Impossible to fly for anyone else?

[steve65]

I have been following the discussion in this thread and it has me a little concerned(i haven't flown dcs in a while and want to try my hand at the sukhoi until the mig-29 gets its PFM)about flying the sukhoi.i have been hearing that it is very touchy with stick inputs so I went on YouTube and watched the many videos on the Su-27(wings of Russia videos are excellent) and a lot of them show the cockpit view while in flight and the Russian pilot seems to be moving the stick quite a bit for the plane being "twitchy" IMO.now there are a lot of factors we don't see in the video,airspeed of the plane,thrust settings,pilot ability etc. let me say I'm no expert on FCS systems nor am I an engineer,so can some of our very knowledgable members tell me why would the real life pilot move the stick more than what some are saying are cm on their flight sim equipment.now remember I did not go college and study flight dynamics or some other highly technical field so if you put it in lay mans terms i would appreciate it.

[Svend_Dellepude]

As DarkFire said. Make sure your trim is neutral and stick position is not forward of center or you will find yourself in a inverted stall before you know it.

I was actually fighting a guy on the guns'n'roses server the other day who thought it would be a good trick to press 'S' after the merge and pull 20G for a quick turnaround to get his guns on me. It worked a couple of times, but i found my way around him.

[ShuRugal]

I have been following the discussion in this thread and it has me a little concerned(i haven't flown dcs in a while and want to try my hand at the sukhoi until the mig-29 gets its PFM)about flying the sukhoi.i have been hearing that it is very touchy with stick inputs so I went on YouTube and watched the many videos on the Su-27(wings of Russia videos are excellent) and a lot of them show the cockpit view while in flight and the Russian pilot seems to be moving the stick quite a bit for the plane being "twitchy" IMO.now there are a lot of factors we don't see in the video,airspeed of the plane,thrust settings,pilot ability etc. let me say I'm no expert on FCS systems nor am I an engineer,so can some of our very knowledgable members tell me why would the real life pilot move the stick more than what some are saying are cm on their flight sim equipment.now remember I did not go college and study flight dynamics or some other highly technical field so if you put it in lay mans terms i would appreciate it.

 

one thing here that will vary significantly from real life is that the Su-27 ASC has a knob the pilot can adjust (seen below the throttle beside the ASC disable switches) which changes the ratio of stick movement to control-surface movement while ASC is engaged. This gives the real-world pilots the ability to tune their stick response literally on-the-fly.

 

In the game, we have to accomplish the same effect by dropping into the settings menu and adjusting axis curvature.

[steve65]

one thing here that will vary significantly from real life is that the Su-27 ASC has a knob the pilot can adjust (seen below the throttle beside the ASC disable switches) which changes the ratio of stick movement to control-surface movement while ASC is engaged. This gives the real-world pilots the ability to tune their stick response literally on-the-fly.

 

In the game, we have to accomplish the same effect by dropping into the settings menu and adjusting axis curvature.

 

Thanks ShuRugal that helped alot:thumbup:

 

PS: would you have any starting points for the axis curves for the su-27?

Edited May 22, 2015 by steve65

[ShuRugal]

i like to run somewhere between +15 and +30 for both roll and pitch. going over +30 will make the plane very docile around center, but as the stick moves further to the sides, the response will increase at a rate that makes it difficult to hold attitude in sustained maneuvers.

[DarkFire]

As DarkFire said. Make sure your trim is neutral and stick position is not forward of center or you will find yourself in a inverted stall before you know it.

I was actually fighting a guy on the guns'n'roses server the other day who thought it would be a good trick to press 'S' after the merge and pull 20G for a quick turnaround to get his guns on me. It worked a couple of times, but i found my way around him.

 

Yep, that trick surprised the crap out of me the first time I saw it. Some pilots will believe that the ability to carry out UFO-style instant 20-50G turns is an engagement-winner. What they don't seem to realise, at least at first, is exactly how much energy this bleeds away, and the huge dangers in going that far towards the bleeding edge of the flight envelope.

 

I really do think that the only use for disabling the ACS is to carry out the Kobra, which looks cool but probably has very little actual tactical use (debatable, I know). Entering direct control mode doesn't help with stall recovery, makes the aircraft incredibly twitchy in pitch, can easily impose G loads that ought to be instantly fatal for both the airframe and pilot and though it can produce incredibly tight turns, in my opinion the near-total loss of energy which results simply isn't worth it.

 

I don't think I'd really be bothered if ED went back to making the "S" key perform the scripted Kobra and removing the ability to turn off the ACS. OK, OK, I know it's realistic but I think it's largely pointless.

[Ironhand]

...

I don't think I'd really be bothered if ED went back to making the "S" key perform the scripted Kobra and removing the ability to turn off the ACS. OK, OK, I know it's realistic but I think it's largely pointless.

I kind of like having it available (unscripted Cobra). If they'd just add the G-stress penalties, I'd be even happier.

[steve65]

i like to run somewhere between +15 and +30 for both roll and pitch. going over +30 will make the plane very docile around center, but as the stick moves further to the sides, the response will increase at a rate that makes it difficult to hold attitude in sustained maneuvers.

 

Thanks for the advice I will try that when I get time to fly the flanker.:thumbup:

[Fri13]

 

I don't think I'd really be bothered if ED went back to making the "S" key perform the scripted Kobra and removing the ability to turn off the ACS. OK, OK, I know it's realistic but I think it's largely pointless.

 

The Cobra maneuver is very useful, but it is just one maneuvers among others, not a silver bullet.

 

There are three kinds of people:

A: claiming it has little or no benefits in a dog fight and always point out that energy reservation is best choice regardless of situation (or suddenly situations change to 2 vs 1 etc)

 

B: claiming it has a lot benefits and try to use it as often they can, even when there is other better choices, giving just examples to A by doing stupid things.

 

C: understands it has many great benefits but it is like a Cannon in BVR, you are happy you have it when suddenly you are merged with the enemy and you know you have a wider range of maneuvers to solve situation when or if it comes to that.

 

The Cobra maneuver or AoA exploiting same benefits is like HMS and IRTS or a datalink between planes and missiles or a vectored thrust nozzles. They are not always needed, not always the best choice and when there comes situation it is giving benefit.... It can be the tool to get the victory.

 

I dislike it is a single key push to disable all, unlike it should be. (Based the previous thread about how it should work and what switches does what) Limiting player possibilities.

[Svend_Dellepude]

If your cobra maneuver fails to kill the bad guy you have no options left other than spending the next many seconds trying to recover the airspeed you just lost, which means you have to point the nose down.

If you are already on the deck, well...

[Drona]

If your cobra maneuver fails to kill the bad guy you have no options left other than spending the next many seconds trying to recover the airspeed you just lost, which means you have to point the nose down.

If you are already on the deck, well...

 

The cobra is a last ditch maneuver and used only when there is no other option available. I'd rather attempt the cobra and try to turn the tables on my pursuer than just wait for the inevitable. Also, the cobra should be used only when the opponent least expects it...;)

[Svend_Dellepude]

The cobra is a last ditch maneuver and used only when there is no other option available. I'd rather attempt the cobra and try to turn the tables on my pursuer than just wait for the inevitable. Also, the cobra should be used only when the opponent least expects it...;)

 

Which would it be? Last ditch or when he least expect it.

But you are right with the first one. Instead of just ejecting, you can try the cobra and then pull the handle.

BTW if you find yourself in a situation in a SU-27 vs F-15, where your last call is to pull of a stunt maneuver you probably did many things wrong leading up to that. ;)

[GGTharos]

It should be neither. People put this on their HOTAS but guess what... That's not where it is in RL, because direct control is there for emergencies. I hope yaw from asymmetry starts affecting this - I wouldn't be surprised if asymmetric loading our any yaw while doing this would quickly develop into a spin.

[Drona]

What I mean is you have to get the timing right...its last ditch but if you don't wait for the right moment, you still die.

 

And yes, if you are in the situation you mentioned, you have done many things wrong and probably deserve to die..but there are times when all your wingmen are dead and you are left with probably a couple bandits on your tail, the cobra could possibly help take out at least one guy with you before you go down.

[rami80]

It should be neither. People put this on their HOTAS but guess what... That's not where it is in RL, because direct control is there for emergencies. I hope yaw from asymmetry starts affecting this - I wouldn't be surprised if asymmetric loading our any yaw while doing this would quickly develop into a spin.

 

Could you elaborate? Asymmetry resulting from what exactly?

[Mr Whippy]

i like to run somewhere between +15 and +30 for both roll and pitch. going over +30 will make the plane very docile around center, but as the stick moves further to the sides, the response will increase at a rate that makes it difficult to hold attitude in sustained maneuvers.

 

I just decided to 'upgrade' to FC3 in DCS and I'm finding the SU27 a bit of a pain to fly too.

 

 

 

What seems to be missing is what you mention.

 

It's all very well to adjust curves for the controller, but this is processed at all speeds and flight conditions, and that just isn't appropriate.

It's entirely reasonable to say that the SU27 probably has a lot of calibration tables that have curve adjustments based on all kinds of inputs, so the controls always feel 'just right' at all times. Curves based on AOA, g force, speed, etc etc.

 

 

Yes you can fly around it, but why would you? Why wouldn't you design the FBW to do all the hard work?

From almost everything I've heard and read about this aircraft, it's meant to be a pleasure to fly. Easy to get the best from it, not hard to get the best from it.

 

Why wouldn't you design the stability control and FBW systems to offer the best of all worlds? Why design a stability system that is leaving you still able to do really wrong things, when you could program it not to?

 

I can see that with the correct approach you can get stunning performance, but why make it so hard to access, needing perfectly balanced inputs, when you have total control over desired input from the pilot, and can figure out from that, the desired output... as if taking away the risks of the unstable design, but adding the benefits of it.

 

 

 

Does anyone know how the current DCS/FC3 stability control system works?

 

I've looked in the data folders but can't see anything specific about the stability control vs other aircraft without it.

I'd assume it'd use a bunch of calibration tables somewhere?

 

 

Cheers

 

Dave

[ruddy122]

The Su-27 modeled in DCS is about finesse and purposeful yet methodical movements.

 

If you are flying the Flanker to the edge of the stall and hold it you will lose control instantly.

 

If dogfighting at low to medium altitude 5000-6000m try to avoid hard maneuvering below 350 Km/hr. The plane will bleed speed quickly and you will lose control a whole lot faster. If you get below 350 km/h ease back on the stick to get the AOA down before you lose control.

 

Also you need to trim, yes the real Su-27 is FBW but in this version you need to trim and trim agressively.

 

Lastly it takes practice but it will soon become one of your best aircraft in the DCS fleet.

 

Hope this helps.

[Mr Whippy]

Yeah I think flying around the problems are somewhat reasonable to do. Kinda fun sometimes too.

A lot of what makes the SU27 great is it's instability, and if you overly control it's pitching then it's losing what makes it great.

 

 

But there is a point currently where you get so much AOA dialled in, and the feedback loop takes you all the way to a total loss of airspeed and control. Once you hit that point, which is easy to hit without being cautious, then it's too late.

I honestly can't see any purpose for that, and if you want it, that is what the stability off switch is for.

 

With stability control on, I'd assume the aircraft wouldn't let you get unstable to the point of being dead in the air.

It's not really stability control otherwise, it's anti-death by insta-g control only :D

 

 

 

 

It'd be interesting to get clarification on the current system. I assume currently inputs just go direct to aircraft outputs, so there is no system looking at inputs and adjusting them based on other variables... except the simple controller curves.

 

Or if there is a properly populated limiter system it'd be interesting to know if it's still a work in progress, or was based on real data or something.

 

 

 

 

 

As for trimming, I'm trying to get it to work. I assume trim to stick on button 4, or whatever it is, lets you set the trim with the joystick once the button is pressed?

 

Or do you just set the level flight with the stick, press the button, and that is set as the trim?

 

 

Either way it doesn't seem to be working for me right now... I think maybe my G25 pedals are confusing things though... hmmm.

 

 

Thanks

 

Dave

[FLANKERATOR]

I seriously doubt the real Flanker departs that easily when the FCS is on. In fact, the fly-by-wire system is supposed to help with the stability at low speeds and high angle of attack. I keep reminding myself that it is still a beta flight model.

[Mr Whippy]

It should be neither. People put this on their HOTAS but guess what... That's not where it is in RL, because direct control is there for emergencies. I hope yaw from asymmetry starts affecting this - I wouldn't be surprised if asymmetric loading our any yaw while doing this would quickly develop into a spin.

 

Good point, when 'direct' control is on, the FBW is probably a raw control system rather than a corrective one.

 

So stuff like asymmetric load while doing a cobra could prove quite interesting.

 

Technically though, if the flight model is 'right' for the SU27, an asymmetric load cobra right now should be as real as it gets!

 

 

I was watching a documentary about the Mig25 yesterday and in early testing when firing missiles, it'd roll upside down and out of control at high altitude due to the sudden CofG movement.

They had some weird automated system to apply corrective roll just after release to 'catch' the aircraft.

 

I bet it's quite amazing how complex the FBW systems are these days to make combat aircraft safe to fly :D

 

Dave

[Mr Whippy]

It should be neither. People put this on their HOTAS but guess what... That's not where it is in RL, because direct control is there for emergencies. I hope yaw from asymmetry starts affecting this - I wouldn't be surprised if asymmetric loading our any yaw while doing this would quickly develop into a spin.

 

I seriously doubt the real Flanker departs that easily when the FCS is on. In fact, the fly-by-wire system is supposed to help with the stability at low speeds and high angle of attack. I keep reminding myself that it is still a beta flight model.

 

Just flying the SU33 and suddenly it does feel quite numb in comparison to the new flight model 27.

 

I can imagine the 27 getting lots better if this is still a beta!

[pepin1234]

ED need to improve this PFM for the Su-27. This is one of several thread talking about the difficulty of control this plane. Very sensitive the blackout for -G, is too much. Also the feeling when we are in close combat is terrible, seem like we are breaking a horse.

[steve65]

I seriously doubt the real Flanker departs that easily when the FCS is on. In fact, the fly-by-wire system is supposed to help with the stability at low speeds and high angle of attack. I keep reminding myself that it is still a beta flight model.

 

^

THIS!!

[GGTharos]

The real bird will 'kick' the stick back at 24 deg AoA. How does one simulate this in the game?

 

Regardless, you can pull through this protective force increase in the RL bird too, and fly yourself exactly into the same problems that virtual pilots do.

 

Just in case you're having doubts, you can find enough videos of Su-27's departing on youtube to prove the point. It is also incredibly unlikely that the FBW was off in those incidents.

 

The problem isn't all in the FM, assuming there is a problem at all. The problem is your expectations and you ability to fly the bird. Certainly the flight sim could do a better job at giving you feedback - if we can't kick the stick, use an audio tone or something else. The real deal might not necessarily have it, but we're missing this very real feedback in other ways.

 

I seriously doubt the real Flanker departs that easily when the FCS is on. In fact, the fly-by-wire system is supposed to help with the stability at low speeds and high angle of attack. I keep reminding myself that it is still a beta flight model.

[GGTharos]

The -g blackout is correct. What might not be correct is the tendency of the aircraft to increase the -g by itself.

 

This is one of several thread talking about the difficulty of control this plane. Very sensitive the blackout for -G, is too much.