[UNABLE TO REPRODUCE]Ka-50 Banking Right Bug!

[randomTOTEN]

someone take a snapshot of the mi-8 at 220kph level cruise.

Seems very well balanced for 220kph.. that must be the design cruise speed.

 

 

BTW, the newest lighting engine updates make the fans look fantastic!

[Tippis]

That's exactly how my control indicator looks in S&L trimmed forward flight. Little bit of left stick and right pedal.

 

 

I'm okay with this never being "fixed."

The thing is, for me (and others) this isn't trimmed for forward flight — it's trimmed for level flight, but with a significant amount of left side-slip. And not just as in “you started with slip, and you haven't cancelled it out” but as in, in order to move forward and fly levelled at the same time, you must by necessity also glide left, and the only way to cancel that out is to be in a constant counter-roll right, otherwise your lateral thrust vector will not point be zeroed out.

 

There is a constant sideways force coming from somewhere — and that leaves you with one of two choices: tilted forward flight or level forward-left flight. Cancelling out the side movement and then trimming for level flight makes the side slip return. Similarly, kicking in a bit pedal to point the nose in the direction of travel only ends up changing the direction of travel — the side-slip is still there.

 

It is still possible to get into a level hover, but that again requires left stick (but not necessarily any right pedal) and that only works if you do it manually. Engaging the hover AP will somehow put the helo in a level attitude that constantly slip left (and again not just in the usual kind of pendulum movement around a reasonably-fixed point on the ground, but as in varying left-slip — the variation is still there, but is added on top of a leftwards movement).

 

…but not always. I've had it behave the way it always has, but something triggers that extra sideways force at some point.

[Quadg]

Seems very well balanced for 220kph.. that must be the design cruise speed.

 

 

BTW, the newest lighting engine updates make the fans look fantastic!

 

that is quite a difference.

 

i wonder if the ka-50 is trimmed for hover instead of cruise? to assist the 90's AI autopilot?

 

edit: reading tippis post, it does not sound like it.

Edited March 16, 2020 by Quadg

[randomTOTEN]

The thing is, for me (and others) this isn't trimmed for forward flight — it's trimmed for level flight, but with a significant amount of left side-slip.

Not true, and apparently I need to describe the acronym S&L, which means "Straight and Level."

The helicopter is maintaining a constant heading, has no bank, is in coordinated flight with no sideslip (the airplanes direction through the air= the direction it is pointing). Any drift over the ground is due to the wind only, and it's certainly possible in the KA-50 right now, even when taking control of the tracks posted in the OP.

 

 

Use your rudder, that's one of the reasons it exists! Yes, I understand the dual rotor system should cancel our torque, but apparently right now rudder correction is required, and as soon as you put it in, this "problem" disappears....

 

 

Also I just realized my "rudder trimmer" is INOP in the KA-50. Can somebody else please check this?

[Quadg]

it does explain why mi-8 pilots may experience right roll :)

they are not using enough pedal and stick.

when they move to the ka-50

[randomTOTEN]

But Mi-8 pilots should be extremely accustomed to using cyclic, pedals, and constant trimming to control a helicopter. Especially with large and sometimes opposite control and trim directions when transitioning through different flight phases.

They should feel like the Ka-50 is incredibly easy, and not notice any drifting whatsoever (because they unknowingly corrected for it immediately on liftoff).

 

 

Now.. fixed wing tricycle wheel jet pilots with lazy feet... :lol::lol::music_whistling:

[Quadg]

But Mi-8 pilots should be extremely accustomed to using cyclic, pedals, and constant trimming to control a helicopter. Especially with large and sometimes opposite control and trim directions when transitioning through different flight phases.

They should feel like the Ka-50 is incredibly easy, and not notice any drifting whatsoever (because they unknowingly corrected for it immediately on liftoff).

 

 

Now.. fixed wing tricycle wheel jet pilots with lazy feet... :lol::lol::music_whistling:

 

try the huey :)

 

you dont trim it, you twitch in time to its gyrations. to fly it smooth and level.

[randomTOTEN]

I should have said,

 

 

...fixed wing tricycle wheel jet pilots with lazy feet, that don't even know how to trim a load asymmetry, or after flaps extension, or for airspeed changes, even with FBW....

...you should see some of the Viper and Hornet threads man. We'll get these new guys squared away soon enough!

[Tippis]

Not true

No. That's the whole point. It is true — hence why it's an issue: it shouldn't be true, but it is.

 

And you don't need to describe anything because we know what it means, but we're saying that for some reason, when this behaviour strikes, the Ka-50 isn't capable of straight and level flight. It's capable of straight flight or level flight, but not both. Except occasionally it is, which just makes it more annoying to track down.

 

Use your rudder, that's one of the reasons it exists! Yes, I understand the dual rotor system should cancel our torque, but apparently right now rudder correction is required, and as soon as you put it in, this "problem" disappears.

No. Again, that's the problem: using the rudder in an attempt to cancel out the torque and have the thing travel nose-wards doesn't make the problem go away — it just changes the direction of the side-slip.

 

It's not that rudder correction is required, but that the correction fails to correct anything for some odd reason (or, rather, it corrects things, but not the sideways movement). That's what makes it so mind-boggling: it's something that shouldn't even be possible (without wind) and yet it happens. There is a ghost input that pushes the helo leftwards that is unrelated to cyclic or torque input. :joystick:

 

 

That said, I'm almost beginning to think that maybe this is an art issue after all: that it's the ADI (and possibly control indicator, although that seems even more unlikely) that is misaligned somehow.

[randomTOTEN]

It's capable of straight flight or level flight, but not both.

Nobody in this thread has posted an example of this being the case.

 

 

 

It's very obvious that S&L flight cannot be maintained with the cyclic centered, but that's why the entire trim system exists. You don't have to keep the cyclic centered. The system is designed for comfortable sustained flight with the cyclic trimmed in any position.

 

 

In all posted examples the cyclic and rudders are centered. The helicopter wanders in a predicable pattern. It is out of trim.

 

 

using the rudder in an attempt to cancel out the torque

This statement makes no sense. The entire purpose of the rudder is to cancel out torque. That's how the rudder works. In fact it's not even called a rudder, they are "anti-torque" pedals. The entire system works through the principle of differential torque between the rotors. How can you say that this control should not be used to cancel out the very principle it uses to function? :music_whistling:

 

 

have the thing travel nose-wards doesn't make the problem go away — it just changes the direction of the side-slip.

changes it to be in the direction of the helicopters travel... i.e. coordinated flight. That's it's job, and proper operation of the helicopter.

 

 

There is a ghost input that pushes the helo leftwards that is unrelated to cyclic or torque input.

Yes, it's a "ghost input" of right cyclic, and a little left pedal. And you're incorrect here, it yaws the helicopters nose to the left, and adds a right horizontal component of rotor lift, resulting in a right sideslip. In both tracks and the video posted the helicopter sideslips right, which translates into a right uncoordinated turn.. not a left one.

 

 

 

The corrective action is a dead horse we shall beat again, add left cyclic and right pedal. Activate trim to relieve control pressure. Problem goes away. Helicopter flies straight and true, coordinated flight. Fly the helicopter, stop letting it take you for a ride.

Edited March 16, 2020 by randomTOTEN

[Tippis]

It's very obvious that S&L flight cannot be maintained with the cyclic centered, but that's why the entire trim system exists.

And that's not the issue. The issue is that, when trimmed for S&L flight, you don't get S&L flight.

 

To wit: guess which of these two yields S&L and which one yields sideslip.

 

This statement makes no sense.

That's kind of the point. When used for the very purpose the pedals exist, they don't yield the result that they should — instead, the result is one that shouldn't even be possible. Hence why we're in the “bug and problems” section of the forum. :thumbup:

 

How can you say that this control should not be used to cancel out the very principle it uses to function?

Oh, the answer to that is quite simple: I didn't actually say anything of the kind.

 

changes it to be in the direction of the helicopters travel

…except it doesn't. That's kind of the whole problem, as has been explained over and over and over by now. Using the pedals to try to take out the apparent torque does indeed change the direction of the helicopter's travel, but it does not actually get rid of the unwanted yaw — it just rotates the whole wonky system and the nose is still not aligned with the direction of travel.

 

Well, unless you ignore the instruments and just go by sight.

Perhaps some clarification is needed since this is apparently so difficult to grasp: it's not that it's impossible to get into S&L flight, but that to do that, you have to set the helo up in an indicated attitude that isn't S&L flight. Conversely, if you set up an indicated S&L flight, you won't get one — you get straight or level, but not both. This is why I'm starting to suspect that part of this is indeed an art issue (but there are still some AP behaviours that don't quite fit with that).

 

And you're incorrect here

No. You're just skipping over what I'm saying: that with left cyclic and right pedal, in a setup that should yield straight and level flight — you get left sideslip.

 

What you're saying is what should happen; what I'm saying is what does happen. Again, this is why we're in the “bugs and problems” section. If you're not seeing the behaviour, then good for you, but that just means your input isn't particularly useful — especially not when your suggestions of how to fix things are actually the things that are being done, but which aren't working as they should. And you can skip the poorly disguised remarks about flying ability — that just shows you're not actually reading what's being said to you and just making hasty assumptions based on what you think is being said. See, for instance, the assumption that I said you shouldn't use your pedals.

Edited March 17, 2020 by Tippis

[Murey2]

And that's not the issue. The issue is that, when trimmed for S&L flight, you don't get S&L flight.

 

To wit: guess which of these two yields S&L and which one yields sideslip.

 

That's kind of the point. When used for the very purpose the pedals exist, they don't yield the result that they should — instead, the result is one that shouldn't even be possible. Hence why we're in the “bug and problems” section of the forum. :thumbup:

 

 

Oh, the answer to that is quite simple: I didn't actually say anything of the kind.

 

…except it doesn't. That's kind of the whole problem, as has been explained over and over and over by now. Using the pedals to try to take out the apparent torque does indeed change the direction of the helicopter's travel, but it does not actually get rid of the unwanted yaw — it just rotates the whole wonky system and the nose is still not aligned with the direction of travel.

 

Well, unless you ignore the instruments and just go by sight.

Perhaps some clarification is needed since this is apparently so difficult to grasp: it's not that it's impossible to get into S&L flight, but that to do that, you have to set the helo up in an indicated attitude that isn't S&L flight. Conversely, if you set up an indicated S&L flight, you won't get one — you get straight or level, but not both. This is why I'm starting to suspect that part of this is indeed an art issue (but there are still some AP behaviours that don't quite fit with that).

 

No. You're just skipping over what I'm saying: that with left cyclic and right pedal, in a setup that should yield straight and level flight — you get left sideslip.

 

What you're saying is what should happen; what I'm saying is what does happen. Again, this is why we're in the “bugs and problems” section. If you're not seeing the behaviour, then good for you, but that just means your input isn't particularly useful — especially not when your suggestions of how to fix things are actually the things that are being done, but which aren't working as they should. And you can skip the poorly disguised remarks about flying ability — that just shows you're not actually reading what's being said to you and just making hasty assumptions based on what you think is being said. See, for instance, the assumption that I said you shouldn't use your pedals.

 

 

Why do you think that the ka-50 should fly like a traditional helicopter?! Because it shouldn't!

[Tippis]

Why do you think that the ka-50 should fly like a traditional helicopter?!!

Simple: I don't.

[fudabidu]

To abbreviate things:

 

Can anyone provide a track or video showing the Ka-50 NOT banking to the right with increasing airspeed? Please show the briefing for wind settings and include the in-game control indicator.

 

I didn't believe it either, but I tested it and it's there. It's not like I suddenly forgot how to fly this thing.

[Murey2]

To abbreviate things:

 

Can anyone provide a track or video showing the Ka-50 NOT banking to the right with increasing airspeed? Please show the briefing for wind settings and include the in-game control indicator.

 

I didn't believe it either, but I tested it and it's there. It's not like I suddenly forgot how to fly this thing.

 

 

+1 :thumbup:

 

 

That's exactly the issue here! I fly the Ka-50 almost daily!!! All of the sudden I started seeing that weird behavior that I describe it as if you're compensating for traditional helicopter's main rotor torque! That started with the Shkval lights fix after that update I started to find my self in fight with the beast to fly it, and it's not flying as I used to fly it!

 

 

Something have changed in the flight model and I'm dead sure about it!!!

 

 

Anyway I have watched many videos of the Ka-32 vids. on the net and it's flying way better than the Ka-50 that is flown by 1 combat pilot, not to mention that the Ka-32 doesn't have the AP that is in the KA-50!!!!!! So, you can IMAGINE now!

 

 

Check for your self below:

 

https://www.youtube.com/watch?v=BoKKXtBgpqE

[Lt_RAzOr_957]

@Murey2

Sir i tried it all coldstart hotstart asymetric toys low fuel 100% fuel rotor anti ice on rotor anti ice off -> and everyhting is just fine get the fXXX rid of your controls indicator and calm down everythings gonna be ok.

 

------------------

 

I know mate its not easy for you but it almost Looks ike your build is different from mine, indeed your steam Version but yah :D should be the same Right ?

 

Satire included

[Baaz]

I have always noticed the slight bank to the right since the first day I flown the Ka-50 many, many, moons ago.

 

I always attributed it to the fact that the gun is on the right side, adding weight and drag.

 

Not an expert, but it makes sense to me.

[randomTOTEN]

I was going to provide a track file but somehow it's always the same track of a single player mission I played weeks ago. Maybe I shouldn't launch the mission from the ME? Might try again later.

 

Reproducing is really easy (empty mission, no wind, hot start):

Just fly straight and level at around 100kph and watch the controls indicator. You'll see a bit of left trim is required.

Now trim the nose down to -15° without moving the X-axis. As you accelerate the helicopter will start banking right.

 

Same thing also works in reverse:

Trim for straight and level flight at 200kph and pull up to decelerate. As speed decreases the helicopter will start banking left.

 

It's rather obvious if you watch the angle difference between aircraft datum and pitch ladder.

This is exactly my experience as well, and I consider this the best description. Not "magic rudder that doesn't work," but a progressing right roll and slight left yaw with acceleration. It's easily trimmed, but it does exist.

 

 

Here's what the Flight Manual mentions about coaxial rotor designs.

 

 

Aerodynamic symmetry of the coaxial configuration is provided by the lack of reactive moment on the airframe and the relatively close upper and lower rotors and their beneficial mutual effect. This results in little thrust difference when balanced. Balance is provided by the rotors' side forces directed in different directions as they balance each other with their lateral movement. This emerges due to their separation being insignificant.

...Thanks to the lack of the tail rotor, the coaxial-rotor helicopter is not subject to the constant effect of the alternate side force. The coaxial design ensures a smooth combination of efficient control and aerodynamic damping, which provides good controllability.

...Owing to aerodynamic symmetry, a coaxial-rotor helicopter has literally no correlation between longitudinal and lateral movement. For example: in a single rotor helicopter, changing collective results in changing directional trim by the tail rotor; this affect is absent with a coaxial system. However, it has independent control and is easy to master by any pilot irrespective of their flying skills. The lack of flight mode variables and yaw movement and side forces on the airframe, combined with the lack of a relation between the power changes (collective pitch) and directional and lateral control, improves a coaxial helicopter's stability and controllability. Due to this, flight safety is enhanced and flying in extreme conditions is easier. This is especially true regarding low-altitude flying, small landing pads, broken terrain, high barometric altitudes, and system failures. Controlling a coaxial-rotor helicopter is as simple as flying a docile training aircraft. At the same time, stability, controllability and maneuverability are equal to, if not better, than single-rotor helicopters.

 

 

DCS BS2 Flight Manual EN.pdf 68-69

 

 

I originally thought this was a "rigging" problem, but hover tests show that it's a function of airspeed (doesn't exist in a hover), and thus can't be a static displacement of the control system, it's a dynamic effect.. perhaps aerodynamic? But the manual says these aerodynamic effects shouldn't affect the helicopter.

 

It's certainly a bug then, but not a super critical one.. annoying for sure.:book:

[Tippis]

get the fXXX rid of your controls indicator and calm down everythings gonna be ok.

Riiiight… Getting rid of the thing that indicates that there is a problem doesn't actually make the problem go away, you know. :lol:

[Baaz]

This is exactly my experience as well, and I consider this the best description. Not "magic rudder that doesn't work," but a progressing right roll and slight left yaw with acceleration. It's easily trimmed, but it does exist.

 

 

Here's what the Flight Manual mentions about coaxial rotor designs.

 

 

 

 

 

I originally thought this was a "rigging" problem, but hover tests show that it's a function of airspeed (doesn't exist in a hover), and thus can't be a static displacement of the control system, it's a dynamic effect.. perhaps aerodynamic? But the manual says these aerodynamic effects shouldn't affect the helicopter.

 

It's certainly a bug then, but not a super critical one.. annoying for sure.:book:

 

 

"Aerodynamic symmetry of the coaxial configuration is provided by the lack of reactive moment on the airframe and the relatively close upper and lower rotors and their beneficial mutual effect. This results in little thrust difference when balanced. Balance is provided by the rotors' side forces directed in different directions as they balance each other with their lateral movement. This emerges due to their separation being insignificant.

...Thanks to the lack of the tail rotor, the coaxial-rotor helicopter is not subject to the constant effect of the alternate side force. The coaxial design ensures a smooth combination of efficient control and aerodynamic damping, which provides good controllability."

 

This statement applies to any coaxial configuration, and not specifically just Ka-50.

 

Taking that into consideration, one must realize that the Ka-50 from the start is not a balanced aircraft, but will always be heavier on the right because of the additional weight of the gun. Add in the additional drag caused by the gun when in forward flight, it's easy to see that the Ka-50 will have a tendency to lean right.

 

Again, I'm no expert, but it's easy to see (at least for me) what's happening here. It's been present from day one when I started flying this bird over 5 years ago. I don't see any difference in it's performance now, and can't see what all the excitement is about.

[Tippis]

Again, I'm no expert, but it's easy to see (at least for me) what's happening here. It's been present from day one when I started flying this bird over 5 years ago. I don't see any difference in it's performance now, and can't see what all the excitement is about.

The excitement is over a difference in its performance now compared to how it behaved in 2.5.5. It didn't used to behave in the way some of us are seeing. The fact that some aren't seeing it just makes it more exciting… and annoying to hunt down since it means that comparisons of what works and what doesn't aren't nearly as useful in narrowing the issue down.

 

 

It's especially noteworthy that it's inconsistent and intermittent for individual users — I'm seeing both the same flying behaviour it has always had one second, and the next, the side-slip / roll behaviour appears for no apparent reason. It's hardly surprising that it is just as intermittent, or more, between different users.

Edited March 18, 2020 by Tippis

[randomTOTEN]

The additional drag makes sense, but the additional weight argument doesn't from my perspective.

The weight of the gun doesn't changed based on airspeed, and the equal amount of left cyclic would be needed to cause an equal increase in lift on the right side of both rotor discs.

Of course increased drag would cause a right yaw with increasing airspeed. I can see that, but that would result in mostly yaw to the right (left sideslip) requiring left pedal as speed increases... wouldn't it?

 

 

It's an interesting idea though.

[randomTOTEN]

It didn't used to behave in the way some of us are seeing.

You got any evidence for this claim?

[Tippis]

You got any evidence for this claim?

See above posts.

 

 

I'd also offer this description from the manual (page 6-17):

12.

Yaw indicator

. Indicating the yaw of the aircraft, this indicator displays a ball in a liquid filled tube. If there is no yaw in the flight path, the ball will be centered. If there is yaw, the ball will be displayed in the opposite direction of yaw. The sideslip indication ball moves by local acceleration so it will not always display the actual sideslip. This depends much on the type of maneuver you are flying.

When this bug strikes, pretty much all of that goes out the window: it stays centred when there is an accelerating side-slip; it stays off-center when flying straight and level. As discussed in both this and the accompanying thread, there are very apparent connections between the roll issue and the uncommanded side-slip issue.

Edited March 18, 2020 by Tippis

[Baaz]

The additional drag makes sense, but the additional weight argument doesn't from my perspective.

The weight of the gun doesn't changed based on airspeed, and the equal amount of left cyclic would be needed to cause an equal increase in lift on the right side of both rotor discs.

Of course increased drag would cause a right yaw with increasing airspeed. I can see that, but that would result in mostly yaw to the right (left sideslip) requiring left pedal as speed increases... wouldn't it?

 

 

It's an interesting idea though.

 

You're right, the weight of the gun doesn't change, but will always be present. Thus requiring a little left trim to counter the weight, just like we have to do on any aircraft with an asymetrical loadout. With any fixed wing, do we trim rudder to counter this? No. We trim for wings level.