DCS: AH-64D Flight Model discussion

[Raven434th]

you say overly dramatic ..I say "direct"

[GrEaSeLiTeNiN]

The Apache to me has strange hover characteristics compared to the other DCS helos. I would describe it as too much momentum (energy) post axis input, not enough damping. Like its large belly mass was not considered for stability. So it rocks back and forth, and sideways like a boat with a very tall sail, drifts and 'capsizes' (rolls) occasionally. Trying to transition from enroute speed into a hover (not those santised IGE hovers) with rudder input to face the desired enemy location, feels at times like this pic.    

Edited April 17, 2023 by GrEaSeLiTeNiN

[Hotdognz]

It certainly flys different from any other DCS helo, only today I was at about 70knots hit right rudder and it put me into a uncontrolled sideways loop that lucky enough I had enough height to pull out from, never done that before and took me totally by surprise

[Agim]

I 100% sure there is some change of handling this helo after last patch. Now it is much more difficult to fly it for me.  I think particular settings of trimming mode in Game Settings play significant role how the pilot feels the difference. What is important for me is if it is bug or "improvement" and I have to get used to it.

[Floyd1212]

I hadn't applied the most recent patch from 4/13/2023 yet, so I thought I would try an experiment...

I recorded a short video with some basic maneuvers around the airfield, then applied the patch, then immediately recorded another video flying the same short exercise again.

Then, just for grins, I tried replaying the track from before the patch back again after I applied the patch. (Spoiler alert: the replay didn't get very far before things got out of hand.)

In general, I felt like the aircraft did behave a little differently upon first pick-up, but nothing major.  Then while performing a 180 degree rudder turn with ATT Hold enabled, it got away from me for a moment, but I was able to get it under control.  That is the only flying I have done since the patch, so it's hard to say what other differences I will notice after flying in a longer "combat" setting, and repeating the same maneuvers I am used to doing over and over.

Note: The first flight does not have a voice-over, then there is one for the second flight, so I'm sorry if I startle you when I start speaking.

 

 

[Belphe]

For me, it feels much more wobbly in the hover and slow speeds. I can still hover fairly easily but getting there is like trying to stay still while being submerged in water. Before the patch cyclic movement would produce instant desired aircraft reaction. Now, I need to counter my cyclic deflection to stop the aircraft movement as going neutral would not suffice (just like in space!). I'm not saying it's incorrect! Just different and it'll take time to get used to.

One other thing I found much more problematic is strafing sideways. The Apache develops awkward roll movements that quickly get out of control even at speeds of 30kts even though it was fairly easy to go sideways at 50kts before. Again, this could be true to the real thing...

Oh and now I need to push the cyclic slightly forward from the centre to stay in hover after a vertical takeoff (that centre of mass shift?).

Edited April 17, 2023 by Belphe

[GremlinIV]

2 hours ago, Floyd1212 said:

I hadn't applied the most recent patch from 4/13/2023 yet, so I thought I would try an experiment...

I recorded a short video with some basic maneuvers around the airfield, then applied the patch, then immediately recorded another video flying the same short exercise again.

Then, just for grins, I tried replaying the track from before the patch back again after I applied the patch. (Spoiler alert: the replay didn't get very far before things got out of hand.)

In general, I felt like the aircraft did behave a little differently upon first pick-up, but nothing major.  Then while performing a 180 degree rudder turn with ATT Hold enabled, it got away from me for a moment, but I was able to get it under control.  That is the only flying I have done since the patch, so it's hard to say what other differences I will notice after flying in a longer "combat" setting, and repeating the same maneuvers I am used to doing over and over.

Note: The first flight does not have a voice-over, then there is one for the second flight, so I'm sorry if I startle you when I start speaking.

 

 

Took watching this to realise what you were doing, with replays and patches etc - then in the last bit the lights came on - yah thats not good...

Regardless of what they have or havent done - i am not convinced it is better or worse than before...

The SCAS pot seems limited and it seems all the axis add to the same pot - so if your in ALT hold flying along nice but close to saturation on the pedals any input from any axis will likely over-saturate and your altitude will start to oscillate, this will affect those close to saturation pedals and into a bank you go, followed by roll and pitch, followed by interaction with the ground in an unpleasant manner. Or at best some unprofessional looking flight.... - coming to a high hover from this flight also gets some odd yaws and oscillations of flight.

Seems either the Saturation pot is too small or the rate the SCAS tries to help you? or compensate is too high, also why does it lead your inputs.

Push your stick right/left and see the green plus leads you to your stops - this is why you sometimes go upside down when trying to side slip or even turn

Controls indicator says a lot, many dont fly with it on, i find it impossible not to know where my axis are.

Watch the rudder go left right like a banshee never catching up and always saying "hey i want to be over here, not where you want it" - very hard not to be in a crab for the whole flight.

Slip gauge and FPM dont seem to indicate correctly.

The smallest movement of the collective has you going up/down, left or right, while the scas tries to control it, it is so so sensitive.

Im likely wrong but the SCAS is either supposed to compensate/stabilize and/or dampen your crazy inputs - it is not supposed to say "Sorry buddy im going this way"

Likely the manual or someone important that knows will need to give an explanation of what the SCAS does for us at some point, and what it doesnt do for us.

Speculation will continue.....

its EA and i am not a SME - just an observer assuming thats not what it is supposed to do.. be gentle.

Edited April 17, 2023 by GremlinIV

[admiki]

1 hour ago, GremlinIV said:

Took watching this to realise what you were doing, with replays and patches etc - then in the last bit the lights came on - yah thats not good...

Regardless of what they have or havent done - i am not convinced it is better or worse than before...

The SCAS pot seems limited and it seems all the axis add to the same pot - so if your in ALT hold flying along nice but close to saturation on the pedals any input from any axis will likely over-saturate and your altitude will start to oscillate, this will affect those close to saturation pedals and into a bank you go, followed by roll and pitch, followed by interaction with the ground in an unpleasant manner. Or at best some unprofessional looking flight.... - coming to a high hover from this flight also gets some odd yaws and oscillations of flight.

Seems either the Saturation pot is too small or the rate the SCAS tries to help you? or compensate is too high, also why does it lead your inputs.

Push your stick right/left and see the green plus leads you to your stops - this is why you sometimes go upside down when trying to side slip or even turn

Controls indicator says a lot, many dont fly with it on, i find it impossible not to know where my axis are.

Watch the rudder go left right like a banshee never catching up and always saying "hey i want to be over here, not where you want it" - very hard not to be in a crab for the whole flight.

Slip gauge and FPM dont seem to indicate correctly.

The smallest movement of the collective has you going up/down, left or right, while the scas tries to control it, it is so so sensitive.

Im likely wrong but the SCAS is either supposed to compensate/stabilize and/or dampen your crazy inputs - it is not supposed to say "Sorry buddy im going this way"

Likely the manual or someone important that knows will need to give an explanation of what the SCAS does for us at some point, and what it doesnt do for us.

Speculation will continue.....

its EA and i am not a SME - just an observer assuming thats not what it is supposed to do.. be gentle.

 

I can't recall if you answered on Raptor's question of using force trim, so I'll ask again: do you use force trim and how?

[deloy]

My personal observations after patch:

1. We can see what heading hold is doing using new controls indication , this shows implementation of some real world yaw channel behaviour, although fine tuning in yaw channel needed . You can clearly see when you apply pedals , when the heading hold is engaged or disengaged, by some fancy curve setting I managed to improve response for my setup . Still not perfect though 

2. Strange zombie collective channel behaviour is finally gone !

3. Most of us having issues with help being unstable is probably due to SAS response , which is reduced in my opinion , don’t know why as they said they didn’t change that. Through my numerous tests I am pretty certain something is affecting SAS response , which is causing PIOs, this should not happen in my opinion.

4. Controller settings somehow changes how the helo responds, I changed to instant trim and removed curves , reducing saturation. Made a certain difference .

5. As before , force from behaviour is still far from perfect 

 

 

[GremlinIV]

15 hours ago, admiki said:

I can't recall if you answered on Raptor's question of using force trim, so I'll ask again: do you use force trim and how?

OK so i see how this is relevant now, i thought it was just a survey, not an, if you do that you have to use that or it wont act like that to do that, question.

So i come from the Huey, with a Warthog Hotas, i push the stick then bump the trim (up) and relax my stick, i never took a liking to holding trim for those small movements to set a hover or a heading etc.

I have the Special tab set to Central trim position for both cyclic and rudder (stops the doubling of input before getting back to centre), so once my trim is set, my physical controls then sit centred and relaxed.

I use this to set into a hover from the ground or from flight, and to get myself into level forward flight (speed set, Alt set, direction set), any changes from here are purely on the stick for say some active combat style stuff and i dont reset the trim at any point during this phase, except maybe to tidy up if speed, alt, direction changes are required, then as i return to normal level flight or hover or landing etc i will bump trim as required.

I can see if im holding trim (up) the green plus stays with the stick when i move it, my understanding was holding trim (up) was to de-saturate SCAS, so is this where I am going wrong?

I had my trim (down) Btn set to "reset trim" until recently, but maybe trim (Down) does something else in the future, trim (left,right) are set to the hold modes as per.

Summary:  I move my stick/pedal and press trim(up), then centre my stick/pedals, is this bad/wrong?

Just read Raptor Question again and not sure i answered it,

I would likely drop any hold mode i was in to change speed Alt heading etc re-trim using the methods above as required then re-select holds.

The reason for this mainly, is how much the helo becomes wobbly and unstable with big pedal inputs to rotate in a hover.

Reading above curves may be a feature so my curves are currently 16 for x/y and rudder, collect is linear 0.

 

Ahh maybe this still dont answer it,.....

Edited April 18, 2023 by GremlinIV

[JIGGAwest]

I know, work in progress.... And I appreciate the module. It's my favorite in all of DCS. I'm very thankful. 

I'm just going to leave simple feedback at this point.

There seems to be some major issues with roll sensitivity. Especially when high wind present. Also, with no wind...  I've at least a few times gone into an uncontrolled roll to the right when traveling lower than 90 knots. I was in aerodynamic trim, and this was much like the high speed rollover in the Hind early on. This was with wind present with the direction coming from roughly 5 o'clock at about 11-14 knots.

Additional issues with roll I've encounters are flying at speed 60-80 knots, making a left roll input followed by aft stick to maintain a tight turn. Then adding hard right rudder to swing the tail around. The aircraft basically cartwheels over to the right.

I've also had George as the pilot go into VRS from a stable hover with high wind present. Moving from a stable hover and increasing altitude.  Luckily I was able to switch seats quick and recover.

I hope these flight dynamics issues are addressed in the upcoming major flight model changes. Because, currently it's such a chore to fly the Apache.  It's just way to twitchy in the elements to be enjoyable. 

 

[GrEaSeLiTeNiN]

8 hours ago, JIGGAwest said:

I've also had George as the pilot go into VRS from a stable hover with high wind present. Moving from a stable hover and increasing altitude.  Luckily I was able to switch seats quick and recover.

Yeah, George as pilot goes into VRS quite easily. When that happens, I don't switch seats though but quickly take back control of the stick (press C) and fly out of the downdraft. Then return control to pilot George when stable (C again and AI interface).  

[Semaphore]

Its awfully quiet in here from an ED perspective and I would have thought there would have been some comments especially as the flight cxharacteristics of the Apache have changed dramatically since the last OB update.  Personally, I wish for a realistic flight model but not at the expense of playability.  Fortunately I have a good set up with regards controls but even still, the Apache is becoming extremely difficult to handle and I suspect others with less fancy/expensive controls are going to be disadvantaged considerably.

 

[Miro]

41 minutes ago, Semaphore said:

Its awfully quiet in here from an ED perspective and I would have thought there would have been some comments especially as the flight cxharacteristics of the Apache have changed dramatically since the last OB update.  Personally, I wish for a realistic flight model but not at the expense of playability.  Fortunately I have a good set up with regards controls but even still, the Apache is becoming extremely difficult to handle and I suspect others with less fancy/expensive controls are going to be disadvantaged considerably.

 

I fly on Ravcore Javelin, with twisted rudder, and i think flying Apache is extremely easy when You fly couple of hours, maybye even too easy comparable to real bird. I just think that in DCS after 200-300 hours of flight you start to get to perfection, and in real life it's probably not so much. You also say: "I wish for a realistic flight model but not at the expense of playability." Maybe game mode will work? Sim should have as close as possible to the real flight model.

Edited April 19, 2023 by Miro

[HC_Official]

hmmmm, after last patch she is a lot more of a handful to control

[Toge]

They have already stated facts about the topic, and as we're discussing the flight model which hasn't changed, I believe we're all just wrong and imagining things.

[admiki]

9 minutes ago, Toge said:

They have already stated facts about the topic, and as we're discussing the flight model which hasn't changed, I believe we're all just wrong and imagining things.

No, ED said they haven't changed it. Considering how much mess DCS code is, that does not mean flight model has not changed.

[MIghtymoo]

18 hours ago, JIGGAwest said:

I know, work in progress.... And I appreciate the module. It's my favorite in all of DCS. I'm very thankful. 

I'm just going to leave simple feedback at this point.

There seems to be some major issues with roll sensitivity. Especially when high wind present. Also, with no wind...  I've at least a few times gone into an uncontrolled roll to the right when traveling lower than 90 knots. I was in aerodynamic trim, and this was much like the high speed rollover in the Hind early on. This was with wind present with the direction coming from roughly 5 o'clock at about 11-14 knots.

Additional issues with roll I've encounters are flying at speed 60-80 knots, making a left roll input followed by aft stick to maintain a tight turn. Then adding hard right rudder to swing the tail around. The aircraft basically cartwheels over to the right.

I've also had George as the pilot go into VRS from a stable hover with high wind present. Moving from a stable hover and increasing altitude.  Luckily I was able to switch seats quick and recover.

I hope these flight dynamics issues are addressed in the upcoming major flight model changes. Because, currently it's such a chore to fly the Apache.  It's just way to twitchy in the elements to be enjoyable. 

 

I totally agree to above. I love flying helos, and have worked hard to like the Apache, but I do not feel "connected", as I do with the other helos like Huey or Hind.

I also have a Virpil CM3 stick and VKB rudder with very smooth/light movement. I can not believe how difficult it must be to handle for a person with less precise HW or less experience flying helis.

In no way can the real bird be as sensitive on the roll axis. 

Also the crazy right roll/cartwheel that comes sometimes, can not be how the real thing behaves. 

[BIGNEWY]

1 hour ago, Semaphore said:

Its awfully quiet in here from an ED perspective and I would have thought there would have been some comments especially as the flight cxharacteristics of the Apache have changed dramatically since the last OB update.  Personally, I wish for a realistic flight model but not at the expense of playability.  Fortunately I have a good set up with regards controls but even still, the Apache is becoming extremely difficult to handle and I suspect others with less fancy/expensive controls are going to be disadvantaged considerably.

 

Please read the previous posts by ED members in this thread. 

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

There have been no changes to the flight model in this patch, we can keep repeating that fact, but that is all we can do for now. Changes and tweaks are still to come in future patches and when they do happen they will be in the change log. 

Please everyone keep it constructive, we do appreciate the feedback. 

thank you

 

 

[Raptor9]

In addition to what BigNewy said, the flight model and SCAS behavior is not finished.

Just because we have commented on what has or has not changed in a given patch does not mean that we are saying the flight model is 100% realistic or complete.

[Semaphore]

On 3/22/2023 at 1:07 AM, Raptor9 said:

No changes have been made to the AH-64D flight model.

I cant see how thats true... the flight characteristics have dramatically changed since the last OB update and not for the better.

Id suggest trying to fly it yourself as now on take off she is exceptionally sensitive to rolling on her side where as before she would lift smoothly and hold herself quite stable, a;lso the collective is much more sensitive.  Life has simply become more challenging if piloting the rear seat only wiuthout a human CP/G.

Considering I’m not the only one suggesting changes to the Flight Model, surely it’s worth investigating by ED.. a side by side comparison which i believe may surprise you.

Edited April 19, 2023 by Semaphore

[Floyd1212]

26 minutes ago, Semaphore said:

Rubbish…. The flight characteristics have dramatically changed since the last OB update and not for the better.

I think calling the changes since the last OB patch "dramatic" is being a bit over-dramatic.

Go watch the video I posted further up on this page.  Toward the end I replay a track recorded in the previous OB version, and in the current OB version the helo lifts up and starts to drift back and to the left.  It doesn't suddenly roll over on to its side.  It would appear you don't need as much left and aft stick when you pick up in the latest build.  This is also confirmed when I pick up for the first time after patching and she wants to slip left because I was giving it the same left stick I was used to.

The changes in the behavior of the aircraft are subtle, but they are there.  It might not have been a change to the " core flight model" as ED discussed on page 3 of this thread, but to say the changes make it impossible to fly now (as others have implied) is a bit much.

Post a track of what you are experiencing and let the community try to help figure out what's going on.

[Semaphore]

2 minutes ago, Floyd1212 said:

I think calling the changes since the last OB patch "dramatic" is being a bit over-dramatic.

Go watch the video I posted further up on this page.  Toward the end I replay a track recorded in the previous OB version, and in the current OB version the helo lifts up and starts to drift back and to the left.  It doesn't suddenly roll over on to its side.  It would appear you don't need as much left and aft stick when you pick up in the latest build.  This is also confirmed when I pick up for the first time after patching and she wants to slip left because I was giving it the same left stick I was used to.

The changes in the behavior of the aircraft are subtle, but they are there.  It might not have been a change to the " core flight model" as ED discussed on page 3 of this thread, but to say the changes make it impossible to fly now (as others have implied) is a bit much.

Post a track of what you are experiencing and let the community try to help figure out what's going on.

I hear what you are saying but to quote your own words 'It would appear you don't need as much left and aft stick when you pick up in the latest build' which therefore suggests the flight model has been changed in the latest patch which is contrary to what ED are saying in that no changes have been made!

[Sandman1330]

Yeah something serious has changed. The roll axis seems extremely sensitive now, and the uncommanded rolls are back. Call it FM, SCAS, whatever - something changed for the worse.

I've never flown a helicopter that was prone to snap rolling itself inverted without some serious attempts to mishandle it....

I kind of wonder if it's related to the ball. I think it's already been documented in a bug report, but the ball behaviour is incorrect in the IHADSS - if you bank, the ball follows the bank. It shouldn't, if it's a coordinated turn it should stay centered. Now, without the seat of the pants feel to ensure you aren't in uncoordinated flight, and without a working ball indicator, it's possible during maneuvering to fly extremely uncoordinated. Is this possibly causing some of the weird behaviour?

Edited April 22, 2023 by Sandman1330

[Sandman1330]

I did some quick testing, and found something interesting.

I set the apache up at about 85% torque and 100kts. This resulted in a slight climb, but I wanted to ensure airspeed and torque remain constant in the turn so as not to change coordinated flight parameters. With the ball centered, I then started a turn as tight as I could without losing airspeed or having to increase torque. So, with the collective and pedals frozen, I turned the aircraft and maintained (within 5kts / 5%) my parameters.

In both turns, the ball immediately falls to the inside of the turn, as if it's following gravity, not the G loading of the aircraft as it should. This is where it got interesting:

In a left turn, the SCAS yaw channel slowly motored over to re-center the ball in the turn. On roll-out, the ball deflected heavily to the right, until the SCAS motored back to my trimmed center, where the ball re-centered. So in a left turn, it seems the SCAS wants to correct for the incorrect ball behaviour, resulting in a significantly uncoordinated turn.

In a right turn, none of that behaviour was exhibited - the SCAS stayed centered in the trimmed position, and on roll out the ball centered again on it's own.

So in addition to the ball behaviour, there seems to be some inconsistency in how the yaw channel deals with it.

Add to this, if I try and center the ball myself in the turn (as a good helicopter pilot should always do), I'm actually putting the aircraft in a significantly uncoordinated situation. I wonder if this uncoordinated flight is causing some of the wonkyness / uncommanded roll that we are seeing...

Here's a track file of my testing:

 

 

apache ball.trk