Jump to content

FM-sideslips and drag


birdstrike

Recommended Posts

scratching my head on this one for a while already.

 

my friends and i tested a couple of times already in the ww2 aircraft the influence of "sideslips" and the drag that comes with it, or better is expected to come with it...

 

now, when stepping into the rudder completely and cross controls, you will notice a reduction in speed obviously, so its not a question as to whether drag is modeled or not.

 

but the amount of lost speed seems a bit on the low end? in the 109 it even accelerates with completely crossed control when in a medium dive with throttle on idle.

 

but whats really interesting is that when flying with the same planes next to each other in formation, same fuel amount, same engine settings, it doesnt seem to matter at all, if flying coordinated or not. now im not talking about the extremes here, i.e. fully crossed controls, but one flying coordinated with the ball centered, and the other not. normally i would expect the one flying coordinated to get like 5-10kn, or at least noticeable, more out of the aircraft than the one who doesnt. but there is no difference at all noticeable.

 

so to which extend is this modeled in dcs?

 

EDIT:

the further i test this, the more dissappointing this gets...flying level full power, you can in either of the ww2 birds fly in a slipped attitude, with the slip ball, or in case of the spit the needle, shifted at least half way to either side of the tube of the gauge, and even more, without losing a single knot in flight. i turned on the info bar and switched to TAS. flew for a couple of minutes in either of the aircraft on deck above the water and get the same dissappointing result in all of them. i really thought dcs is more detailed in this regard. :huh:


Edited by birdstrike
Link to comment
Share on other sites

The question is, all of that, compared with what?

 

 

 

If you're comparing with other sims just through the other sims away, they don't and I mean DON'T model drag and gain/drain of speed correctly whatsoever, never did, ever.

 

 

If you compare to something you've flown IRL, you should know how different all those aspects are in every model. In my experience a C152 is a thing while C172RG a whole different world with regards to drag and speed drain for instance while they should be similar aeroplanes just one heavier than the other, even sharing a similar wing type and profile.

 

 

I can clearly tell in the sim a Spitfire slips in a very different way than 109 for instance, so you mean that compared to what?

 

 

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

EDIT:

the further i test this, the more dissappointing this gets...flying level full power, you can in either of the ww2 birds fly in a slipped attitude, with the slip ball, or in case of the spit the needle, shifted at least half way to either side of the tube of the gauge, and even more, without losing a single knot in flight. i turned on the info bar and switched to TAS. flew for a couple of minutes in either of the aircraft on deck above the water and get the same dissappointing result in all of them. i really thought dcs is more detailed in this regard. :huh:

Although far from a scientific method or description, it may seems you're flying in simple mode instead of full simulator? There are options in the configuration for casual flyers.

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

sure the different types slip differently. thats not the problem here. its that even with a "medium" slip, you dont lose energy whatsoever, but can achieve top speeds in slipped attitude just like you do when flying perfectly coordinated.

only when you start crossing controls severly, it starts to bleed energy.

 

and no, im not flying in simple mode.


Edited by birdstrike
Link to comment
Share on other sites

No, I don't think you can get top speeds flying sideslipping, you can't even straight and level if you don't trim and fly the correct settings.

 

 

Anyway, you seem to compare to something you want to get and these aircraft fly like RL aircraft do, so don't expect them to behave like anything you've flown in any simulator before.

 

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

No, I don't think you can get top speeds flying sideslipping, you can't even straight and level if you don't trim and fly the correct settings.

 

 

Anyway, you seem to compare to something you want to get and these aircraft fly like RL aircraft do, so don't expect them to behave like anything you've flown in any simulator before.

 

 

S!

 

trimming the aircraft as stable as possible will indeed get u slightly faster. thats not the topic here.

with same trim settings, power settings, fuel and ammunition settings, slight to medium slips dont have any impact...not noticeable at least visible when flying in formation with another player slipping on purpose while the other flies coordinated, nor in singleplayer with the info bar open observering the TAS. u will achieve the same top speed and maintain it. in my opening post i already said that i tested this with a couple of friends together, and now u suggest im flying in arcade mode. then u suggest i want this sim to behave like another arcade game?

 

i dont expect the aircraft in dcs to behave like in other simulations. thats why i fly dcs in the first place. i expect them to behave and show real life behaviour as close as possible.


Edited by birdstrike
Link to comment
Share on other sites

i dont expect the aircraft in dcs to behave like in other simulations. thats why i fly dcs in the first place. i expect them to behave and show real life behaviour.
And they do.

 

 

It's not like from time to time something doesn't get broken in DCS, it happens, but if it is you should go to the specific model forum and ask about it. Is it you realised this now or it happens now but not before? Then something maybe really broken obviously. It is for all the models the same or model specific? Are you in Open Beta or release? All that matters, a post saying "I think this should be like that instead of this" says few.

 

 

 

Or, was it something you expected to get but it's no happening the way you thought? You've to understand many people come to complain based on their previous experience in simulation because it wasn't what they expected to have, but this is a hardcore simulation and yes, real aeroplanes doesn't behave the way most people think they do.

 

 

Yes, you can keep slipping in an aircraft the same speed (bit less, but just a bit) you were before, aerobatics do all the time. No top speed, you can't fly in formation at top speed to start with and top speed is achieved under a certain conditions. Yes if you sideslip to land it bleeds airspeed and altitude, but in order to lose speed you've to keep the nose somewhat high, if you dive it won't lose speed it'll gain speed indeed. Try sideslipping idle and keeping your altitude, watch the horizon and altimeter, it's not that easy and the time you start to lose altitude it seems you aren't loosing any speed. And it happens like that IRL, yes, I wouldn't tell if that description is DCS or my flying lessons back then.

 

 

 

S!


Edited by Ala13_ManOWar

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

please reread my opening post. pretty much all your questions are covered in there.

 

you cant fly fomration at top speed

 

interesting as we do this all the time online.

 

Yes, you can keep slipping in an aircraft the same speed (bit less, but just a bit)

 

and in dcs its not a bit less, it makes no difference, up until you start to really cross controls. being lazy on the rudder doesnt have any negative impact. and thats my concern.

 

if you dive it won't lose speed it'll gain speed indeed

 

and no, it doesnt need to gain airspeed with sideslipping in real life. that completely depends on the type you fly. several types i fly do the exact opposite. they will bleed plenty of speed as soon as you cross controls even if you dive.(well im not speaking of a vertical dive here). and they already lose noticeable speed when not focusing on keeping the ball in center


Edited by birdstrike
Link to comment
Share on other sites

It doesn't matter if its a 109 or a Cessna or a B-52, flying uncoordinated means more drag, and unless you change your power setting, or your attitude that means less speed. It doesn't make sense that you can fly in formation with one person flying with the ball in the middle, and the other with the ball off to the side and they both are equally fast.

9./JG27

 

"If you can't hit anything, it's because you suck. If you get shot down, it's because you suck. You and me, we know we suck, and that makes it ok." - Worst person in all of DCS

 

"In the end, which will never come, we will all be satisifed... we must fight them on forum, we will fight them on reddit..." - Dunravin

Link to comment
Share on other sites

please reread my opening post. pretty much all your questions are covered in there.
Then please reread my post again. Any further info we can test by ourselves or something?

 

 

It's not like from time to time something doesn't get broken in DCS, it happens, but if it is you should go to the specific model forum and ask about it. Is it you realised this now or it happens now but not before? Then something maybe really broken obviously. It is for all the models the same or model specific? Are you in Open Beta or release? All that matters, a post saying "I think this should be like that instead of this" says few.

 

 

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

What speed reference(s) are you using ?

 

Beware that with the exeption, I believe. of the Spitfire, the ASIs in DCS do not ( yet ) model pitot errors due to sideslip.

 

In a real aircraft a sideslip will introduce "dramatic" reading errors and show a much lower IAS than the actual aircraft speed ( TAS ).

 

My experience with DCS was - I have to check if anything changed in between … - that indeed sideslips had a plausible impact on aircraft performance, not only flight dynamics wise but even systems wise ( like the effects o radiators efficiency in the P51d ). Maybe something changed ?

 

I'll check it at home ASAP and report back.

Flight Simulation is the Virtual Materialization of a Dream...

Link to comment
Share on other sites

interesting as we do this all the time online.
In order to achieve top speed you have to keep straight and level a certain time with the aircraft perfectly trimmed and in good atmospheric conditions. So still I don't think you fly perfect formation @top speed :music_whistling:. I've flown years of Virtual aerobatics and formation flying and no, I think you're mistaking concepts here, sorry.

 

 

… and in dcs its not a bit less, it makes no difference, up until you start to really cross controls. being lazy on the rudder doesnt have any negative impact. and thats my concern.
DCS does model control surfaces drag according to deflection, I think it makes a difference even if it's not the one you believe. In my experience IRL it's the same with low controls deflection, trimming indeed means low control permanent deflection and it helps with higher speeds lowering drag, not the opposite. So again, I think you're mistaking concepts here.

 

 

… and no, it doesnt need to gain airspeed with sideslipping in real life. that completely depends on the type you fly. several types i fly do the exact opposite. they will bleed plenty of speed as soon as you cross controls even if you dive.(well im not speaking of a vertical dive here). and they already lose noticeable speed when not focusing on keeping the ball in center
It doesn't need, but it can if you don't watch the horizon, tell my former instructor :lol: . DCS warbirds do sideslip, bleed energy and increase variometer drop very nicely, of course in a different way depending on the model. If you don't mean a recent change in a latter version that shouldn't be there they do and very realistically I have to say.

 

 

So again, if you don't have any further and better information and it's only your feeling I don't thing we can help with that more than explaining the already explained as it works as they're supposed to do.

 

 

S!


Edited by Ala13_ManOWar

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

Just came out of testing, Yak-52, Bf109, P51d and Spitfire, using RAlt-Y to see TAS in F2 view, and while trying to maintain V/s after entering sideslip they all consistently dropped it.

 

 

Looks like it's OK, at least on my version ( latest Open beta ).

Flight Simulation is the Virtual Materialization of a Dream...

Link to comment
Share on other sites

In order to achieve top speed you have to keep straight and level a certain time with the aircraft perfectly trimmed and in good atmospheric conditions. So still I don't think you fly perfect formation @top speed :music_whistling:. I've flown years of Virtual aerobatics and formation flying and no, I think you're mistaking concepts here, sorry.

again, thats not the topic here...you can try and twist the topic and insist on your trimmed out top speed...once more for you: at the same trim, fuel and power settings, we couldnt notice any difference flying a several minutes next to each other, with the one flying coordinated, and the other not...this is repeatable, and we have done it plenty of times. it doesnt matter at all, if both aircraft are trimmed out perfectly, or not trimmed out at all, as long as they have the exact same trim settings...your trimmed out top speed is irrelevant to this topic. trimming is not the topic here, except for some reason you keep bringing this up, while nobody is questioning the effects of it in dcs here.

 

DCS does model control surfaces drag according to deflection, I think it makes a difference even if it's not the one you believe. In my experience IRL it's the same with low controls deflection, trimming indeed means low control permanent deflection and it helps with higher speeds lowering drag, not the opposite. So again, I think you're mistaking concepts here.

control surfaces drag...again, reread my OP, as that was pretty much the first thing i said.

fuselage drag though i doubt it tbh hence the issue we experience i guess.

its not me mistaking concepts, but you mistaking the topic here as you still keep talking about trim states.

 

It doesn't need, but it can if you don't watch the horizon, tell my former instructor :lol: . DCS warbirds does sideslip, bleed energy and increase variometer drop very nicely, of course in a different way depending on the model. If you don't mean a recent change in a latter version that shouldn't be there they do and very realistically I have to say.

reread my posts. pronounced sideslips with crossed controls will cause drag.slight to medium slips, i.e. flying straight with the feet off the pedals, having the ball somewhere to the right or left, dont. i said this repeatedly beginning in my OP. the rest is off topic.

 

 

So again, if you don't have any further and better information and it's only your feeling I don't thing we can help with that more than explaining the already explained as it works as they're supposed to do.

 

further and better information? i pointed out the issue we experience in detail. there is nohting more to add to it and nobody is stopping you to test it yourself. you cant help anyway, except you are an ED dev responsible for the FM. you can insist and keep arguing that everything is alright and that you feel its perfectly realistic. that doesnt make it true nevertheless.

and once more, reread my previous posts, i already told you that i also tested this with a couple a friends online. so its not only my feeling. to further observe it, i addionally tried it offline with the info bar open showing TAS.


Edited by birdstrike
Link to comment
Share on other sites

further and better information? i pointed out the issue we experience in detail. there is nohting more to add to it and nobody is stopping you to test it yourself. you cant help anyway, except you are an ED dev responsible for the FM. you can insist and keep arguing that everything is alright and that you feel its perfectly realistic. that doesnt make it true nevertheless.

and once more, reread my previous posts, i already told you that i also tested this with a couple a friends online. so its not only my feeling. to further observe it, i addionally tried it offline with the info bar open showing TAS.

Mate, yeah, further information, we still don't know which aircraft you talk about, is it all of them? If that's the case then I hardly doubt your "feeling", just saying but remember host mission settings (including realism options) are the ones used for everybody online, many things could happen. Is it in stable or Open Beta version? Did it happen before or is a new thing? In which mission/map/weather conditions does it happen? you know the kind of further information that's expected in order to try to be helpful :thumbup: .

 

 

 

again, thats not the topic here...you can try and twist the topic and insist on your trimmed out top speed...once more for you: at the same trim, fuel and power settings, we couldnt notice any difference flying a several minutes next to each other, with the one flying coordinated, and the other not...this is repeatable, and we have done it plenty of times. it doesnt matter at all, if both aircraft are trimmed out perfectly, or not trimmed out at all, as long as they have the exact same trim settings...your trimmed out top speed is irrelevant to this topic. trimming is not the topic here, except for some reason you keep bringing this up, while nobody is questioning the effects of it in dcs here.
As said, lower deflections aren't increasing the drag like you think to believe. Put the ball to one full side and see if you can still keep formation with exact same power, though nobody knows in which aircraft to the date.

 

 

control surfaces drag...again, reread my OP, as that was pretty much the first thing i said.

fuselage drag though i doubt it tbh hence the issue we experience i guess.

its not me mistaking concepts, but you mistaking the topic here as you still keep talking about trim states.

No, still you mistaking concepts as you keep to believe RL aircraft have to fly the way you say they do. Fuselage drag isn't your problem in-flight, control and lift surfaces are the ones making the huge drag here (not to mention a huge propeller in front of you), lower deflection/low AoA/lower torque equals lower drag and viceversa. Further statements are yours only.

 

further and better information? i pointed out the issue we experience in detail. there is nohting more to add to it and nobody is stopping you to test it yourself. you cant help anyway, except you are an ED dev responsible for the FM. you can insist and keep arguing that everything is alright and that you feel its perfectly realistic. that doesnt make it true nevertheless.

and once more, reread my previous posts, i already told you that i also tested this with a couple a friends online. so its not only my feeling. to further observe it, i addionally tried it offline with the info bar open showing TAS.

No, you pointed out YOUR feelings and we don't even know yet in which aircraft or under which conditions. I already explained a few things and how they work and if you don't say it's a broken thing since the last version I don't have to test anything as I perfectly know how DCS warbirds perform. Sorry if you think I missed the target, but I don't understand why you don't tell us what on Earth were you flying :huh: .

 

 

Please understand, if you have something to say about a broken feature in recent versions fine, it can be tested. But if you say it happens in every warbird in DCS since ever and you just happen to come now (and not since 2012 P-51 was first released... :doh:) to say they are wrong… Sorry mate but they are perfectly fine and the problem is in your (wrong) feelings. So please search for a better explain (with details) of something that is really happening or it's simply not :thumbup: .

 

 

 

S!


Edited by Ala13_ManOWar

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

Link to comment
Share on other sites

try to actually read :)

 

DCS is a great title but it certainly isn't the end all/be all of flight modeling. There are poorly modeled aspects especially in the prop driven straight wing airplanes.

 

You are not going to get much traction on these boards trying to convince the fan boys the FM's are not perfect simulations of the real thing. They have too much wrapped up in the whole "this is EXACTLY like the real thing" wackiness to admit imperfection.

 

It is unlikely form drag during a side slip is correctly modeled. There would be no data. The title started as a jet sim and, in general, you don't slip a jet. I doubt anyone on the development team has any clear idea of the differences between flying a high performance piston engine aircraft and a swept wing jet. That is not their fault. It takes a few thousand hours at the controls of multiple types covering straight and swept wing, prop and jet to have the experience to properly discern the idiosyncrasies. Few have that breadth of experience.

 

The props fly like jets, especially when it comes to aspects of the flight model that relate to uncoordinated flight, the effect of engine torque, slipstream effects and stall behavior. That is unlikely to change from the reactions I have seen on this board.

 

You are best served understanding the limitations of the FM and deciding if you can live with them.

 

 

 

 

EDsignaturefleet.jpg

Link to comment
Share on other sites

  • ED Team
DCS is a great title but it certainly isn't the end all/be all of flight modeling. There are poorly modeled aspects especially in the prop driven straight wing airplanes.

 

You are not going to get much traction on these boards trying to convince the fan boys the FM's are not perfect simulations of the real thing. They have too much wrapped up in the whole "this is EXACTLY like the real thing" wackiness to admit imperfection.

 

It is unlikely form drag during a side slip is correctly modeled. There would be no data. The title started as a jet sim and, in general, you don't slip a jet. I doubt anyone on the development team has any clear idea of the differences between flying a high performance piston engine aircraft and a swept wing jet. That is not their fault. It takes a few thousand hours at the controls of multiple types covering straight and swept wing, prop and jet to have the experience to properly discern the idiosyncrasies. Few have that breadth of experience.

 

The props fly like jets, especially when it comes to aspects of the flight model that relate to uncoordinated flight, the effect of engine torque, slipstream effects and stall behavior. That is unlikely to change from the reactions I have seen on this board.

 

You are best served understanding the limitations of the FM and deciding if you can live with them.

 

What kind of prop driven aircraft effects DCS models poorly for your mind?

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

Link to comment
Share on other sites

  • ED Team
Dynamical stall and spin are somwhere off in DCS prop planes. These kites are just too easy comparing to RL situations.

 

https://forums.eagle.ru/showthread.php?t=223403

 

Please take in mind that in RL your controls very often go to the pro-spin position and the pilot has to appply significant forces even to neutralise them. In DCS you just have to get your hands off the controls to do it. :)

 

By the way, the Mosquito spin example is nothing about the DCS conditions: this plane had one engine stopped during the maneuver, so it has very strong unrecoverable sideslip as it stalls due to lost of thrust and ascending maneuver.

Cobra got a progressive stall because of low altitude and pilot's attempts to recover dive. IOne can see it in MP very often :).

 

And finally, for example, one of the distinctive features of the Mustang accelerated stall is its ability to self recover after a snap roll (from one of the reports I have). And it's exactly the same you can see in DCS.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

Link to comment
Share on other sites

Yo-Yo will all respect for Your work

 

 

 

Problem with DCS is that You could really rape 109 or Fw 190 even sometimes P-51 on Your controls where IRL Your plane would be stall and spin like the hell. Such spin in low alt means mostly dead.

 

I tried rellly horiible things expecially in D-9 and K-4 and there is no afraid of such things.

 

 

These videos which i posted show that real planes could got spin even without violenty and brutal controls actions - just only some pilot errors or engine failure ( not brutal actions at all).

 

Thats why DCS prop planes fell for me as a real pilot that are flying too easy and too forgiving way in many sitautions where IRL probably most of such actions would be mean deadly spin ( at low alt).

Link to comment
Share on other sites

  • ED Team

I think you overestimate the spin possibility for some fighters...

 

Anton as a predecessor of Dora and it was possible (as Erich Brunotte tells me) to make a snap rol in 190A from a turn to the opposite turn that is a kind of pre-spin movement (post-stall AoA and autorotation).

He also said that he never got in a spin in fighters accidentally.

 

And as an example of extremely spin-proof aircraft:

1529739880_P-47spin.jpg.4092ce865b7eca9c7df993228d551ec3.jpg

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...