K4 Accelerated Wing Stall

[[DBS]TH0R]

If you remember discussions earlier in the thread the 109 is a dream to handle at or below 250 mph. Note: 250 mph = 402.336 km/h.

 

I repeat my question Echo; Why is the K4 stalling like it is at 380-420km/h? or 236 to 260 mph? According to others in this thread, and pilot accounts; The K4 should get it's best AOA and turn radius at those speeds when you factor in slats; My Videos clearly show the possibility of premature buffeting & stall mechanic at not only lower speeds but lower AOA's.

 

It has been answered to you several times already in this thread. Above 400 km/h the stiffening starts to become more apparent. Between 300 - 400 km/h it is hardly noticeable, you can almost disregard it.

 

The 380-420 km/h is a "transitional" area. You started your turn at 500 km/h and speed dropped to that particular range. You can not, and I repeat can not, simply hold your desktop joystick at a constant pull throughout this maneuver. As you lose your speed, the forces required to hold your virtual stick will decrease thus moving the virtual joystick further back to match the physical joystick on your desk and as such increasing AOA. This is evident when looking at the 3D joystick in the cockpit. The joystick indicator, at least for me, doesn't show such small movement.

 

Now, what might be causing problems for some is the relatively short travel required to do any meaningful maneuver with a desktop joystick. I will draw a comparison here. Coming back from IL21946 I always flew with 100 settings on all axes. I just like to have the full control over my plane. For some people this was unthinkable and way too sensitive. DCS 109 is just like that. It requires very little stick input in any direction for all maneuvers. That is why I presume some people have problems with it. But this is how DCS simulates pitch and roll for all WWII birds. It doesn't try to accommodate for desktop joysticks last I checked - for that you need to add some curves under controller settings. Based on what Yo-Yo said - if you think 109 is "twitchy" just wait until we get the Spitfire...

 

^^

Edited and underlined for (even) more clear explanation.

 

 

Well i'm only going to say this: you guys who are still flying DCS WW2 birds without FFB stick are missing so much. I would never fly without it again. Over and out...:joystick:

 

Having tested FF last night I will say that even though buffeting feels nice and gives you 2-3 times more warning and ability to fly on the edge, I dislike the rest of the FF implementation / modeling. After using an extended joystick for quite some time now I can never go back. The added fidelity is greater advantage than FF.

Edited April 29, 2015 by T}{OR
spelling

[NineLine]

Guys, if this is just going to be a bunch of arguments about who thinks they are more right then I will shut it down, so far I haven't seen anything too convincing, so bring some data or accept the FM and EDs version...

[Page.Down]

It has been answered to you several times already in this thread. Above 400 km/h the stiffening starts to become more apparent. Between 300 - 400 km/h it is hardly noticeable, you can almost disregard it.

 

The 380-420 km/h is a "transitional" area. You started your turn at 500 km/h and speed dropped to that particular range. You can not, and I repeat can not, simply hold your joystick at a constant pull throughout this maneuver.

 

No offense then Thor, and don't take this the wrong way, but I don't think you have a firm grasp on physics, or aerodynamics to say that.

 

I don't mean that the way it sounds; But, everything I know of physics and aerodynamics tells me that something is wrong with the K4 at those speeds.

 

I've made it clear why people cannot simply assume that's how it is:

 

 

1. The AOA was established at 500km/h NOT 380-420km/h

 

2. IF AOA is maintained from the initial point; Then according to physics and aerodynamics as speed decreases buffeting stops at lower speeds; Why? Because given the use of slats, and the way physics and aerodynamic relationships work; You can now increase your AOA to the point of buffeting which changes with speed, temperature, air pressure, and altitude.

 

3. Furthermore according to Physics and Aerodynamic properties; Given the AOA was established at the higher speed and is theoretically more shallow than the possible AOA at 380-420km/h At some point the plane will hit a speed at which it simply will not go below and begin to maintain that speed. Any real life pilot, or veteran of simulators can attest to that fact.

 

I don't know how many ways I can say that so that people can understand it; I'm not a teacher, but I am a student and always will be.

[ZaltysZ]

Having tested FF last night I will say that even though buffeting feels nice and gives you 2-3 times more warning and ability to fly on the edge, I dislike the rest of the FF implementation / modeling. After using an extended joystick for quite some time now I can never go back. The added fidelity is greater advantage than FF.

 

Theoretically, if FFB was done right and you set FFB forces high enough, you should have more natural handling going through wide speed range in turns/loops. Strong FFB force should make it very obvious when to stop pulling, if you didn't want to pull more when virtual pilot, and that would solve overcontrol issues while slowing down.

[Flagrum]

Page.Down, the part you did not get was probably

You require a proof that "I have seen a veritable plethora of evidence to support my claim that various people use the same word to mean different things."

You took that quote of Echo as an example where he "claims" something but provides no proof. The thing is, he only claims that "sometimes different people use the same word differently". It is just an observation, common sense if you like. He was not talking about the aircraft or claims that were made in regards to the aircraft - just that people often are inprecise.

Example "very stiff controls" is not scientific or "hard evidence" -> people use the word "very" but mean different things.

That was all he said.

 

The only thing I understood in your post was this:

 

Firstly; Yes it is logic; Something that escapes Echo.

No. He said, one is able to point out errors in an argumentation without having to support any side of that argumentation. That is possible by applying the rules of logic. That is what he did.

Secondly, to answer your question, why should I? I asked a question people answered, However, echo found it more constructive not to make a single post in this thread to contribute to it in any way shape or form.

 

Instead, he chose to argue with otto and hummingbird;

 

None of the drivel that he spewed in this thread had anything to do with the thread itself.

No. He did contribute in that way that he pointed out that one or the other side of the argumentation was not sufficient to prove or disprove the other side. He tried to make the whole discussion as whole (more) meaningfull.

 

So; He demands of me proof of my claims; He clearly fails to logically understand what the videos I have posted show. What gives him the right when he hasn't contributed to the discussion like you have?

 

I don't require proof of it from you because you contributed to the discussion in a respectable way. In a logical way.

 

I didn't require it of anyone in this thread at any point in time; But I have no right to challenge Echo when he demands it of me?

 

Is that logical to you?

Yes, it is. See my comments above.

 

I didn't think so either.

Wut? :o)

 

Needless to say; I have no obligation to entertain him any further.

 

In conclusion:

ED modelled it the way it is. They did so based on their research, knowledge and experience - it is the best they can atm come up with. I trust ED that they do not model the behaviour that way just out of blue air.

If one now thinks, something is wrong and that he has better, more correct information, then he should provide it to ED. Relative terms like "very" or "feels like" are not better information, they are not even information but just emotions.

 

Personally, I yet have to see any hard evidence that support your claims, Page.Down. But I admit, that my lack of knowledge in this area is at least partially responsible for that.

But you say, your evidence can be found in your videos. Ok, so for a layman like me, correct me where I am wrong:

1. A stall situation occurs when the AoA is too big for a given airspeed.

2. A stall can occur at ANY airspeed - given that the AoA is too big.

3. At an AoA that corresponds to the best turn rate at a certain airspeed, no stall should occur (or "can not occur" by definition).

4. You are now saying, at the airpseed shown in your videos and the AoA you were inducing, no stall should occur.

Why not? What exactly was your AoA? Did you in fact try to archieve the best turn rate? What turn rate (numbers!) would that be in theory (regarding the documents) and in your experience (how measured in your videos)?

[[DBS]TH0R]

No offense then Thor, and don't take this the wrong way, but I don't think you have a firm grasp on physics, or aerodynamics to say that.

 

None taken. I guess I should just throw my masters degree in mechanical engineering out through the window then. :)

 

Joking aside, I was replying to your claim that you maintained a constant AOA established at a higher speed. What we all are trying to explain to you is how sick stiffening dependent on your speed is simulated in this sim. With that being said, please read my last post again, don't just cherry pick a piece of it as a quote.

 

 

 

EDIT in order not to double post:

 

 

Theoretically, if FFB was done right and you set FFB forces high enough, you should have more natural handling going through wide speed range in turns/loops. Strong FFB force should make it very obvious when to stop pulling, if you didn't want to pull more when virtual pilot, and that would solve overcontrol issues while slowing down.

 

Exactly. This is somewhat how old IL2 simulated stick forces. Sadly, MS dropped their support for the FF2 stick and we're stuck with default setting with any such controls or fine tuning absent both in DCS or in OS.

Edited April 29, 2015 by T}{OR

[ZaltysZ]

1. The AOA was established at 500km/h NOT 380-420km/h

 

2. IF AOA is maintained from the initial point; Then according to physics and aerodynamics as speed decreases buffeting stops at lower speeds; Why? Because given the use of slats, and the way physics and aerodynamic relationships work; You can now increase your AOA to the point of buffeting which changes with speed, temperature, air pressure, and altitude.

 

If AOA is maintained... Are you sure it is maintained? Multiple people have already said in multiple ways, that current control stiffening model makes it hard to maintain the same AoA without changing stick position, but you just brush it off everytime by interpreting us in bizarre ways.

 

Get Tacview, make it export telemetry data and do your test. Then watch how well that AoA is maintained by you. You can get AoA, Gs and other readings at every point of Tacview track.

Edited April 29, 2015 by ZaltysZ

[OnlyforDCS]

....Furthermore according to Physics and Aerodynamic properties....

 

 

You are claiming (as far as I can tell, but correct me if Im wrong) that a K4 that is experiencing buffeting at a given speed and specific AoA, will stop buffeting if the speed is reduced but the AoA is maintained.

 

Now Im just a humble simmer here, but isn't that exactly the opposite of what should occur?

 

I mean every plane Ive ever flown behaves in the exact opposite way, If im close to stalling, I either have to increase speed, or reduce AoA.

[Echo38]

[massive wall o' text]

 

I have been known, from time to time, to mistake a trolling attempt for a legitimate disagreement, but, sometimes, it's clear even to me which a post be. Not gonna bite, my friend! Do have a nice day, though : )

[Solty]

Does this sound familiar Echo?

 

 

 

Where's that proof Echo? Why am I suddenly bound to prove my point to you when you can't even prove your point to others?

 

Does this look familiar Echo?

 

 

 

Echo Stop me if you've heard me say this before:

 

 

 

 

How about this fact: For those of us who know how to convert km/h to mph: 300km/h = 186.411 mph. Anyone still think control stiffening is an issue at 300km/h?

 

If you remember discussions earlier in the thread the 109 is a dream to handle at or below 250 mph. Note: 250 mph = 402.336 km/h.

 

I repeat my question Echo; Why is the K4 stalling like it is at 380-420km/h? or 236 to 260 mph? According to others in this thread, and pilot accounts; The K4 should get it's best AOA and turn radius at those speeds when you factor in slats; My Videos clearly show the possibility of premature buffeting & stall mechanic at not only lower speeds but lower AOA's.

 

But for some odd reason Echo, you absolve yourself from burden of proof, and simply say that I am wrong, but I need to prove my point.

 

Ok; Here's a new video with some peculiar inconsistencies with the K4 Flight Model.

 

 

That being said, I will no longer indulge you from this point forward. You are entitled to your opinions.

a) K4 in game doesn't have flettner tabs.

b) Flettner tabs are not adjustable from the cockpit.

c) What you change is horizontal stabiliser trim.

 

At (around)400kph you are capable to stall out. But you can also pull the fastest turn. So where is the problem? You can pull enough to stall. Slats don't stop you from stalling. They are there to give you better CLmax... but that doesn't mean that it is stall proof.

 

Stall is not fixed to a single speed range. You can stall every plane if you have strenght to do that. (or if the plane will be able to withstand such forces)

Stalling speed is indication at what speed the plane doesn't have enough lift to continue flying straight.

 

For example a Spitfire is going to struggle a lot more to pull out of a high speed dive over a 109, while a P51 will struggle far less than a 109, likewise for a Dora.

That is completely incorrect. The spitfire(mkIX) has way better elevator control and similar (although marignally better) aileron control at high speed dives. What 109 pilot can do to pull out of a very high speed dive is to change horizontal stab trim.

 

 

PS. Have you ever tried to add a little bit of rudder during a turn? That helps with turn rate and stability.

PS 2. Rudder control stiffness is not applied (yet) to the FM.

Edited April 29, 2015 by Solty

[NineLine]

 

PS. Have you ever tried to add a little bit of rudder during a turn? That helps with turn rate and stability.

 

Funny, I was just looking at his vid again and was going to ask about that, there is very limited to no use of rudder it seems... Using rudder and performing similar turns I don't get the same results he is talking about here.

[[DBS]TH0R]

Funny, I was just looking at his vid again and was going to ask about that, there is very limited to no use of rudder it seems... Using rudder and performing similar turns I don't get the same results he is talking about here.

 

Same here. I find DCS 109 loves rudder input, in particular during turns. It is even mentioned in the document he linked. There is also talk about rudder getting heavy above 500 km/h.

[GrapeJam]

And the same argument can be said about stick forces; I believe avg stick forces for a 109 was said to be about 10lbs, but can get as high as 20lbs. Unlike a spitfire which can get as high as 50lbs.

 

Incorrect, the 109 had a stick force of over 20 lbs per G at 500km/h and rapidly increased as the speed got higher. The Spitfire V had a stick force of 20lbs for a 4 G pull at 400 mph with the trim set at nose heavy position.

[Page.Down]

If AOA is maintained... Are you sure it is maintained? Multiple people have already said in multiple ways, that current control stiffening model makes it hard to maintain the same AoA without changing stick position, but you just brush it off everytime by interpreting us in bizarre ways.

 

Get Tacview, make it export telemetry data and do your test. Then watch how well that AoA is maintained by you. You can get AoA, Gs and other readings at every point of Tacview track.

 

Fair point Zalty, no, I'm human, and not perfect.

 

But I also said multiple times in this thread how the devs can test it under perfect conditions.

 

IF what I claim to see is represented in that controlled perfect environment, then it confirms that the buffeting and stall mechanic is occurring to soon at lower speeds when the AOA is initiated and maintained from a higher speed. This goes against the laws of physics and aerodynamics as I understand them.

 

Maybe my understanding of those principals might be in question, but at this point I have no reason to think so yet.

[Page.Down]

Incorrect, the 109 had a stick force of over 20 lbs per G at 500km/h and rapidly increased as the speed got higher. The Spitfire V had a stick force of 20lbs for a 4 G pull at 400 mph with the trim set at nose heavy position.

 

400mph = 643.738 km/h My video was estimated of surface lock at 650km/h+ on the elevator but not the ailerons which lock up at 700km/h + (Obviously the max on the speedometer is 700km/h so it's impossible to get exact speed numbers there)

 

And I said average stick forces was about 10lbs, but can get as high as 20lbs; I made no error in my statement especially at the speed the thread is talking about which is 380km/h to 420km/h a HUGE difference in stick force from 643km/h don't you think Grape?

 

So to pull 6G's at 500km/h 120lbs of stick force; You do realize some planes had 80-120lbs of stick force at lower speeds? So while yes it required 2 hands, it wasn't impossible or even close to it at 500km/h. And I don't think your per G suggestion is correct either since there are pilot accounts of pulling the elevator at 700km/h in the 109.

 

And I said nothing about a Spit V which had a redesign of the fuselage compared to early model spitfires.

 

And if you saw the same report I did; Stick forces at 380-420km/h is a non factor; When several people in this thread mentioned it regarding the basis of the thread.

Edited April 29, 2015 by Page.Down

[Page.Down]

Originally Posted by Solty View Post

 

PS. Have you ever tried to add a little bit of rudder during a turn? That helps with turn rate and stability.

 

Funny, I was just looking at his vid again and was going to ask about that, there is very limited to no use of rudder it seems... Using rudder and performing similar turns I don't get the same results he is talking about here.

 

That is why I specifically noted it in my video that I didn't test rudder control at 700km/h+. Because I didn't think to try until after I made the video. At some point I will test the situation again only this time trying to see if rudder control will balance out the roll on the K4 when all other surfaces are locked. It might allow me to recover from that dive.

[NineLine]

That is why I specifically noted it in my video that I didn't test rudder control at 700km/h+. Because I didn't think to try until after I made the video. At some point I will test the situation again only this time trying to see if rudder control will balance out the roll on the K4 when all other surfaces are locked. It might allow me to recover from that dive.

 

So this is the problem with this report, I am not sure you are flying the aircraft the way you should, you cant challenge the FM if you are unable to fly the aircraft the way it was when it was tested... getting back to my original point in this thread. To use pilot notes for testing and comparing you have to mimic the test conditions pretty close, this include flying the aircraft correctly.

[Page.Down]

So this is the problem with this report, I am not sure you are flying the aircraft the way you should, you cant challenge the FM if you are unable to fly the aircraft the way it was when it was tested... getting back to my original point in this thread. To use pilot notes for testing and comparing you have to mimic the test conditions pretty close, this include flying the aircraft correctly.

 

Can you instruct me on how to fly the plane correctly for the purpose of testing the issues I saw in my recent video?

 

What exactly did I do wrong?

[NineLine]

Can you instruct me on how to fly the plane correctly for the purpose of testing the issues I saw in my recent video?

 

What exactly did I do wrong?

 

I suggest getting on some of the multiplayer servers hosting the WWII birds and talk with them, there are some good pilots there, they can help you out. I am not sure this thread is getting anyone anywhere anymore...

[Page.Down]

I suggest getting on some of the multiplayer servers hosting the WWII birds and talk with them, there are some good pilots there, they can help you out. I am not sure this thread is getting anyone anywhere anymore...

 

So I'm not flying the plane correctly, but you can't point out what I did wrong?

 

Well ok, assuming I was flying wrong, because I didn't attempt to use the rudder at 700km/h+

 

I'll make a new video of those conditions with me attempting to use the rudder.

 

Would that be a more accurate representation of the correct way of flying in the test I was attempting to conduct?

[NineLine]

Well ok, assuming I was flying wrong, because I didn't attempt to use the rudder at 700km/h+

 

I was talking about your turns, I dont think you were doing 700km/h+ in your turns... perhaps you're just trolling now.

[Page.Down]

I was talking about your turns, I dont think you were doing 700km/h+ in your turns... perhaps you're just trolling now.

 

In the recent video I made no attempt to turn at all; Nor did I say I was going to?

 

I was testing out surface lock and trimming in that video;

 

 

 

 

Now I just tested it again, and apparently I cannot reproduce surface lock at over 700km/h where I am 100% positive the surfaces were locked in my recent video; Because I was physically moving the joystick all over the place and the plane did not respond at all, nor did it pull out of the dive or even attempt to pitch up.

 

Now when I try to test the same conditions with the intention to test the rudder This is what I am now seeing. 700-800km/h Elevator authority is clearly present; The K4 does pull out even with a +2 trim setting; Aileron lock does not occur; And Rudder authority is fully present.

 

 

Sigh,

 

I give up; Apparently I'm lying, and cannot reproduce anything.

 

Feel free to lock or delete this thread;

 

Sorry for wasting everyone's time.

[Yo-Yo]

Incorrect, the 109 had a stick force of over 20 lbs per G at 500km/h and rapidly increased as the speed got higher. The Spitfire V had a stick force of 20lbs for a 4 G pull at 400 mph with the trim set at nose heavy position.

 

Sorry, must correct: lbs per G is a constant within moderate M range. It can not vary with the speed.

[NineLine]

Sorry, I am weird, I like to try and stay on topic, I was talking about your OP post and the updated video for it with the control indicator. But anyways... this thread has become painful...

 

In the recent video I made no attempt to turn at all; Nor did I say I was going to?

 

I was testing out surface lock and trimming in that video;

 

 

 

 

Now I just tested it again, and apparently I cannot reproduce surface lock at over 700km/h where I am 100% positive the surfaces were locked in my recent video; Because I was physically moving the joystick all over the place and the plane did not respond at all, nor did it pull out of the dive or even attempt to pitch up.

 

Now when I try to test the same conditions with the intention to test the rudder This is what I am now seeing. 700-800km/h Elevator authority is clearly present; The K4 does pull out even with a +2 trim setting; Aileron lock does not occur; And Rudder authority is fully present.

 

 

Sigh,

 

I give up; Apparently I'm lying, and cannot reproduce anything.

 

Feel free to lock or delete this thread;

 

Sorry for wasting everyone's time.

[Yo-Yo]

So I'm not flying the plane correctly, but you can't point out what I did wrong?

 

Well ok, assuming I was flying wrong, because I didn't attempt to use the rudder at 700km/h+

 

I'll make a new video of those conditions with me attempting to use the rudder.

 

Would that be a more accurate representation of the correct way of flying in the test I was attempting to conduct?

 

If you manage to stall the plane and feel pain doing it while other guys fly the plane safely and enjoy flying - maybe something is wrong with your way of piloting?