K4 Accelerated Wing Stall

you look to be trolling me. Enjoy.

It is you who are trolling this thread. You don't even fly the 109.I can't make it more obvious than that.

The 109 overclimbs.By how much only the devs know.

The flaps give no advantage in turning.

Finish, german, british testi pilots all belive the 109 had mild stall characteristics.But the 109 in game stalls all over the place sometimes it's on the edge of stall at over 400km'h.

Of course with a extended warthog the 109 might be a joy to fly. What do I know.

You don't even fly the 109.

I don't have to fly the 109 to be able to point out logical fallacies others are making in their discussions about the aircraft. Don't assume, simply because I oppose someone who's making (with a fallacious argument) one claim about a subject, that I believe the polar opposite claim. The world isn't black & white, see.

That is, one can point out the invalidity of someone's weak evidence, without proving (or making a claim about) the contrary position. This isn't a binary problem. My point isn't whether or not the virtual 109 is right or wrong; in this, I make no claim in either direction, because I see insufficient evidence for either case.

Rather, I pointed out that the things which your friend is using to try to support his case, cannot be used to support his case, and I explained why. If you truly do not understand this, then I am sorry for you. But I still believe you to be trolling me, instead, as a glance at your past posts indicates that you "stalk" me (the fact that you knew that I don't own the 109 module, when I didn't even remember your name, was a red flag; a quick check confirmed that you have a history of attacking my posts).

Okay, regardless of whether I'm being trolled, I will assume (ha) that someone may be reading who actually cares about the truth of the matter, and so, the old P-40 / A6M story:

I once saw a wartime comparison of a P-40 and a captured A6M, in which the test pilots compared acceleration from a level start. The P-40 pilot's report contained both his written description of the test, and also the numbers in a later portion of the report.

Someone on a forum for a different, older flight sim/game linked to the first part of the test, in which the P-40 pilot said that the P-40 accelerated "very rapidly" away from the Zero. The forum-goers began clamoring, then, that the in-game P-40 and/or Zero must be wrong, because the difference in acceleration between the two virtual aircraft was barely noticeable in-game. After all, the real pilot said it should accelerate away "very rapidly!"

Well, someone then linked to the second part of the test, where the same P-40 pilot actually gave the numbers: the P-40 got roughly 400 feet ahead of the Zero after one minute.

You see the problem now? All of the simmers were like, "But 400 ft/min is very slow! That's never going to be enough to get out of gun range. How could he call it 'rapid'?" And to us flight simmers, who are trying to get out of virtual gun range, only gaining 400 feet on the bandit, in an entire minute of running, is indeed slow. But to the test pilot, making his out-of-combat comparison, the same figure felt "very rapid."

Moral of the story: just because a real pilot calls something "very rapid" or "very gentle," does not mean that it's the same degree of rapidity or gentleness which you imagine when you hear those words, nor which you mean when you say them. One man's X can be another man's Y, when subjective terms are concerned.

The pilot is not wrong to call it "fast," nor are you wrong to call the same thing "slow;" however, all must understand that these are subjective terms, and thus mean different things to different people (and/or under different circumstances). This is why you cannot use a real pilot's assertion that a stall is "very gentle" to try to prove that the simulator is wrong. Exactly how gentle is "very gentle"? We need figures (and, moreover, figures from careful & methodical tests, not casual & inconsistent ones); subjective opinions, particularly second-hand, cannot make an accurate simulation.

The implementation of the controls stiffening behaviour was just one attempt to explain an "unexpected" behaviour of the plane - which was entering a stall.

 

If we agree upon the fact that only the deflection of the virtual stick is relevant for the aircraft - regardless of how the relation of physical and virtual stick actually is implemented - the main question seems to be: should the aircraft able to enter a stall?

 

Page.Down, why should it not? If you pull too much on the (virtual) stick for a given airspeed, the aircraft will depart.

 

So what is your evidence that the aircraft should not depart into a stall in the situations that you have recorded?

Ok, that I can understand. :thumbup:

I just disagree with it; But, David put it another way, that does make sense, maybe it's something that cannot be seen to a similar extent that Zalty tried to explain that he may not have made clear. It would explain the stall still being there the way zalty tried to explain it.

Rather it's right or not isn't what I'm discussing; The stall feels out of place at the speed in which it occurs based on the AOA used according to the Virtual and my physical inputs, and the fact that slats are deployed;

I think what I'm ultimately trying to say is the stall shouldn't be there because the K4 hasn't bled off enough speed yet.

This stall behavior is even visible in the vertical on the K4, and is naturally amplified to a higher degree on the Dora. It would explain why I can't seem to follow "AI" P51's in the vertical at the same energy states on the Dora. And is likely to be an issue with the P51 as well.

That's all I'm trying to say. Either I'm right or I'm not. It just doesn't feel right at that speed.

... I have seen a veritable plethora of evidence to support my claim ...

Good Lord! He uttered *that* word! :D

A stall can happen at any airspeed and at any attitude, It is dependent on angle of attack. If you pull back on the stick and exceed a wing's maximum AoA the plane will stall no exceptions, With or without slats or other high lift devices.

Airplanes like the Bf-109, so I have been told, had very high stick forces and the pressure required to pull the stick and raise the AoA at a given speed must have been pretty high, DCS as with many sims tries to simulate this by making you pull further back on your stick. eventually your virtual pilot may not be strong enough to pull the stick far back enough to exceed the wings maximum angle of attack. I think that this happens at a higher airspeed in DCS vs Il-2 or whatever.

Well in theory, and I've seen and tested it in game... throttling back would be unnecessary... If I lessen up on my pull the 109 will maintain speed indefinitely unless I pull a harder AOA and as such speed drops and the stall issue becomes more relevant.

 

I dunno honestly.... What I wouldn't give to get a feel for the real stick forces of the 109.

Did you give it a try with less power?

Unless I am mistaken, 40" in 109 equals about 1.4 ATA? If so, this is the maximum power this plane was flown in the flight test report you linked earlier. It mentions 30" being used on several occasions and 40" for take off:

http://www.eaf51.org/newweb/Documenti/Storia/Flying_%20109_ENG.pdf

 

Read the handling section; It talks about slats allowing for higher AOA at lower speeds. And in order to induce that wing stall it was described as crass to get the wing to drop.

Of course with a extended warthog the 109 might be a joy to fly. What do I know.

And that is exactly what Echo38 is talking about. For me (Hog extended 7cm), the plane is rock solid and only "ham-fisting" the stick will cause it to stall.

By all accounts, Spitfire will be even worse since DCS from what I understand is trying to model realistic stick travel distances:

You think that Mk IX will make you an absolute winner?

I have bad news for those who consider P-51 too stick sensitive and thus prone to stall... :)

As Spitfire has neutral stability there is only 3/4" of stick travel to stall as it was reported by NACA. Really silk hands or full scale joystick required... :)

It will be no mercy, hardcore only - all will be as Mitchell designed.

From my own testing I think that the issue here might be caused by lack of buffeting during flight with slats open. That causes people to think that stall is rapid while slats are deployed way before the stall. There is just not enough warning before it happens. I was never able to go into a spin in the 109 so I think it is very forgiving.

I don't see any problem with stick travel though.

Ive read through the entire thread carefuly (slow day at work :music_whistling:) and all I can say is that the OP doesn't seem to understand how the relation between the physical stick works in relation to the virtual joystick, which is strange as multiple people have explained the relationship very clearly in this thread.

This is a sticking point in particular: As the wind speed (over the wing) drops the stiffening forces drop and our virtual pilot can pull the virtual stick more to match the deflection of your 'real' joystick. I don't think it can be explained more clearly without drawing some diagrams.

From my own testing I think that the issue here might be caused by lack of buffeting during flight with slats open. That causes people to think that stall is rapid while slats are deployed way before the stall. There is just not enough warning before it happens. I was never able to go into a spin in the 109 so I think it is very forgiving.

 

I don't see any problem with stick travel though.

+1. Further, I've heard stories of an audible 'bang' as slats were deployed in 109s (which allegedly 'scared' inexperienced pilots) and wonder if this sound effect was added in DCS it might give us an extra vital cue of slat deployment before full stall

I think I read about that 'bang' here before. IIRC those discussions didn't come to any solid conclusion but it was assumed the bang was caused by a slat that was stuck and then suddenly deployed.

I could be completely wrong though. It's been a while.

Regarding the stall warning I think the Bf 109 gives plenty of warning compared to the P-51 or Fw 190.

Also, compared to the other fighters we currently have in DCS a stall in the Bf 109 is pretty forgiving and by no means as violent as it is in the P-51 or the Fw 190 (IMO).

If anyone has any good info on the 'bang' I could submit it, although ED does have pilot contacts too... I am always for adding more audio queues...

 

Anyways, back on topic :)

I found this, but no idea how reliable this is:

http://www.virtualpilots.fi/feature/articles/109myths/

"The Bf 109s also had leading edge slats. When the 109 was flown, advertently or inadvertently, too slow, the slats shot forward out of the wing, sometimes with a loud bang which could be heard above the noise of the engine. Many times the slats coming out frightenened young pilots when they flew the Bf 109 for the first time in combat. One often flew near the stalling speed in combat, not only when flying straight and level but especially when turning and climbing. Sometimes the slats would suddenly fly out with a bang as if one had been hit, especially when one had throttled back to bank steeply.

That quote implies that the bang was very dependend on the rate at which the AoA increased. Interesting.

Ive read through the entire thread carefuly (slow day at work :music_whistling:) and all I can say is that the OP doesn't seem to understand how the relation between the physical stick works in relation to the virtual joystick, which is strange as multiple people have explained the relationship very clearly in this thread.

 

This is a sticking point in particular: As the wind speed (over the wing) drops the stiffening forces drop and our virtual pilot can pull the virtual stick more to match the deflection of your 'real' joystick. I don't think it can be explained more clearly without drawing some diagrams.

The stall does not line up; with the virtual joystick. And based on feel what the virtual joystick shows as my location or pull intensity is what I have said from the start of the thread.

The point is the stall is occuring at lower AOA's than should be possible.

The videos show this consistency.

Thor:

Quote:

Originally Posted by Page.Down View Post

Of course with a extended warthog the 109 might be a joy to fly. What do I know.

I never said this. I think you might be quoting someone else.

+1. Further, I've heard stories of an audible 'bang' as slats were deployed in 109s (which allegedly 'scared' inexperienced pilots) and wonder if this sound effect was added in DCS it might give us an extra vital cue of slat deployment before full stall

The slats were not a warning point for a stall; Inexperienced German pilots used it as such, and were under the presumption that they were pulling to many G's.

An experienced Ace pilot has always contradicted this pilot account, and even stated newer inexperienced pilots were afraid to push a 109 that hard.

ME-109E's were known to turn with early model spitfires in sustained turns; But an inexperienced pilot would not have been able to.

That quote implies that the bang was very dependend on the rate at which the AoA increased. Interesting.

Also note:

The slats were described in flight test reports as being collapsible with one finger's worth of pressure.

Hardly representative of an indication of stall.

From what I read, the 'bang' was scary for inexperienced pilots because they thought they were being hit. But I have asked for clarification from ED's contact with their 109 pilot to see if he can confirm or deny being able to hear them deploy at any time.

Fair enough,

But rather or not it is modeled is not an indication of stall. I don't think people should get in the habit of that assumption.

Especially since it only required one finger's worth of pressure to collapse them.

They were not meant as a stall warning mechanic.

No, and I never said it was, I purely interested in knowing if they could be heard during a flight. Its really kinda off topic from your original post at this point.

Ahh ok. Eyecandy then.

Or Earcandy.... :)