Force Trim

[Japo32]

Page 250 of the manual. Someone did this? Makes any difference? A friend told me that the aircraft is much easier to fly. I didn't notice much difference, but because now I manage it very smoothly already:

https://gyazo.com/f62c63f4ba7486b54c88b71c84642a59

[scoobie]

I'm only following ideas from other folks in this thread. This is how "Special" tab under Options could look like. I ticked some options and left other unticked just an example.

You can get "instant trim", "timed release trim" (adjustable), "center position trim" AND you can have new "non-locking center position trim". Robert is your mother's brother.

OPTIONS->SPECIAL:

[v] Cyclic Trim

                [v] Release axis when it gets centered

                [v] Release both axes after 0 ------o--- 1 seconds

[ ] Anti-torque Pedals Trim

                [ ] Release axis when it gets centered

                [v] Release axis after 0 ---o------ 1 seconds

 

LEGEND:

[ ] - unticked check box

[v] - ticked check box

------o--- - a slider with "o" indicating position

Options for pedals are greyed out (disabled, currently non-clickable), because the "main" trim option says we don't want trim at all.

If all check boxes for a particular trim (cyclic or pedals) are ticked, it means "whichever condition is met first" (logic "or").

ED have code for both options already, it's just the time delay is now hard-coded, and both options are currently "either-or" (mutually exclusive, selected with the drop-down list).

Edited March 25, 2022 by scoobie

[Lurker]

10 hours ago, agamemnon_b5 said:

That's not the same as holding down the trim button for every movement.  I'm more or less contesting that holding the trim button is the "proper" way to do things

 

I never said that you need to hold the trim button for every movement. Just that when you do trim, that you should use proper technique so as not to get into trouble. I guess I'm spoiled by my FFB stick, where it's just natural to hold down the trim button (in every chopper) so that the FFB motors "release" the stick. 

Edited March 25, 2022 by Lurker

[Hiob]

6 minutes ago, Lurker said:

I never said that you need to hold the trim button for every movement. Just that when you do trim, that you should use proper technique so as not to get into trouble. I guess I'm spoiled by my FFB stick, where it's just natural to hold down the trim button (in every chopper) so that the FFB motors "release" the stick. 

 

Yes, in the real aircraft and with a FFB-stick (witch is the closest you can get in regards to input devices, no question) it is without a doubt best practice to press-hold-trim-release, but with any other device - spring-centered joysticks in particular - it simply doesn't matter at all, if you do that or just press and release in your desired position. Why? Because, the force gradient, that is relieved in the real aircraft and the FFB when you press trim, never goes away with a spring centered device anyway.

Forgive me for saying that, but with a FFB-Joystick you are the exception, not the norm, and you are confusing people unnecessarily. I would really beg you to actually test things out, before claiming things with such pressure.

[Lurker]

10 hours ago, agamemnon_b5 said:

Casmo just released a video about the trimmer.  Same thing; he does not hold down the trim button.  He makes adjustments then hits trim.

Casmo seems to be fighting the trimmer mode, it appears that he has selected FFB mode in the special options despite not having FFB controls. I know he is an SME but what he is demonstrating is his technique for flying the DCS Apache, it's what he is comfortable with. I might be wrong about this but I don't think that's how he would be flying a real Apache. 

[Vladinsky]

19 minutes ago, Lurker said:

Casmo seems to be fighting the trimmer mode, it appears that he has selected FFB mode in the special options despite not having FFB controls. I know he is an SME but what he is demonstrating is his technique for flying the DCS Apache, it's what he is comfortable with. I might be wrong about this but I don't think that's how he would be flying a real Apache. 

While instant trim is listed as FFB Friendly, it is functionally the same as Default trim in the Mi-8, UH-1H, Ka-50 and Mi-24. ED changing the name of it seems to have caused a great deal of the confusion.

[scoobie]

2 hours ago, Vladinsky said:

ED changing the name of it seems to have caused a great deal of the confusion.

No. It's not only that.
1. In Huey there's a significant delay in "Default". Nearly one second of delay. So don't say "Default" is the same everywhere.
2. In the Hip, the delay in "Default" was decreased to very small (now it's also referred to as "instant trim", "FFB friendly" etc.), because she's sluggish enough (intertia + perhaps quite "agressive" SAS), so that it doesn't hurt. I, myself, didn't notice there was a change from Huey to Hip, I can fly both OK.
3. In more agile (than Hip) helos such as Apache/Hind the very small delay became annoying when you want to introduce larger trim setting in a single "step", e.g. when picking up, crossing through ETL etc.
4. For this reason some people switched to "Centering Position" trim, which doesn't have this drawback, but in turn this one can make you crash.
So it's not only about the new names of the options.

2 hours ago, Lurker said:

Casmo seems to be fighting the trimmer mode

Yep. SME himself is struggling. Symptomatic, isn't it?

 

Edited March 25, 2022 by scoobie

[Raptor9]

I think most of the confusion is from people unfamiliar with how DCS simulates force trim in helos. People either making their first entry into DCS helos with the Apache, or people coming into DCS that are brand new altogether.

[Vladinsky]

12 minutes ago, scoobie said:

No. It's not only that.
1. In Huey there's a significant delay in "Default". Nearly one second of delay. So don't say "Default" is the same everywhere.
2. In the Hip, the delay in "Default" was decreased to very small (now it's also referred to as "instant trim", "FFB friendly" etc.), because she's sluggish enough (intertia + perhaps quite "agressive" SAS), so that it doesn't hurt. I, myself, didn't notice there was a change from Huey to Hip, I can fly both OK.
3. In more agile helos such as Apache/Hind the very small delay became annoying when you want to introduce larger trim setting in a single "step", e.g. when picking up, crossing through ETL etc.
4. For this reason some people switched to "Centering Position" trim, which doesn't have this drawback, but in turn this one can make you crash.
So it's not only about the new names of the options.

You don't seem to be disputing anything I've actually claimed. I agree with all of your points.

 

24 minutes ago, Raptor9 said:

I think most of the confusion is from people unfamiliar with how DCS simulates force trim in helos. People either making their first entry into DCS helos with the Apache, or people coming into DCS that are brand new altogether.

It does appear that way, it's exciting to see DCS helicopters get the attention they deserve.

 

[scoobie]

1 hour ago, Vladinsky said:

You don't seem to be disputing anything I've actually claimed.

I'm sorry! I'm too fast answering, too slow reading

[shrimpy_dikdik]

2 hours ago, Raptor9 said:

I think most of the confusion is from people unfamiliar with how DCS simulates force trim in helos. People either making their first entry into DCS helos with the Apache, or people coming into DCS that are brand new altogether.

Actually I've seen many posters here complaining or struggling with the Apache trim who are very keen to state they have many years experience with other DCS helicopters. I have about 25 minutes experience in the Hind and have taken to the Apache trim like a duck to water. Maybe those of us with no experience and maybe more importantly no expectations are actually finding it easier. 

Edited March 25, 2022 by shrimpy_dikdik

[Raptor9]

6 minutes ago, shrimpy_dikdik said:

Maybe those of us with no experience and maybe more importantly no expectations are actually finding it easier. 

Perhaps.

[Ben Sones]

 

18 hours ago, Raptor9 said:

There are white arrows at the base of each cyclic that show this, albeit one is still missing.

 

The problem with this is that nobody is going to be looking down at their lap while trying to transition and trim a helicopter. The control map is probably a better reference for how the cyclic is trimmed, for the time being. 

 

17 hours ago, Lurker said:

Redkite's video is just adding more confusion in to the mix. Not once did he demonstrate the proper technique to fly the Apache, which is HOLD the trim button, then move your flight controls, then RELEASE Trim. This is regardless of whether you have a 50$ grandma's joystick, or 2000$ worth of flight equipment stripped straight out of a real Apache. 

If you are moving your flight controls and then pressing and releasing trim, you will get into trouble for all the reasons that Redkite demonstrated in the video above. 

 

 

I'm not entirely sure what you mean. Because of the way in which DCS models the trim, moving the stick to a new position and tapping the force trim button has exactly the same effect as holding in the force trim button and dragging the trim point to the same location. The controls do not recenter until you "drop" the trim point, so while you can see it being dragged around in the control map, this has no effect whatsoever on your control inputs. The trim remains centered at that last position it was at until you let go of the button. 

In the real helicopter, the reason to hold in the button is that it releases the magnetic brake, so as long as you hold the button, the controls move freely and have no centering action. There is no way to simulate that on a standard flight stick or rudder pedals in DCS, though, as they have a physical, fixed center. So, in DCS, holding in the button does nothing, in-game. 

 

[Raptor9]

3 minutes ago, Ben Sones said:

The problem with this is that nobody is going to be looking down at their lap while trying to transition and trim a helicopter.

I wasn't implying they would or should, I was responding to the post directly above mine when someone mentioned he was surprised there was no real-life visual markings to indicate control position.

[Fromthedeep]

22 minutes ago, Ben Sones said:

Because of the way in which DCS models the trim, moving the stick to a new position and tapping the force trim button has exactly the same effect as holding in the force trim button and dragging the trim point to the same location. The controls do not recenter until you "drop" the trim point, so while you can see it being dragged around in the control map, this has no effect whatsoever on your control inputs

This is actually a great topic for SMEs to address. In the Ka-50, moving the stick and then pressing the trimmer will cause you to have issues because of the autopilot channels and you can only avoid that if you either hold trim and move the stick and then release or use FD mode. Otherwise, the AP will fight you at the newly trimmed position. Is the trim in the real Apache (the SCAS and FM of the in game one is still WIP, so let's have a baseline understanding of how it should work once complete) work like that, or does it make any difference? Assuming that your attitude and/or altitude hold modes are not engaged.

Edited March 25, 2022 by Fromthedeep

[Lurker]

7 minutes ago, Ben Sones said:

I'm not entirely sure what you mean. Because of the way in which DCS models the trim, moving the stick to a new position and tapping the force trim button has exactly the same effect as holding in the force trim button and dragging the trim point to the same location. The controls do not recenter until you "drop" the trim point, so while you can see it being dragged around in the control map, this has no effect whatsoever on your control inputs. The trim remains centered at that last position it was at until you let go of the button. 

In the real helicopter, the reason to hold in the button is that it releases the magnetic brake, so as long as you hold the button, the controls move freely and have no centering action. There is no way to simulate that on a standard flight stick or rudder pedals in DCS, though, as they have a physical, fixed center. So, in DCS, holding in the button does nothing, in-game. 

 

Wouldn't moving your stick and hitting press and release mess with the Apache SAS systems though? AFAIK (please correct me if im wrong) the SAS systems stabilize and try to hold your current trim either until their control authority is exceeded (10% if I remember correctly) or the trim button is pressed. So pressing the trim button down, disengages the SAS and then once you reach your desired new trim conditions releasing it engages the SAS again. Seems like while it wouldn't make any difference from a control input option, it should make a little bit of difference because of the SAS systems in the Apache. 

[MAXsenna]

27 minutes ago, shrimpy_dikdik said:

Actually I've seen many posters here complaining or struggling with the Apache trim who are very keen to state they have many years experience with other DCS helicopters. I have about 25 minutes experience in the Hind and have taken to the Apache trim like a duck to water. Maybe those of us with no experience and maybe more importantly no expectations are actually finding it easier. 

 

I think you might be correct, and it's my personal sentiment for myself. 

I have currently 200 plus hours in my log book for  other helicopters (which must be very wrong ), and a struggle a little with the Apache, even with FFB and non centring pedals. But I'm getting there it's just different. For me it's like going from non-FFB to FFB in the Gazelle. (Just couldn't do it, so I'm sitting that one out until new FM). 

So for me it's just a matter of practice, and getting different perception and muscle memory, as I find the Hind the Hip very easy with FFB. 

Cheers! 

[Raptor9]

On 3/25/2022 at 8:06 AM, Fromthedeep said:

 Is the trim in the real Apache (the SCAS and FM of the in game one is still WIP, so let's have a baseline understanding of how it should work once complete) work like that, or does it make any difference? Assuming that your attitude and/or altitude hold modes are not engaged.

On 3/25/2022 at 8:09 AM, Lurker said:

Wouldn't moving your stick and hitting press and release mess with the Apache SAS systems though? AFAIK (please correct me if im wrong) the SAS systems stabilize and try to hold your current trim either until their control authority is exceeded (10% if I remember correctly) or the trim button is pressed. So pressing the trim button down, disengages the SAS and then once you reach your desired new trim conditions releasing it engages the SAS again. Seems like while it wouldn't make any difference from a control input option, it should make a little bit of difference because of the SAS systems in the Apache. 

With ATT hold off, when you press the force trim button on the Apache, it shouldn't turn off the SAS servos (which it appears to do currently), it just removes the force gradient from the mag brakes allowing you to set the force trim at a new position. When below 40 knots, when Heading hold is active, it also suspends the Heading hold while force trim is pressed.

The SAS logic doesn't try to hold the current trim, the mag brakes on the cyclic/pedals are what holds the trim. The SAS logic provides rate damping to increase overall stability.

The ATT modes on the other hand, do try to hold specific values when enabled.  However, they will not fight you like the Ka-50's will.  They have breakout values that recognize deliberate control inputs by the pilot and when to intuitively let the pilot maneuver the helicopter, and then will re-engage when certain criteria are met. Just like with the Heading hold, when the force trim is pressed, the current ATT mode is suspended until the force trim release is no longer pressed, after which it will pick up the new values. The ATT hold should not simply disengage when the controls are moved, but again, WIP.

When the SCAS system of the AH-64D is more fleshed out, I'm sure they will update the manual to reflect it.

In the real aircraft, and with other helicopters, you may encounter something called "force trim overshoot". When you fight the force gradient of the mag brake to such an extreme position from the trimmed position, and then press the force trim release, all the force gradient you are applying pressure against goes away all at once, and it can result in the pilot inadvertently pushing the controls much further than they intend, causing an aggressive input.  Because of this, during aggressive maneuvers (such as evasive maneuvers) it is taught that you either hold down the force trim throughout the entirety of the maneuver, or you do not interrupt the force trim throughout the entirety of the maneuver. This is intended to avoid the possibility of an inadvertent, aggressive input into the flight controls due to force trim overshoot during rapid maneuvers that may cause a departure from the pilot's intended maneuver or even aircraft damage.

In real-life, some pilots hold down the force trim until they finish moving the controls, others bump it as they are moving it or after they move it, but only during relatively small adjustments; most hold down the force trim during the entire control movement when making large control inputs. Having said all that, due to the method by which DCS simulates force trim, and the nature of having physical controls and virtual controls, these principles and techniques don't always directly correlate between real life and DCS.  So it still comes down to what technique works for you, based on your own preference and specific physical gaming hardware you use.

[Ben Sones]

27 minutes ago, Lurker said:

Wouldn't moving your stick and hitting press and release mess with the Apache SAS systems though? AFAIK (please correct me if im wrong) the SAS systems stabilize and try to hold your current trim either until their control authority is exceeded (10% if I remember correctly) or the trim button is pressed. So pressing the trim button down, disengages the SAS and then once you reach your desired new trim conditions releasing it engages the SAS again. Seems like while it wouldn't make any difference from a control input option, it should make a little bit of difference because of the SAS systems in the Apache. 

The SCAS provides very minimal dampening that helps with stability if you take your hand off the cyclic, but which is pretty much immediately overcome when you make any control input. If it didn't, then you'd need to hold down the force trim button just to make regular control inputs, which defeats the purpose of even having it. You can test it for yourself, though--try retrimming with the press and hold method, and then try again via moving the cyclic and then tapping the button. Both methods have exactly the same effect, in game. 

[agamemnon_b5]

10 hours ago, Japo32 said:

Page 250 of the manual. Someone did this? Makes any difference? A friend told me that the aircraft is much easier to fly. I didn't notice much difference, but because now I manage it very smoothly already:

https://gyazo.com/f62c63f4ba7486b54c88b71c84642a59

The way it's working now, since you have to pretty much be in trim to begin with, it's not even a heading hold and more of a glorified trim hold.  Probably will be fleshed out more in future updates.

[Fromthedeep]

35 minutes ago, Raptor9 said:

With ATT hold off, when you press the force trim button on the Apache (...)

Thank you, great answer and it really illustrates the point you often bring up; the SCAS of the Apache sounds to be very intutive to use to the pilot even though it has lots of conditional logic and complex submodes behind them. 

[Raptor9]

5 minutes ago, Fromthedeep said:

Thank you, great answer and it really illustrates the point you often bring up; the SCAS of the Apache sounds to be very intutive to use to the pilot even though it has lots of conditional logic and complex submodes behind them. 

The only time I've ever "fought" the hold modes is when trying to hold a slight bank in a wide orbit. When the Attitude hold is on and you are within 3 degrees of roll, it will auto-level the aircraft. So if you are trying to hold a slight bank, it can sometimes think you are trying to level the aircraft and do it for you.

[elchacal]

On 3/19/2022 at 4:30 AM, HelipilotEGLW said:

Hi,

it might better just to have a trim reset to centre command. I know its not realistic; but most of us are using spring loaded joysticks, i think it would help. 

I agree!

[dburne]

Well I have settled for center spring trim for my cyclic, and for no centering trim for my Crosswind Pedals with Damper mod. I just removed the spring on the pedals and adjusted the damper to my liking. Finally today made some nice landings from a hover along with take offs into a hover.

It does present a little bit of a challenge for me in that as I got older I developed neuropathy in my lower legs and especially my feet. They feel pretty numb so that gives me a challenge, but would do so no matter the trim method I used really. I think I will be sticking to what I have now. Had to re-train my brain for when I press force trim button and return cyclic to center I do not return my rudder pedals to center. Getting better at that now though.

[Dlam1995]

So I'm probably going to add a bit to this that might already have been covered, but has anyone noticed a very weird tendency for the Apache to just want to bank left no matter what?