KA-50 changes after latest patch

[bingbean]

O.K. Raptor9. I fix it. 

[Dantagonistic]

20 hours ago, bingbean said:

R E C A P I T U L A T I O N:

1. Green skval TV

Etc

Good summary. Don't forget English cockpit is showing Russian warning lights. I was reading through some KA-50 bug reports recently and some of the testers reported some fixes in the (now released?) update, but no mention in the changelog.

Edited November 17, 2022 by Dantagonistic

[QuiGon]

On 11/16/2022 at 11:47 PM, bingbean said:

R E C A P I T U L A T I O N:

1. Green skval TV

ED statement : IRL features

My opinion: Don't care too much, but i don't found any footages where the shkval TV have green image. There is lots of photos of turn off shkval where it looks green, but that is common features of old B&W TV , that they are look green while they are turn off, however the turn on image is B&W.

2. up to 2 second ATGM trigger delay 

ED statement : Added delay up to 2 seconds for ATGM Vikhr launch sequence by original flight manual notes.

My opinion: I don't know where those notes came from after 13 years of Ka-50 development in DCS and how relevant they are. Personally, it doesn't make much sense for me to have such a long delay. I'm slowly getting used to it.

3. ABRIS map refresh rate 1 per second so the zoomed map moves jerkily.

ED statement : IRL features , but it broke the speed indicator what is actually harder to fix at it looks like.

My opinion: Do we really need such as "improvement". So should I expect that after 2, 4 or 10 years someone in ED will think that automatic map switching in the Mi-24P is not realistic and so they will "improve" it by removing this feature?

4. Almost all the time shake

ED statement : none

Some additional info:

 

My opinion: I have no problem driving kart , but looking on helmet go-pro kart video make me sick. Flying Ka-50 make me sick now same way.  It's different to sit in something that shakes and shake with it than to just look at something that shakes. So i am pray for camera cockpit shake set up slider for Ka-50 in special options.

5. HDG HOLD - is not accurate as before. Heli breaks left or right but doesn't hold the correct heading

ED statement :  I do not find none yet

Community research: 

 

My opinion: Magnetic heading mode is WIP and dont works as is intended. I am really interesting for ED statements.

6. Shkval performance degraded and some new cockpit textures looks blurry.

ED statement : (Beta tester) New DCS lighting and new Ka-50 cockpit doesn't work corect together.  Workaround for now : turn off the "Cockpit Global Illumination", this makes the difference in the skhval.

My opinion: I have no idea what the option "Cockpit Global Illumination" do. Some modules looks little bit better when it is turn on (F-15 for example), some looks  same for me (MI-24P) no matter if it is on or off.  Significant difference is only in Ka-50.

7. KH-25ml Misslle Not Tracking the laser

ED statement : this is correct as is. See manual page 94:

My opinion: I prefer vikhr, but good to know.

 

My overall opinion:  it looks like a nice downgrade.

 

 

8. ABRIS doesn't work without GNSS anymore.

Edited November 18, 2022 by QuiGon

[okopanja]

On 11/16/2022 at 11:59 PM, Raptor9 said:

Just to be clear, that was not an official "ED statement" as too whether or not the effect is correct or not. That was me (as someone with real-world helicopter experience), responding to Volk's comment in clarifying that Transverse Flow Effect, rather than Effective Translational Lift, is the aerodynamic effect that generates a shudder effect in rotorcraft at lower airspeeds.

I am not on the Black Shark dev team, or any dev team actually, nor have I ever flown a real Ka-50. I was simply provided aerodynamic context, so please don't misconstrue or use my comments as official statements regarding the DCS Black Shark.

Thanks for the really good explanation on difference in these terms, but there is one more thing here. It occurred to me that the Ka-50 is coaxial rotor helicopter, which means one set of blades would generate this effect in usual direction, but other one should generate this in opposing direction. As a helicopter pilot, what would you expect?

[FusRoPotato]

Yes, 3 bladed contra-rotating blades have a very elegant geometry of forces that nearly cancel each other out completely, except in one mode (z-direction). I put about 8 years into wind and water tunnel research on the effects of contra-rotating blades with variable geometry and separation in extreme sideslip conditions. We've even tested configurations nearly identical to the Ka-50's, though much smaller. The inertia, gyroscopic procession, torque, phase lag shift vibration modes, and p-factors are essentially flat or canceled compared to a single rotor, so long as the rotors have 3 or more blades. The question I mostly looked into was, to what degree of diameter and collective variation patterns produce vibrations, noise, and performance/efficiency costs. The magnitude of total vibration is about 95% less in the worst cases, typically when the upper rotor has a smaller diameter than the bottom or the separation is excessive. The type of vibrations caused by those factors are usually out of phase, not completely destructive (destructive phase is good), and usually reside in the pitch direction. However, they are hard to measure because of how small they become.

The vibration we are seeing in the DCS Ka-50 is what you expect from a single rotor because of the speed regimen it shows up at. It's typically jarring because the vibration is angular. In a contra-rotating configuration, those angular vibrations are destructive. On the other hand, the translational vibrations due to phase lag are small but additive. In addition to that, there are also Z-bound vibrations arriving from blade-passing. This would usually not be a problem, maybe hardly even noticeable because the lift variation to inertia ratio is ridiculously small. However, if you have some structural bending modes (tail or pylon) or wing-mounted weapon somewhere that offers a harmonic response, it could grow and become quite noticeable. It's a very small up and down vibration that is more-so continuous across a higher range of speeds.

The flight model of the Ka-50 in DCS feels invented. I assume it either came without experience, or it was copy/pasted from a single rotor and roughly hacked to fit. That sounds reasonable to expect when it comes to simulators because that's just a really common thing that happens. I suspect the latter because of how the Ka-50 banks at higher speeds, or pitches when trying to make a tight yaw at speed. These again are another set of effects you'd only expect with a single rotor. 

I was really disappointed in the flight behaviors when I got this module. I'm hoping we will see some improvements in the BS3. Please continue modifying it to completion. A Ka-50 without a close approximation to its flight model is like a Raptor without stealth, or Hornet without a hook, or a Tomcat without a radar.

Edited November 19, 2022 by FusRoPotato

[Hobel]

vor 1 Stunde schrieb FusRoPotato:

Yes, 3 bladed contra-rotating blades have a very elegant geometry of forces that nearly cancel each other out completely, except in one mode (z-direction). I put about 8 years into wind and water tunnel research on the effects of contra-rotating blades with variable geometry and separation in extreme sideslip conditions. We've even tested configurations nearly identical to the Ka-50's, though much smaller. The inertia, gyroscopic procession, torque, phase lag shift vibration modes, and p-factors are essentially flat or canceled compared to a single rotor, so long as the rotors have 3 or more blades. The question I mostly looked into was, to what degree of diameter and collective variation patterns produce vibrations, noise, and performance/efficiency costs. The magnitude of total vibration is about 95% less in the worst cases, typically when the upper rotor has a smaller diameter than the bottom or the separation is excessive. The type of vibrations caused by those factors are usually out of phase, not completely destructive (destructive phase is good), and usually reside in the pitch direction. However, they are hard to measure because of how small they become.

The vibration we are seeing in the DCS Ka-50 is what you expect from a single rotor because of the speed regimen it shows up at. It's typically jarring because the vibration is angular. In a contra-rotating configuration, those angular vibrations are destructive. On the other hand, the translational vibrations due to phase lag are small but additive. In addition to that, there are also Z-bound vibrations arriving from blade-passing. This would usually not be a problem, maybe hardly even noticeable because the lift variation to inertia ratio is ridiculously small. However, if you have some structural bending modes (tail or pylon) or wing-mounted weapon somewhere that offers a harmonic response, it could grow and become quite noticeable. It's a very small up and down vibration that is more-so continuous across a higher range of speeds.

The flight model of the Ka-50 in DCS feels invented. I assume it either came without experience, or it was copy/pasted from a single rotor and roughly hacked to fit. That sounds reasonable to expect when it comes to simulators because that's just a really common thing that happens. I suspect the latter because of how the Ka-50 banks at higher speeds, or pitches when trying to make a tight yaw at speed. These again are another set of effects you'd only expect with a single rotor. 

I was really disappointed in the flight behaviors when I got this module. I'm hoping we will see some improvements in the BS3. Please continue modifying it to completion. A Ka-50 without a close approximation to its flight model is like a Raptor without stealth, or Hornet without a hook, or a Tomcat without a radar.

 

One thing about the vibration and please correct me if I'm confusing things.

there are some video recordings from inside and outside of the KA-52 where you can already observe a lot of virbrations that we now have ingame.
When I look at irl recordings of the Apache, the whole thing is much quieter.

[FusRoPotato]

The vibrations generated are small, but if they are harmonically absorbed by the tail or pylons, they could absolutely shake like crazy.

The thing is, harmonic modes are dependent on RPM and the structural properties of the pylons and the weight they carry. They have to match quite closely. Any change in RPM or weight of pylons could inhibit that vibration completely. This can vary a lot between models of helicopter. If it is present on the Ka-52, it might be present on the Ka-50 for a specific loadout/RPM, but is it? It may be a very similar aircraft, but it doesn't take much difference to avoid harmonics.

What I do know is that these vibrations won't only be present at slow speeds beyond zero. They will be present at most all speeds, including hover and cruise, until RPM is changed or weight is dropped. The behavior of a helicopter shaking as it comes to a stop, or starts moving from a stop, is characteristic of a single rotor due to a phase shift during transition through transverse flow. It is a roll and yaw shake that contra rotating blades cancel out and turn into a z-shake that's far less noticeable.

After doing some digging into those videos you suggest, it does look like they are overloading poorly maintained aircraft. 

[okopanja]

25 minutes ago, FusRoPotato said:

After doing some digging into those videos you suggest, it does look like they are overloading poorly maintained aircraft. 

I do not doubt that there are some of these effect, but videos do not show them at low speed for Ka-50. We did see some of them having vibrations and high speed but this could be due to the load out at high speeds and/or poor maintenance. I am just wondering why ED keeps adding this at 60-70 km/h, when we could not find any video that actually shows this. I wish they could share more on what they based their decision.