About the TRIM (from devs)

[Ramsay]

Can't be since their SME, RL Gazelle pilot said that its close enough to the real thing.

With SAS enabled, the SA 341 Gazelle has attitude/heading stability, I expect the SA 342M is similar.

On the cyclic there are 2 buttons for the SAS; with one pressed you set the course you want to fly. When you release this button, it keeps this attitude and heading. The other button is to switch SAS off. With SAS engaged you can completely release all controls for at least 3 minutes (according to the POH). Very handy when you need to grab your maps or to take a breath :-)

Source: SA 341 pilot post

 

perhaps the SAS is masking the magnetic brake/trim attitude hold behaviour?

 

With SAS disabled, I would have expected the Gazelle to

 

• 
  
• behave like a 'twitchy/sensitive' Huey with the SAS servo actuators disabled and the cyclic using a 'pure' mechanical control linkage.
  
• the magnetic brake/trim to hold/adjust the position of the cyclic, not the Gazelle's attitude.
  

With SAS off, it also flys great but it is more stable with SAS switched ON.

Edit: The magnetic brake release also connects to the SAS pitch and roll computers and, with SAS enabled, attitude/heading hold is probably modelled correctly.

 

Still waiting on 1.5.4 to come to steam, to test the new changes but have faith you guys (Polychop) will continue iterate the FM and SM using RL pilot feedback to make the SA 342M module as realist as possible.

Edited July 4, 2016 by Ramsay

[Zee Pet]

So is what they're planning true to the real helicopter, or are they just doing their own thing?

[Ramsay]

So is what they're planning true to the real helicopter, or are they just doing their own thing?

I believe Polychop will be true to the real helicopter, the quality of the cockpit and systems modelling speak for themselves and there'd be little point in taking time out visiting AB's for pilot feedback or dedicating months/years of their free time to make the module just to "do their own thing" (no one gets rich making flight sims).

 

We make the effort to work with real pilots exclusively, cause this is the best source you can get next to flight manual or any data from the manufacturers or even NASA.

I can only state that we make our homework always and try to solve the issues that are identified as such.

Some stuff might not be an issue but pilot error. Happened to me also, as we are all just humans.

Pat01's description

Hi Gents

The "normal" way to use the magnetic brake is :

1- manoeuver your helicopter to the wanted attitude

2- press and release the magnetic brake button (same as T key, no hold needed)

that's all

The helicopter should try to maintain the trimmed attitude.

matches SAS flight control described by the SA341 owner.

 

On the cyclic there are 2 buttons for the SAS; with one pressed you set the course you want to fly. When you release this button, it keeps this attitude and heading.

I think what confuses matters is that TRIM and SAS (Attitude and Heading) are set in the same action (button) and with SAS enabled the Gazelle *may* need to be flown like the ka-50 autopilot

 

 

This of course gets me wondering about SAS and yaw and why yaw/rudder input is needed entering a hover check if the SAS can maintain heading - at which point, I have to trust Polychop's team or find a real Gazelle pilot to ask how all this stuff works.

[KoN]

I think we all need a video on the latest setup for auto hover , in 1.5.4 and 1.5.3 stable .

Also is this all working in Multiplayer as i find in single player i have little difficulty in hover engage 1.5.4 beta , but online i yet to do it with out crashing spinning into the ground .

[heloguy]

Hi Gents

The "normal" way to use the magnetic brake is :

1- manoeuver your helicopter to the wanted attitude

2- press and release the magnetic brake button (same as T key, no hold needed)

that's all

The helicopetr should try to maintain the trimmed attitude.

 

Not sure what the definition of normal is, but as a helo pilot IRL, this is not how I fly. In any of the helicopters I have flown, if you do this, when you press the trim release(magnetic brake in some helicopters), all of that pressure you are holding against the force gradient will cause you to slightly push through whichever direction you are pushing. If you do a quick push, then release, you will likely reset the trim a couple degrees further than you meant to.

 

The current implementation for ffb in the Huey, Blackshark, and Mi-8 are spot on compared to other helicopters I have flown, keeping in mind I have never flown any of the helicopters in DCS for real.

 

The fact is, if you aren't using a ffb stick, you have to suspend some reality, and have a good grasp on how it works to be able to fly effectively. I have had some of my friends who are pilots try flying DCS before I picked up a ffb joystick, and they all had problems with the trim setup. That being said, I think what previous modules have done is about the best they can do given current hardware.

 

Now, if this module would just have native ffb support, it would be on par with the other helos as far as controllability.

[Dunravin]

 

Anyway, if not, be advised that once the FFB support will be released, you will be able to use the standard Kamov-50 method.

 

From France with love ;)

 

Nicolas

 

Hello, I have a force feedback stick, can you confirm if the FFB support has been fixed? As of last night I still could not get a sensible FFB effect in this AC.

 

The 'standard Kamov-50 method' (for FFB?) you refer to I presume is the same as in the Huey where the pilot holds the trim button down while moving the cyclic, this removes all stick forces and allows for incredibly smooth control, when you release the trimmer button the stick is locked in place where you left it. Brilliant just what a pilot wants. For this to work correctly you need to apply 100% FFB in windows game controllers settings so this stick locks securely and you can hands off and it will hold a hover.

 

But... in the Gizelle, my stick is always 100% forces whether the button is pressed or not, a flick of the Mag switch to down does nothing.

 

So the result is that you have to apply much force to control attitude and subsequent presses of the trim button jerk the stick unpredictably resulting in crashing the heli. How are you supposed to fly with full FFB pressure acting on the stick all the time? Alternatively at very low FFB setting the stick is quite usable but then the Mag lock has no force available to lock!

 

The situation is retarded. Its a no win situation whatever you set things too.

 

So my question is what is the point of this trimmer? It does nothing comprehensible. There's no option to make it function like the Kamov and Huey. The other option is the fine trimmer which works exactly like heli trimmer in ArmA 3 - utter pants on its own but imagine very useful with a working FFB trimmer solution.

 

I notice there is now two FFB sliders in the special menu, after sliding these to both extremes and subsequent testing I could not discern what the intention was with these sliders. Are they in addition to the FFB tune options available in the Axis Binding options? What is their meaning, do we really need more options? Do they override the Axis Tune options or do we have to set both or what? They did not appear to have actual FFB effect but rather seemed to lag responses, most noticeable when rolling, pitch not as much.

 

All in all I cannot fathom the intention, and my concerns lead me to believe that Polychop does not have much of a clue what to do about it.

 

Is it too late to request a refund? Totally unsatisfied with this product. I can fly it without FFB enabled but even then there a flight model issues I feel should not be happening even in a super light agile heli. For instance in level flight a slight roll left will induce some lift perpendicular to the rotor plane when in actual fact all helicopters in a bank will tend to slip down in the plane of the rotor requiring a bit more collective to balance that out. This anti gravity anomaly seems to have been reduced since the last time I flew but its still noticeable.

 

Basically I have no faith in your product in its current iteration. I have no desire to fly it and am disappointed with the flight model.

[Hawkeye60]

All in all I cannot fathom the intention, and my concerns lead me to believe that Polychop does not have much of a clue what to do about it.

It is clearly stated before any purchases are made that this is a beta release.

 

BETA!

 

They are the first to implement multi crew (even though there are problems to work out)

 

Cutting edge stuff!

 

Stay on the edge and you will occasionally slip or fall off!

 

My mom always told me that patience was a virtue.

(Mom was always right!)

 

We need a lot of virtue around here!!!!!!:D

 

Thank you.

 

Safe landings

[xray20]

How does all of this relate to creating an accurate simulation of the controls? Is it necessary to have FFB to simulate the magnetic brake?

Does the magnetic brake hold the cyclic in position in RL?

I'm trying to scratch build accurate controls for this simulation. If I build some sort of magnetic lock on the roll and pitch axes (by solenoid?) will that give an accurate approximation to RL?

[TripRodriguez]

Not to complicate matters further, but I have questions also. Some of these are not specific to the Gazelle, but this is the helicopter I plan to be spending all my time in. There are plenty of (seemingly conflicting) posts in this thread about how these trims work in DCS, my questions are all relative to the REAL aircraft behavior.

 

1- Real Heli pilots: How much "centering" force does a helicopter have on the cyclic? Under what circumstances (if any) does it decrease or increase? How does oil damping of sim sticks factor into realistic feel? (would force feedback plus oil damping be ideal?)

 

2- Are the two trim functions in the DCS Gazelle manual (and respective buttons indicated on stick grip in the manual) true to the real aircraft?

 

3- I think I understand the way the Mag Brake function would work in the real helicopter ("centering" force moves to new location so you don't have to fight it). How does the trim actuator function work?

 

Thank you for your patience and efforts in answering our many questions!

 

Trip

[Ramsay]

my questions are all relative to the REAL aircraft behavior.

 

1- Real Heli pilots: How much "centering" force does a helicopter have on the cyclic? Under what circumstances (if any) does it decrease or increase? How does oil damping of sim sticks factor into realistic feel? (would force feedback plus oil damping be ideal?)

This Flight Test of the Aerospatiale SA-342 Helicopter, Aug 1975 gives control deflections but no stick forces.

2- Are the two trim functions in the DCS Gazelle manual (and respective buttons indicated on stick grip in the manual) true to the real aircraft?

AFAIK, yes.

 

3- I think I understand the way the Mag Brake function would work in the real helicopter ("centering" force moves to new location so you don't have to fight it). How does the trim actuator function work?

I haven't found good pictures for the Gazelle.

 

AFAIK there is a manual 'friction device' at the base of the stick for when the mag brake is disabled/off.

http://www.avialogs.com/en/aircraft/france/aerospatiale/as341gazelle/flight-manual-gazelle-sa-341g.html

 

The control linkage looks to have dampers and free sliding springs. The mag brake *may* lock the end of the spring/damper so it no longer slides, so giving a centring force for the cyclic. But I'm only guessing. On some systems the dampers and springs are separate.

 

SA 341G

 

AH-64 Magnetic Brake

 

 

 

IIRC a larger Aerospatiale helicopter with a trimmer hat controlled electric motors and linkage/cranks for fine trim adjustment near the base of it's cyclic but I didn't grab a picture/note the link.

Edited February 3, 2017 by Ramsay
Add picture

[TripRodriguez]

Thanks Ramsay, I've been reading continuously since posting those questions and have a much better understanding now of the trim functions, though your insight as to how these physically operate are the first I've seen.

 

(Note: The following is Real Life stuff!)

 

My understanding now is that "Mag Brake" moves the "spring center" to the current location of the stick so that you aren't fighting the stick to hold it in a position off center to maintain level flight etc..

 

My understanding is that the "Trim Actuator" function seems to work more or less like the trim functions I'm accustomed to from fixed wing aircraft, though whether or not using this would move the spring center of the physical stick in the real helicopter is still unknown to me.

 

I'm also not at all sure if the "spring" tension in a helicopter cyclic is purely artificially generated or if there is a natural pressure (like that in old fixed wing aircraft generated by air flowing over control surfaces) and the mag brake artificially overcomes that natural springiness.

 

Trip

[nomdeplume]

My understanding now is that "Mag Brake" moves the "spring center" to the current location of the stick so that you aren't fighting the stick to hold it in a position off center to maintain level flight etc..

Yes, but keep in mind the first post in this thread (for the DCS Gazelle module specifically): Your TRIM will keep the current angle of the Gazelle itself, not the cyclic one. So it is not acting quite like a normal magnetic brake trimmer would, and does in other DCS helicopters.

 

My understanding is that the "Trim Actuator" function seems to work more or less like the trim functions I'm accustomed to from fixed wing aircraft, though whether or not using this would move the spring center of the physical stick in the real helicopter is still unknown to me.

Well, I don't know either, but if it didn't move the centre position it would IMHO be extremely bizarre behaviour.

[TripRodriguez]

Yes, but keep in mind the first post in this thread (for the DCS Gazelle module specifically): Your TRIM will keep the current angle of the Gazelle itself, not the cyclic one. So it is not acting quite like a normal magnetic brake trimmer would, and does in other DCS helicopters.

 

 

As I stated in that post, I was only discussing the real helicopter behavior, not DCS. Sorry if I cause additional confusion in a thread that is already rife with it!

[Ramsay]

though whether or not using this ["Trim Actuator"] would move the spring center of the physical stick in the real helicopter is still unknown to me.

IIRC the Aerospatiale diagram with electric trim adjustment near the base of the cyclic looked to adjust the cyclic position as well as the control linkage as it was all connected but can't be 100% sure I'm correct.

 

Although the control linkage/cranks differed from the AH-64 and UH-1C diagrams, imagine if - as well as the 'mag brake' arm that rotates freely or locks, fixing the end of the centring spring. The arm/linkage had an electric motor to fine tune the position of the centring spring (Force Gradient).

Edited February 3, 2017 by Ramsay

[TripRodriguez]

IIRC the Aerospatiale diagram with electric trim adjustment near the base of the cyclic looked to adjust the cyclic position as well as the control linkage as it was all connected but can't be 100% sure I'm correct.

 

Although the control linkage/cranks differed from the AH-64 and UH-1C diagrams, imagine if - as well as the 'mag brake' arm that rotates freely or locks, fixing the end of the centring spring. The arm/linkage had an electric motor to fine tune the position of the centring spring (Force Gradient).

 

Ah this makes sense to me as well. Very good sir!