correct as-is Anti-Torque pedal rigging since DCS 2.7.18.30348 Open Beta

[Dagobert666]

Since the last OB lease, the tail rotor is no longer at 0 when the pedals are in the central position.

In order to bring it to 0 and thus also the torque of the helicopter to 18%, you have to press the right pedal.
That's why the helicopter turns LEFT around when you're on the ground and you can now take off with almost no left pedal....

The zero point was probably shifted unintentionally.

 

 

Flight Model (FM) since [21.09.2022] DCS 2.7.18.30348 Open Beta.trk

[BIGNEWY]

the team have made a report

thanks

[Raptor9]

The AH-64 tail rotor pedals are rigged in such a way that if they are centered, there is anti-torque thrust being produced. The pedals should be placed so that the right pedal is approximately two inches forward of the left, which will place the tail rotor blades at "flat pitch". This will result in a need to apply right pedal to remove tail rotor thrust when no collective is applied producing torque.

[fapador]

1 minute ago, Raptor9 said:

The AH-64 tail rotor pedals are rigged in such a way that if they are centered, there is anti-torque thrust being produced. The pedals should be placed so that the right pedal is approximately two inches forward of the left, which will place the tail rotor blades at "flat pitch". This will result in a need to apply right pedal to remove tail rotor thrust when no collective is applied producing torque.

The UH-1H tail rotor is also rigged in that way so when going at speeds greater than ~70IAS you need to remove tail rotor thrust by stepping on the right pedal in order to fly straight. 

This behavior doesn't happen in DCS. Just saying..

Apologies for possibly veering of topic but a similar issue is also plaguing the UH-1H module since release.

 

[Raptor9]

3 minutes ago, fapador said:

The UH-1H tail rotor is also rigged in that way so when going at speeds greater than ~70IAS you need to remove tail rotor thrust by stepping on the right pedal in order to fly straight. 

This behavior doesn't happen in DCS. Just saying..

Apologies for possibly veering of topic but a similar issue is also plaguing the UH-1H module since release.

I am not involved with the development of the UH-1, nor do I have any real-world experience with the UH-1. I was only addressing the AH-64 since I can only provide real-world input on that aircraft.

If you believe there is an issue with the UH-1, it will need to be placed in the UH-1 bug report section. But again, I cannot comment on that since it is outside my purview.

[Dagobert666]

1 hour ago, Raptor9 said:

The AH-64 tail rotor pedals are rigged in such a way that if they are centered, there is anti-torque thrust being produced. The pedals should be placed so that the right pedal is approximately two inches forward of the left, which will place the tail rotor blades at "flat pitch". This will result in a need to apply right pedal to remove tail rotor thrust when no collective is applied producing torque.

Hello Raptor9 I'm happy to read from you.
Only so that I understand that correctly:

1- Its not a bug, but is as it should be?
2- Have you flown the AH64 in the current OB patch?
3- Hast you started and landed?

If you can answer all the answers with "Yes", then ok I will just relearn how to fly the Apache.

Thank you very much for your answer

Edited September 22, 2022 by Dagobert666

[Raptor9]

Just did some tests in the OpenBeta to confirm that we were seeing the same behavior.

In the first image, you can see that with the Yaw axis and pedals centered that there is a little bit of positive pitch in the blades, which would produce thrust toward the right, inducing a left yaw of the nose. On the ground with the collective bottomed out, this would also manifest a slight right lean since the tail rotor is mounted high on the vertical tail, creating a slight rotation around the pivot point at the landing gear tires.

In the second image, you can see the pedals are positioned so the right pedal is approximately two inches forward of the left. The tail rotor blades are very close to "flat pitch" where negligible tail rotor thrust would be produced. A good reference point in the Controls Indicator is placing the far left limit of the Yaw channel's SAS white shaded region (yellow arrow) in lined with the vertical red line above it.

When in an IGE hover around 5 feet and torque in the mid-70s, I would expect the left pedal to be maybe a half inch to an inch forward of the right pedal (provided there isn't some other extraneous factors affecting this like crosswinds, poor heading control, or other environmental factors). I would be looking for the vertical red line on the Control Indicator to be somewhere along the outside 50% of the right-sided shaded region (indicated by the yellow bracket and yellow line I drew in this picture).

So to summarize, this is correct behavior and in-line with how the real aircraft pedals would be positioned. As a side note, whenever the BUCS test is completed during real-life run-ups (it's like the F-16 FLCS test or the F-18 FCS BIT), the BUCS test returns the pedals to centered and even with each other like in the 1st image. Prior to starting the engines, I would always ensure the right pedal was forward of the left pedal as seen in the second image. This would ensure the tail rotor was slicing through the air without making any significant yaw motion as the RPMs increased during run-up.

[KeyserSoze62]

7 hours ago, Raptor9 said:

Just did some tests in the OpenBeta to confirm that we were seeing the same behavior.

In the first image, you can see that with the Yaw axis and pedals centered that there is a little bit of positive pitch in the blades, which would produce thrust toward the right, inducing a left yaw of the nose. On the ground with the collective bottomed out, this would also manifest a slight right lean since the tail rotor is mounted high on the vertical tail, creating a slight rotation around the pivot point at the landing gear tires.

In the second image, you can see the pedals are positioned so the right pedal is approximately two inches forward of the left. The tail rotor blades are very close to "flat pitch" where negligible tail rotor thrust would be produced. A good reference point in the Controls Indicator is placing the far left limit of the Yaw channel's SAS white shaded region (yellow arrow) in lined with the vertical red line above it.

When in an IGE hover around 5 feet and torque in the mid-70s, I would expect the left pedal to be maybe a half inch to an inch forward of the right pedal (provided there isn't some other extraneous factors affecting this like crosswinds, poor heading control, or other environmental factors). I would be looking for the vertical red line on the Control Indicator to be somewhere along the outside 50% of the right-sided shaded region (indicated by the yellow bracket and yellow line I drew in this picture).

So to summarize, this is correct behavior and in-line with how the real aircraft pedals would be positioned. As a side note, whenever the BUCS test is completed during real-life run-ups (it's like the F-16 FLCS test or the F-18 FCS BIT), the BUCS test returns the pedals to centered and even with each other like in the 1st image. Prior to starting the engines, I would always ensure the right pedal was forward of the left pedal as seen in the second image. This would ensure the tail rotor was slicing through the air without making any significant yaw motion as the RPMs increased during run-up.

So am I understanding correctly that this is realistic and correct behavior in the real aircraft. However, was this intentional by ED with this patch and what we should expect in the flight model going forward  or is it a bug that introduced this behavior?  Does this also explain the sudden yaw changes from a stable hover that many have already described?

Other than the constant SAS saturated tone in the previous release I was very comfortable in the aircraft but since this change it feels like initial release day. I've been in nice steady hover engaging targets and suddenly it yaws right and the left pedal is totally ineffective to correct. I've also noticed after that happens if I can transition to forward flight and try to get the aircraft back in control the ball is pegged right and no amount of Right pedal brings it back.  Then it will suddenly pop back towards center.

Thanks for all the information you share.

 

[Dagobert666]

8 hours ago, Raptor9 said:

Just did some tests in the OpenBeta to confirm that we were seeing the same behavior.

In the first image, you can see that with the Yaw axis and pedals centered that there is a little bit of positive pitch in the blades, which would produce thrust toward the right, inducing a left yaw of the nose. On the ground with the collective bottomed out, this would also manifest a slight right lean since the tail rotor is mounted high on the vertical tail, creating a slight rotation around the pivot point at the landing gear tires.

In the second image, you can see the pedals are positioned so the right pedal is approximately two inches forward of the left. The tail rotor blades are very close to "flat pitch" where negligible tail rotor thrust would be produced. A good reference point in the Controls Indicator is placing the far left limit of the Yaw channel's SAS white shaded region (yellow arrow) in lined with the vertical red line above it.

When in an IGE hover around 5 feet and torque in the mid-70s, I would expect the left pedal to be maybe a half inch to an inch forward of the right pedal (provided there isn't some other extraneous factors affecting this like crosswinds, poor heading control, or other environmental factors). I would be looking for the vertical red line on the Control Indicator to be somewhere along the outside 50% of the right-sided shaded region (indicated by the yellow bracket and yellow line I drew in this picture).

So to summarize, this is correct behavior and in-line with how the real aircraft pedals would be positioned. As a side note, whenever the BUCS test is completed during real-life run-ups (it's like the F-16 FLCS test or the F-18 FCS BIT), the BUCS test returns the pedals to centered and even with each other like in the 1st image. Prior to starting the engines, I would always ensure the right pedal was forward of the left pedal as seen in the second image. This would ensure the tail rotor was slicing through the air without making any significant yaw motion as the RPMs increased during run-up.

I want to thank you for the really accurate and detailed answer!

So it's an intended change.
All right, then I'll probably have to relearn my muscle memory.
You are doing a great job, keep it up!

I do have one small note though:
You guys really need to write things like this in the patch notes, PLEASE! Otherwise (We) always think it must be a bug.

Edited September 23, 2022 by Dagobert666

[KeyserSoze62]

11 minutes ago, Dagobert666 said:

I want to thank you for the really accurate and detailed answer!

So it's an intended change.
All right, then I'll probably have to relearn my muscle memory.
You are doing a great job, keep it up!

I do have one small note though:
You guys really need to write things like this in the patch notes, PLEASE! Otherwise (We) always think it must be a bug.

 

I'm still not clear it was an intentional change. I appreciate per the Raptor9 explanation that it may represent realistic behavior but  if was an intentional change then as you said how would that big a change not be mentioned in the change logs?  And does it explain the sudden yaw issue others have reported?

 

[csdigitaldesign]

the SAS has gone completely WONKY since the last patch came out. ver. 2.7.18.30348 The patch before we had the constant SAS warnings... sure.. that was annoying.. but it flew well. NOW it's just unflyable.. the SAS keeps teedering back and forth and it's just un-flyable for me. I can't get it to even hold a hover. I tried holding trim reset for 3 seconds but just keeps doing it no matter what. It seems to be effecting the rudder and collective the most. This module has had a ton of issues with this since release... getting a bit tired of it. I know it's early access but hell I'd like to fly the helicopter I paid money for. At least USE IT you know? At the moment it's just not useable.

[munckmb]

If there is something really off, ED will hotfix it. 

[Raptor9]

9 hours ago, KeyserSoze62 said:

I'm still not clear it was an intentional change. I appreciate per the Raptor9 explanation that it may represent realistic behavior but  if was an intentional change then as you said how would that big a change not be mentioned in the change logs?

It was intentional. However, not everything makes it into the changelog unfortunately. When you have something as complex as re-factoring of the flight model and such, it can be quite difficult explaining everything that has been done. Maybe a generic "Flight model adjustments/improvements" should have been included, but the individuals responsible for composing and posting these changelogs to the forums are doing so for all DCS modules.

This is why all of us use these forums in the first place, so we can ask questions to other community members and some of the staff to seek clarification.

9 hours ago, KeyserSoze62 said:

And does it explain the sudden yaw issue others have reported?

This is a separate issue unfortunately. It appears that this is to simulate a "loss of tail rotor effectiveness" (or LTE) effect, specifically as a result of tail rotor vortex ring state. But this is being investigated because it appears to not be working as intended.

[KeyserSoze62]

18 minutes ago, Raptor9 said:

It was intentional. However, not everything makes it into the changelog unfortunately. When you have something as complex as re-factoring of the flight model and such, it can be quite difficult explaining everything that has been done. Maybe a generic "Flight model adjustments/improvements" should have been included, but the individuals responsible for composing and posting these changelogs to the forums are doing so for all DCS modules.

This is why all of us use these forums in the first place, so we can ask questions to other community members and some of the staff to seek clarification.

This is a separate issue unfortunately. It appears that this is to simulate a "loss of tail rotor effectiveness" (or LTE) effect, specifically as a result of tail rotor vortex ring state. But this is being investigated because it appears to not be working as intended.

Excellent and thank you for keeping us informed.

 

[jmoss840]

It's crazy, my Apache fly's as good as ever. But I have seen other people videos of it being uncontrollable. I wonder what the common denominator is? But I have no doubt ED will get it fixed asap. 

 

Edited September 24, 2022 by jmoss840

[Raptor9]

33 minutes ago, jmoss840 said:

But I have been people videos of it being uncontrollable. I wonder what the common denominator is? 

I suspect that it is a combination of factors, with the biggest one I am willing to bet is understanding the force trim system. If the stickied Force Trim thread (31 pages) is any indication, the force trim concept seems to be a misunderstood item for some coming from DCS fixed wing modules and making their initial entry into DCS helos.

Even with those that have experience with other DCS helos, the interactions and behaviors with the AH-64 force trim system is markedly different than other helos in DCS. Not to say that it stands by itself; because each helo has a slightly different control system. The Mi-8 control system is different from the Mi-24's, which are both different from the Ka-50, etc. So when people try to carry over their expectations of how it should feel from other helos, some misunderstandings can occur even within experienced players of DCS helicopters.

There are some analogies that can be made for ease of explanations. I myself have made a lot of them in the past between the AH-64 and the Ka-50. Not because they behave the same as a whole, but certain aspects of the control systems do.

The thing about the force trim in the AH-64, is that the interaction with it not only affects the cyclic and pedals, but also the various layers of FMC/SCAS logic which are further dependent on things such as ground speed, altitude or which sub-mode the hold modes are operating within or whether they are even engaged. The Ka-50 also has many layers of logic/complexity within it's PNK-800 control system, and for years following the release of DCS Black Shark there are still users that post questions to the forum asking for assistance in understanding it.

So the DCS: AH-64D is not unique in this regard. It will take time to learn, especially as the flight controls are refined and improved throughout the early access period. But people need to understand that US Army aviators will receive around 5 months of helicopter flight training before even touching an AH-64, and then go through another 5 to 6 months in learning the AH-64. It's not something you can just pick up and master in a short time span.

Granted, there is some more, better documentation that could be added into the flight maneuvers section of the manual, but this will need to happen over time as well since the manual writer is hard at work updating the F-16 manual for the time being.

[Apache 64]

vor 11 Minuten schrieb Raptor9:

But people need to understand that US Army aviators will receive around 5 months of helicopter flight training before even touching an AH-64, and then go through another 5 to 6 months in learning the AH-64. It's not something you can just pick up and master in a short time span.

100% agreement. 

Caught myself cursing the flight model changes in one of my posts after a few hours of flying.
Slept on it and gave it another chance the next day.
With calm and patience, it gradually went back in the right direction.
In real life the flight model just doesn't change, but in a simulation in early access it does.
After that, it's a case of learning anew every time.
Keep having fun with this wonderful helicopter on its way to perfection.

[Varry007]

I had my rudder/pedal axis inverted on all my modules since forever and a day. So when people say "give some right pedal" i had to give left pedal instead....

So my normal take off in hover is ussually increase torque and push some left pedal to keep the aircraft aligned with its longitudal axis. As my forward motion increases, i decrease the pressure on the left pedal.

 

Now, as a test, i unchecked the invert option on my rudder axis.

 

Theoretically, i should, while doing the usual take off, give right pedal to keep the aircraft aligned; yet, it seems i have to give LEFT pedal, and right as i lift off (i suspect the torque reaches some specific point) i immediately have to give a fair amount of right pedal....

 

It's hard to explain; but it is my impression the pedal axis is bonded to 2 parameters (one setable by the user: the "rudder axis" and one hard coded), which, when the rudder axis is set to "inverted", work together in sync. And when the axis is not inverted, these two parameters counteract each other.

 

It might be something on my end; I won't exclude this; but can someone compare this by setting your rudder axis to invert (beware if your pedal registers 2 axis for 2 device; mine sees axis RZ and Z: only Z is "active" on rudder), if you usually fly without invert checked ON the rudder axis, and see if everything reacts as expected, just inverted; because it is absolutely not the case here.

Edited September 26, 2022 by Varry007

[Swift.]

58 minutes ago, Varry007 said:

I had my rudder/pedal axis inverted on all my modules since forever and a day. So when people say "give some right pedal" i had to give left pedal instead....

So my normal take off in hover is ussually increase torque and push some left pedal to keep the aircraft aligned with its longitudal axis. As my forward motion increases, i decrease the pressure on the left pedal.

 

Now, as a test, i unchecked the invert option on my rudder axis.

 

Theoretically, i should, while doing the usual take off, give right pedal to keep the aircraft aligned; yet, it seems i have to give LEFT pedal, and right as i lift off (i suspect the torque reaches some specific point) i immediately have to give a fair amount of right pedal....

 

It's hard to explain; but it is my impression the pedal axis is bonded to 2 parameters (one setable by the user: the "rudder axis" and one hard coded), which, when the rudder axis is set to "inverted", work together in sync. And when the axis is not inverted, these two parameters counteract each other.

 

It might be something on my end; I won't exclude this; but can someone compare this by setting your rudder axis to invert (beware if your pedal registers 2 axis for 2 device; mine sees axis RZ and Z: only Z is "active" on rudder), if you usually fly without invert checked ON the rudder axis, and see if everything reacts as expected, just inverted; because it is absolutely not the case here.

 

Instead of fiddling around trying to figure out if you should have it inverted or not, just look at what your rudder is doing compared to what the pedals in the cockpit model do...

[Varry007]

51 minutes ago, Swift. said:

Instead of fiddling around trying to figure out if you should have it inverted or not, just look at what your rudder is doing compared to what the pedals in the cockpit model do...

You don’t get it; what i’m saying is; when “invert” is on compared to when it’s off; it doesn’t simply “mirror” the rudders reactions…

[Swift.]

17 minutes ago, Varry007 said:

You don’t get it; what i’m saying is; when “invert” is on compared to when it’s off; it doesn’t simply “mirror” the rudders reactions…

So when you have invert on, and you press your left pedal, the in cockpit left pedal moves forward. And when you dont have invert on, you press the left pedal and the incockpit left pedal moves forwards?

[Floyd1212]

Keep in mind that they shifted the "neutral thrust" point of the pedals "to the right" (assuming your axis aren't inverted) by a couple inches with this last update.  So now the pedal position while lifting the helo lightly off it's wheels is closer to center than it was before. 

Not sure if you saw that in Raptor9's post above with the pictures.

Just wondering if that is throwing off your testing while your axis are inverted from their previous setup.

[Raptor9]

When the SME team (myself included) were evaluating the flight model, the neutral pitch position of the tail rotor was always biased to the right of the yaw axis center. I remember visually confirming this myself while sitting on the ground on the APU and looking at the external view. But I believe with the adjustments to the flight model, the tail rotor thrust was adjusted, which reduced the amount of play in the pedals to achieve the same anti-torque force, and also affected the slight right lean on the ground with the yaw axis at 0.

I'm not 100% sure of that, because there are a lot of factors and variables that are in play regarding the flight model and SCAS system, but that is my assessment of why it's more noticeable now when the trim is reset to 0 in the yaw axis.

[Varry007]

18 hours ago, Swift. said:

So when you have invert on, and you press your left pedal, the in cockpit left pedal moves forward. And when you dont have invert on, you press the left pedal and the incockpit left pedal moves forwards?

@Swift.i rechecked it all by monitoring pedal movement in game while inverted/not inverted; and monitored tail rotor pitch in both scenarios. All seems consistent; so i must conclude the issue lies on my end; seems muscle memory is hard to fight.

Sorry for the false alarm.

[Belphe]

Dear virtual Apache pilots,

1. Spawn in hot at any airport on any of the maps.
2. Make sure all your controls are neutral and the collective is idle.
3. Unlock the parking brakes and the tail wheel.
4. Your sick bags are under the seat..

A few people have raised this issue before but there has been no official reaction by ED so I'd like to hear it, if possible. Are the current tail rotor authority values correctly modelled? Would the Apache spin like this in real life with the idle torque at only 22%?
Many of you are praising the current FM and indeed, some of it's aspects have greatly improved but if this single thing in it is still wrong then the whole model is a dead end.

I know it's WIP. I just want to know that someone sees this problem amid an overwhelming sea of praise and plans to fix it.

Thanks

PS. This post identifies as not being a rant.