mastered nor even try such kind of things. Reading aces stories don't make you one of them... :music_whistling: At best we are all in the 95% average with a few exceptions.

S!

Not to mention what Sithspawn said, you want to get into de sim and do same things ace pilots stories

S!

Sithspawn post is condescending nothing more .

Sithspawn said nothing is wrong with the way 109 wings broke.And i had to take the time to prove he was wrong.

I don't want to take the time to prove him wrong again.

Sithspawn post is condescending nothing more

And don't get me wrong, I don't mean to sound acquiescent or harsh to people, but I know quite good that because I've been a simulator fan since my childhood and my knowledge while reached a wide spread with time was really very limited in RL deep concepts and some flying basics. Then I got my licence and realised how many things I didn't really knew or knew wrongly... You have to accept that because that's the crude reality. Not to mention the lack of feeling makes you think an aircraft behaves quite different it really behave.

For instance, a clear misconception, here some people are still arguing why you stall turning sharp even at high speed, and they don't want to understand the really basic concept that you stall by AoA and not speed... I think that shows exactly my point. The feature we are talking about may be OK or may be wrong, but you cannot defend it's wrong because you don't know nor understand flight basics. That leaves you with no point from start. So, we all want the perfect simulator, the closest to the real thing, but IMHO you aren't helping to get there if your points are based on a false statement from a starting misconception (I don't mean YOU nor anybody in particular). I think we all have to be self critical before thinking everything is wrong but us.

S!

I think this book explains

For this reason, it is possible to find pilots from 1940 who will tell you that the spitfire turned better than Bf-109...

I myself had many dogfights with Spitfires and could always out-turn them."

Spitfire pilot say:

:D

I'd put my faith in what Skip Holm & Mark Hanna have said, that the 109 & Spit are very close when it comes to turning and that both are excellent dogfighters.

Btw, I remember watching Bf-109 Red 7, a G-4, complete several sustained turns during an airshow, and none took over 18 seconds to complete. The pilot again is ofcourse highly trained, and knows the limits of the aircraft better than the pilots back then as his understanding of the various subsystems and the aerodynamics is vastly better (he knows what the slats are there for, how & why they operate in every detail), which explains why he is able to do that despite the low power settings used.

Stalling depends of angle of attack, not airspeed. That is why you see the slats deploy at 400km/h.:thumbup:

The Slats are actually Pressure deployed......

But yes not airspeed.

I'd put my faith in what Skip Holm & Mark Hanna have said, that the 109 & Spit are very close when it comes to turning and that both are excellent dogfighters.

 

Btw, I remember watching Bf-109 Red 7, a G-4, complete several sustained turns during an airshow, and none took over 18 seconds to complete. The pilot again is ofcourse highly trained, and knows the limits of the aircraft better than the pilots back then as his understanding of the various subsystems and the aerodynamics is vastly better (he knows what the slats are there for, how & why they operate in every detail), which explains why he is able to do that despite the low power settings used.

20º/s in a sustained turn ? Not bad for a 109 :) Think I would be able to catch some thermals with it :-)

20º/s in a sustained turn ? Not bad for a 109 :) Think I would be able to catch some thermals with it :-)

Again without MW50 system (tank and other parts) ammo and weapons, and probably 25min of fuel for an airshow (they won't take full 1h load for that).

Try that load in DCS. And remember that G4 is lighter than K4 anyway.