A-10 stall behaviour in DCS is incorrect

[Goblin]

"Damped" Dampened would mean it got wet.

 

"Damped" can also mean getting wet... Whatever :)

 

I just fired up DCS and tried the Hog for the first time since I got my Rift... Man, oh MAN, what an experience..! It rocks in VR!

 

But, that's not what I wanted to test...

I went high alpha flying, and tried some stalls. First I jettisoned stores. Didn't empty the gun though. T'was just a quick test.

Yes, the wing drops in the stall. Correct or not, it was a very docile drop! A Cessna 172 will drop the wing faster, if flown a little uncoordinated.

I'd say the stall characteristics of the Hog is very benign. Now, it may very well be that it should have even better stall characteristics. That I don't know. But I wouldn't say it's hard to control it in high AoA flight. Rudder was very responsive, for instance.

 

Edit: I should mention that I use a VKB Black Mamba stick, with an extension and cam gimbals. It has extremely good precision around center and when transitioning across pitch and roll axes, which makes it easier to make very small control inputs, without overcorrecting. I also use Slaw Viper pedals with a damper. Same thing with those. Heavy pedals with contactless sensors.

Edited August 26, 2016 by Goblin

[Goblin]

A-10C only has pitch and yaw SAS. This is mainly a roll stability issue.

 

It's not that simple... There are aerodynamic couplings between axes.

For instance, aft CG will affect yaw and pitch stability, but not roll. But a yaw, will induce a roll, so roll may be indirectly affected.

 

Better yaw stability is less likely to cause a roll upset.

[soupyc]

"Damped" Dampened would mean it got wet.

 

Sorry, I couldn't help it. A few of my friends have a running gag about the usage of "damped" versus "dampened".

 

Don't be pedantic. 'Damped' doesn't even come up as anything but the past tense of 'damp', and the definitions of the two words are the same. Someone is trying to help you and you question their word choice.

 

#2 here: http://www.dictionary.com/browse/dampened

 

This community gets more absurd and juvenile as the years go on. It's not hard to believe EDs claim that more people play single player, if this is the type of person you're likely to encounter.

[SCU]

Don't be pedantic. 'Damped' doesn't even come up as anything but the past tense of 'damp', and the definitions of the two words are the same. Someone is trying to help you and you question their word choice.

 

#2 here: http://www.dictionary.com/browse/dampened

 

This community gets more absurd and juvenile as the years go on. It's not hard to believe EDs claim that more people play single player, if this is the type of person you're likely to encounter.

 

Gentlemen, please stay civilized. We don't want this to be another closed thread. Everyone is entitled to their opinion, wrong or right, as long as it doesn't insult or offend anyone. I don't see that Gryphon offended anyone in any way except that he had an opinion (again this can be right or wrong, it doesn't matter).

[SCU]

Also, wingdrop can occur on any aircraft if flown uncoordinated (slipping).

 

The A-10C has a stability augmented flight control system. Normally this will help stabilizing (duh!) high AoA flight. Maybe just the stabilizing algorithms needs a tune in DCS?

 

Exactly. The -1 states that out of control flight conditions or "post stall gyrations (PSG's)" (Which is described as uncommanded roll reversals or roll accelerations) occur on slip angles of excess of 20 degrees, which I believe is some large deflection. I doubt such conditions are present when pitching up from a level flight with no roll included. Doing that in DCS you will still get a wing drop, which shows that this isn't dependant on sideslip in the FM.

 

The manual is absolutely clear about the "excellent" stall/post stall/spin characteristics of the A-10 and the fact that you must "severely" aggravate the stall to force a PSG ..

 

I really believe that all arguments will stop once we can have permission to post some quotes from the -1 here. It's really conclusive about a subject like this. All I can say is for Yo-Yo to please re-read the Stall & Departure sections in the A-10 TO -1

 

Yes, the wing drops in the stall. Correct or not, it was a very docile drop! A Cessna 172 will drop the wing faster, if flown a little uncoordinated.

I'd say the stall characteristics of the Hog is very benign. Now, it may very well be that it should have even better stall characteristics. That I don't know. But I wouldn't say it's hard to control it in high AoA flight. Rudder was very responsive, for instance.

 

Well, this docile drop can screw up your egressing and threat evasion. Also dogfights. They will stop you from pulling more or sustaining a high AoA turn limiting you to less than optimum turns.

 

The wing drops can get very aggressive, they're not always benign like in your test, and even if it doesn't it still is not a correct or realistic behaviour as per the videos I shared earlier (I bid you to watch all of them, at the specific time marks especially), and many more I can still share if needed, and the document(s). Even without those references, I would highly doubt a military aircraft designed to be aerodynamically abused would have the stall characteristics of a civil training prop plane (and a great one at that, but just can't get compared to such high performance mil jets).

[Goblin]

I'm not saying stall behaviour of the A-10C is correct in DCS...

 

A slip angle is the angle of the relative airflow and the longitudinal axis of the aircraft, and as such has nothing to do with deflection of flightcontrols other than deflection of flight controls will induce a slip. Did that make sense..? :)

 

Pitching up, without rolling... Even if you could do this perfectly, with no roll input, you may still have crossed controls, so that the ailerons are deflected ever so slightly. This can be enough to trigger assymetric wing stall on most aircraft. Assymetric loadout or fuel imbalance can also contribute to this.

 

I mentioned the C172 because that one is also said to be almost impossible to spin. It's not! ;)

 

I have flown aircraft that will throw themselves over on their backs, in a heartbeat, if stalled assymetrically. So I'll still think the stall behaviour of the simulated A-10C in DCS is easy to handle. But, it might need a slight tune-up of the SAS.

[SCU]

I'm not saying stall behaviour of the A-10C is correct in DCS...

 

A slip angle is the angle of the relative airflow and the longitudinal axis of the aircraft, and as such has nothing to do with deflection of flightcontrols other than deflection of flight controls will induce a slip. Did that make sense..? :)

 

I understand that, and it does make sense. I only meant that 20° of slip is quite a big angle.

 

Pitching up, without rolling... Even if you could do this perfectly, with no roll input, you may still have crossed controls, so that the ailerons are deflected ever so slightly. This can be enough to trigger assymetric wing stall on most aircraft. Assymetric loadout or fuel imbalance can also contribute to this.

 

I mentioned the C172 because that one is also said to be almost impossible to spin. It's not! ;)

 

I have flown aircraft that will throw themselves over on their backs, in a heartbeat, if stalled assymetrically. So I'll still think the stall behaviour of the simulated A-10C in DCS is easy to handle. But, it might need a slight tune-up of the SAS.

 

I know you've stated that you're not saying that this is correct in DCS, but you're also sort of implying that I should accept that fact and deal with it. Even if it's docile and easy to handle it still needs to be fixed, and for me I think I shouldn't have to "handle" this, easy or not, since the real guys don't have to either.

 

And as I understand it, you have flown only civilian aircrafts. While I have the deepest respect for every kind of aircraft pilot but no offense buddy, military aircraft are a whole different beast. They are designed to be pushed to and over the edge of their envelope a lot.

[Goblin]

Well, I have flown the Cessna 172, SAAB Safari, Grob 115, Fokker 50 and DHC8, which all have been used in military versions ;) But I know what you mean, not flown fighters.

There's nothing magical about fighter aircraft aerodynamics though...

 

But, no, that's not what I meant... Thought I made it clear, but I'll try again :)

 

I think the stall behaviour needs to be tweaked slightly. I don't think that much needs to be altered, and maybe it will be enough to increase the yaw stability some.

 

They are designed to be pushed to and over the edge of their envelope a lot.

 

Actually, this contradicts many of your arguments.

Fighters are usually designed with relaxed static and dynamic stability, in order to be agile. Some even with instability requiring computerized fly-by-wire systems to be stable.

This can lead to unexpected behaviour when transgressing the boundaries of the performance envelope.

Edited August 28, 2016 by Goblin

[SCU]

Well, I have flown the Cessna 172, SAAB Safari, Grob 115, Fokker 50 and DHC8, which all have been used in military versions ;) But I know what you mean, not flown fighters.

There's nothing magical about fighter aircraft aerodynamics though...

 

But, no, that's not what I meant... Thought I made it clear, but I'll try again :)

 

I think the stall behaviour needs to be tweaked slightly. I don't think that much needs to be altered, and maybe it will be enough to increase the yaw stability some.

 

 

 

Actually, this contradicts many of your arguments.

Fighters are usually designed with relaxed static and dynamic stability, in order to be agile. Some even with instability requiring computerized fly-by-wire systems to be stable.

This can lead to unexpected behaviour when transgressing the boundaries of the performance envelope.

 

Well, I won't argue a lot with someone with actual experience and knowledge in the field as opposed to myself. You had mentioned a tweak for the SAS, I never thought the stalling problem could be related in anyway to the SAS so that's why I got the idea you weren't for fixing the issue I'm talking about. However I've always felt the aileron-rudder interconnect, which IIRC is part of the SAS, is very weak in DCS's A-10 when banking at slow to medium airspeeds, where (after stopping roll) the jet wobbles about the yaw axis and therefore the roll axis as well. But I didn't read any data about this matter so I have nothing to say if this is realistic behaviour or not.

 

I'm lead to believe that fighters do go (close) to the edge of their envelope most of the time and that's still considered safe operation for the jet cause that's how it was designed. Okay it may have been overzealous of me to say "over the edge of the envelope" but you get my idea.. I guess.

[Goblin]

Hey, your meaning counts as much as mine! I don't know it's a stability problem, as I have no idea how the flightmodel is coded.

[SCU]

Same here, I was hoping someone who coded this aircraft can shed some light on this. All I know is what I read in the -1 and what I see in the HUD recordings and videos contradicts what happens in the game.

[Pocket Sized]

(There's an A-10A dash 1 that's free to view but can't be downloaded. Would posting a link to it be frowned upon?)

 

It mentions that the veeeery edge of the chopped tone is absolute max performance. So if you're turning hard and hear it flickering between the two that's a good indication you're squeezing the wing for all it's got. It also means that holding the chopped tone doesn't necessarily mean you're stalling.

 

HOWEVER we can't confirm if what we have is accurate unless somebody finds a video of an A-10 wildly rocking it's wings due to a stall.

[SCU]

Yep, it's supposed to be that post chopped stall tone you're just not getting any extra lift, you even start losing it when the airflow starts separating as far as I understand it. The A-10 does have wings dropping according to the -1, but only in certain situations which are not present when it happens in the sim. As far as what we have in the sim, so far every video I've seen and every thing I have read in the -1 contradicts what's modeled right now.

 

If only a developer of this sim can shed some light on this issue, if that's how it was intended to be and why? Or if it was actually a bug/mistake.. We all make mistakes so I'm not being critical here, I just want the inaccuracies to be fixed when they're discovered.

[SCU]

Ahem.

I guess this section of the forum isn't very popular.

 

Anyway, I believe it would be more realistic ED to just remove the wings dropping behaviour at high AoA. I have no clue how hard or easy that would be, I imagine it isn't that simple but it should be done, unless I'm wrong. But I think the evidence I've provided is enough and the TO -1 just agrees with them. I'd also appreciate it if I know YoYo's thoughts on this?

 

Of course at a later time you can work with the stall modelling to be realistic in accordance with the flight manual.

[bkthunder]

Ahem.

I guess this section of the forum isn't very popular.

 

 

 

Don't worry, this is the standard behaviour when you raise any questions around here. It was discussed before along with other issues that I won't bother to mention. Bottom line is: if you want to discuss these things, I suggest you try a different forum.

[SCU]

Don't worry, this is the standard behaviour when you raise any questions around here. It was discussed before along with other issues that I won't bother to mention. Bottom line is: if you want to discuss these things, I suggest you try a different forum.

 

ًWell I don't look for a discussion for the sake of discussion, it's just that the popularity of a suggestion increases the chance of a change mostly, especially if this suggestion, if implemented, will make the sim more realistic.

 

I thought of starting this thread in the main A-10C Forum but I figured it would get moved here anyway so I started it here.

[SCU]

Yo-Yo is a busy guy, if anything comes of this it will be updated here

 

So has anything come of this? Please don't forget about this problem, if it's fixed it's gonna make A-10 much more realistic and better for everyone I'm sure.

I don't wanna sound desperate, but it's gotten so quiet here.

[NineLine]

So has anything come of this? Please don't forget about this problem, if it's fixed it's gonna make A-10 much more realistic and better for everyone I'm sure.

I don't wanna sound desperate, but it's gotten so quiet here.

 

The quote you used pretty much stands I think.

[SCU]

The quote you used pretty much stands I think.

 

I understand how busy someone like YoYo is. But not getting as much as a comment from any of the A-10C's developers for almost a month now? This a serious issue & it's quite a shame it has gone unfixed for 5 years now (?)..

 

I've provided evidence for my claim. If i'm proven wrong then so be it, but I can't be proven wrong when the devs won't even reply to me :music_whistling:.

[probad]

I can't be proven wrong when the devs won't even reply to me :music_whistling:.

what kind of twisted logic is this

[SCU]

what kind of twisted logic is this

Was this the only part you read off my post?

 

Sent from my cell phone using Tapatalk.

[Raistlen007]

I as well would like to know what the developers feel about this issue. The stall behavior definitely impairs enjoyment of the module to some extent.

 

Even an acknowledgement that they won't be looking into it because of internal priorities is a valid and honest response.

[SCU]

Even an acknowledgement that they won't be looking into it because of internal priorities is a valid and honest response.

 

Exactly my point :thumbup:. Although I hope that wouldn't be their response, it'd be better if they just put it in the lower priority list. IMHO this should be high priority but oh well, it's rare to get any major update to an old module :cry:.

[GGTharos]

Nothing is physically stopping you from flying an airbus close to the edge of the envelope or right to it ... but why on earth would you, other than for testing characteristics before it is delivered to customers? You just fly it within the safe limits because anything else is just poor judgement.

 

You fly fighters to the limit when and if you have to, because sometimes you simply must: the other guy competing against you will do that, too. It's a different level of training and skill ... not a different set of aircraft physics.

You fly a fighter quite benignly and nowhere near the 'edge of the envelope' when you don't have to. Risk reduction ;)

 

I'm lead to believe that fighters do go (close) to the edge of their envelope most of the time and that's still considered safe operation for the jet cause that's how it was designed. Okay it may have been overzealous of me to say "over the edge of the envelope" but you get my idea.. I guess.

[SCU]

You fly fighters to the limit when and if you have to, because sometimes you simply must: the other guy competing against you will do that, too. It's a different level of training and skill ... not a different set of aircraft physics.

You fly a fighter quite benignly and nowhere near the 'edge of the envelope' when you don't have to. Risk reduction ;)

 

That's quite true actually.

But the point of this thread is what actually happens when you do take the A-10 to/close to its limits; it isn't the same as what happens in DCS's A-10.

 

As a matter of fact, as far as I gather, the point where you get chopped stall warning is still not at the very edge of the envelope.

All those publicaly available recordings have a lot of chopped tone riding, let alone the unpublished flights, which may show how often this sort of maneuver is practiced in reality.

 

Point is, pulling the jet into chopped warning tone & even slightly pulling more ---> wing drop shouldn't happen. Other behaviour should happen like buffeting, but lets just get past the initial issue.