Problems with Trim and Spin

[doveman]

These are two separate problems.

 

1) If I try and use the Trim in the correct manner (adjust, quickly click trim and release and release stick to center) the autopilot majorly oversteers, so that if I'd got it lined up straight, it banks left or right and if I was intending to bank, it overbanks and if I was pitching up or down, it goes much further than I wanted. I'm releasing the stick to center as quickly as humanly possible. The only way I've found to avoid this problem is to use the incorrect procedure of holding trim, adjusting pitch/bank, then releasing trim but this comes with it's own problems (i.e. making the helo very sensitive and thus hard to make the required adjustments).

 

2) On a couple of occasions, I've gone into an uncontrollable spin, as if I had my foot stuck on one of the rudder pedals. As far as I'm aware I haven't been damaged at this point (there's certainly no lights on the overhead panel to indicate anything's wrong) but I haven't been able to stabilise from there, as even if I managed to dampen the spin with the opposite pedal and click trim, as soon as I released the rudder it started spinning in the original direction again.

 

A similar problem I had was that I tried to rotate from a hover to point in a different direction and clicked trim but on releasing the stick the helo rotated back to the original point again.

 

Does anyone know what might be causing this and how to deal with it?

[Daniel M]

Biggest help will probably be to post a trk. Specifically if you can duplicate #2. I don't see anything wrong with pressing and holding trim to get the chopper to get to what you want. Though if i know i'm going to be doing a lot of manuevering i'll switch to FD(avoiding/running away crying from sams/aaa). The only other "normal" things I check when trim feels funky to me is to make sure force feedback joystick is disabled, and the center trim option is set how you want in settings. Almost forgot, don't forget to mess with your axis curves if you feel like you can't get enough precision in small movements.

[Shein]

Map "reset trim" to a button on your stick. Or quickly press "cntrl T" i think its left control. Someone correct me if I'm wrong... but reset the trim, and then retrim. That should stop your wild spinning if you trim it the wrong way somehow.

[159th_Viper]

 

Does anyone know what might be causing this and how to deal with it?

 

Trim more often.

 

By that I mean if you are going to make a ten-degree heading change, then you are required to hit the trim tab approximately 10 times for the 10-degree heading, ie one trim per degree.

 

Do not move the cyclic to the 10-degree heading position, hit the trim and then recentre the stick and then assume that the autopilot can cope with the input received without minor deviations that you are experiencing.

 

As regards to the rudder issue, again, trim it out. Apply full rudder opposite to the direction of the spin and hit the trim tab. Repeat until the spin is neutralised. Caused by an accumulation of trim error/input to the rudders.

 

 

Never ever hit the 'Trim Reset' tab - it will kill you faster than a bell clapper in a goose's ass.

[chromium]

I usually prefer a different way, after some years of Ka-50 flights: keep the trim depressed from the start of the turn and release it at the end of the manouver, when stable on the new direction and no side drifts are happening.

 

I don't understand how to operate the trim with "clicks" for a continous turn: after any degree I will have to recenter the Joystick to correct the manouver? Seems to be a strange feelings, But I'll try this way also :)

[doveman]

Biggest help will probably be to post a trk. Specifically if you can duplicate #2. I don't see anything wrong with pressing and holding trim to get the chopper to get to what you want. Though if i know i'm going to be doing a lot of manuevering i'll switch to FD(avoiding/running away crying from sams/aaa). The only other "normal" things I check when trim feels funky to me is to make sure force feedback joystick is disabled, and the center trim option is set how you want in settings. Almost forgot, don't forget to mess with your axis curves if you feel like you can't get enough precision in small movements.

 

Thanks, I'll try and capture it in a trk next time it happens. I've got force feedback disabled and I've tried with the center trim option both on and off. Not sure exactly what that does but it didn't seem to make any difference for me.

 

I probably do need to adjust my axis curves to make it less twitchy when making small adjustments but I'm not sure what I need to do to achieve that. I've just got the the sensitivity on 10 at the moment, as per the advice I received when I asked what to set it to.

[doveman]

Trim more often.

 

By that I mean if you are going to make a ten-degree heading change, then you are required to hit the trim tab approximately 10 times for the 10-degree heading, ie one trim per degree.

 

Do not move the cyclic to the 10-degree heading position, hit the trim and then recentre the stick and then assume that the autopilot can cope with the input received without minor deviations that you are experiencing.

 

As regards to the rudder issue, again, trim it out. Apply full rudder opposite to the direction of the spin and hit the trim tab. Repeat until the spin is neutralised. Caused by an accumulation of trim error/input to the rudders.

 

 

Never ever hit the 'Trim Reset' tab - it will kill you faster than a bell clapper in a goose's ass.

 

OK, thanks. I'll try that. The tricky thing with trimmiing I find is having to quickly release the stick to centre after clicking trim. The only way I can be sure it's centered and I'm not adding extra input is to let go of the stick and having to do that within 0.5 secs (I think it is) of clicking trim is a bit of a dance that probably looks like I've just received an electric shock and having to do that 10 times in a row would look even weirder but maybe I can set a deadzone so that I can keep my hand on the stick without risking adding unwanted input.

 

I certainly wouldn't call them minor deviations though. It seems more like if I'm trying to bank 5 degrees, it ends up banking 10 but I'll see if your suggestions works.

[doveman]

I usually prefer a different way, after some years of Ka-50 flights: keep the trim depressed from the start of the turn and release it at the end of the manouver, when stable on the new direction and no side drifts are happening.

 

I don't understand how to operate the trim with "clicks" for a continous turn: after any degree I will have to recenter the Joystick to correct the manouver? Seems to be a strange feelings, But I'll try this way also :)

 

Yeah, that's what seems to work better for me too but it's not the correct/recommended approach (except for maybe when making major heading adjustments) so I was trying to do it the right way. I'm going to try 159th_Viper's tips though and hopefully I'll get the hang of it :)

[chromium]

I re-read the wonderful IVANK thread about that in my lunch-break (http://forums.eagle.ru/showthread.php?t=36246&highlight=operate+trim&page=1) and after some pages it seems that russian pilots usually work the same way Viper told us, while US pilot seems to work the same way that IVANK and I do.

[doveman]

I re-read the wonderful IVANK thread about that in my lunch-break (http://forums.eagle.ru/showthread.php?t=36246&highlight=operate+trim&page=1) and after some pages it seems that russian pilots usually work the same way Viper told us, while US pilot seems to work the same way that IVANK and I do.

 

Interesting. I guess I'll have to decide whether I want to be a Russian or American pilot ;)

[Ich666]

Recently Ive tried to trim "the russian way", but it doesnt seem to work for me:

It seems to "overshoot" every time i make a maneuver without holding the button down for the whole time. For example: Im turning left to line up the shark with the runway, so once im lined up, neutralizing my left turn with right cyclic and rudder, i blip the trimmer, expecting the helicopter to hold the attitude i just established. But what it does instead, is to yaw right, with the nose slowly pitching down and banking left. I know, since im using a Force Feedback stick that theres some amount of error involved, due to the stick suddenly becoming loose and my hand still applying force to it, but that doesnt explain the movements going on.

 

So my question is: How do real life russians fly the helicopter with constant clicking of the trimmer? Is their stick harder to push, forcing them to make smaller inputs, which are probably handled better by the autopilot? Or is it my Stick having too much force, thus making me "overshoot" my movements?

 

Thanks for any answers, since im very interested in flying "the correct way" and i cant stand the loose stick when i constantly hold down the button.

[doveman]

Recently Ive tried to trim "the russian way", but it doesnt seem to work for me:

It seems to "overshoot" every time i make a maneuver without holding the button down for the whole time. For example: Im turning left to line up the shark with the runway, so once im lined up, neutralizing my left turn with right cyclic and rudder, i blip the trimmer, expecting the helicopter to hold the attitude i just established. But what it does instead, is to yaw right, with the nose slowly pitching down and banking left. I know, since im using a Force Feedback stick that theres some amount of error involved, due to the stick suddenly becoming loose and my hand still applying force to it, but that doesnt explain the movements going on.

 

So my question is: How do real life russians fly the helicopter with constant clicking of the trimmer? Is their stick harder to push, forcing them to make smaller inputs, which are probably handled better by the autopilot? Or is it my Stick having too much force, thus making me "overshoot" my movements?

 

Thanks for any answers, since im very interested in flying "the correct way" and i cant stand the loose stick when i constantly hold down the button.

 

I don't have a FFB stick but that's pretty much the same problems I've been having.

[Ich666]

I don't have a FFB stick but that's pretty much the same problems I've been having.

 

Interesting, that would cancel out all the problems involved with the spring force suddenly disappearing. Does it happen to you with center-spring-trimming ON, too?

[doveman]

Interesting, that would cancel out all the problems involved with the spring force suddenly disappearing. Does it happen to you with center-spring-trimming ON, too?

 

I've tried with the center trim option both on and off and it didn't appear to make any difference. I've always had the FFB option disabled as I don't have a FFB stick.

[doveman]

I've attached a trk showing the problem. For the first half I tried the "correct" trim method of adjusting, then clicking trim and releasing to centre which always seems to result in it overshooting quite considerably where I was aiming for, then just as I was approaching the water I switched to hold trim, adjust, release trim, which seems to always stay at the bank/pitch I had achieved when I released trim.

 

Hopefully you can see from the in-cockpit stick that with the first method I was releasing it to centre immediately after clicking trim.

 

I shut-off the fuel and did a nice big crash at the end, just to make it a bit exciting ;)

Trimming.trk

[Ich666]

I've attached a trk showing the problem. For the first half I tried the "correct" trim method of adjusting, then clicking trim and releasing to centre which always seems to result in it overshooting quite considerably where I was aiming for, then just as I was approaching the water I switched to hold trim, adjust, release trim, which seems to always stay at the bank/pitch I had achieved when I released trim.

 

Hopefully you can see from the in-cockpit stick that with the first method I was releasing it to centre immediately after clicking trim.

 

I shut-off the fuel and did a nice big crash at the end, just to make it a bit exciting ;)

 

I watched the track, thats exactly the same problem Im having. Ive been fiddling around a bit more yesterday, what worked best was to first trim roughly and then slowly fine tuning the newly-set trim. But from what Ive seen in RL footage, most of the time the Pilot only clicks once, the trimmer instantly reengages, and the helicopter doesnt overshoot.

 

So my theory is: somehow ED might have modeled in the effect of the hydraulics disengaging, after which the pilots hand overshoots. This might be realistic for non-force feedback joystick owners, but its not practical to have, since that makes the trimming unneccessarily hard and for those, who have a FFB stick its a double Simulation.

 

The second way this could be explained would be a lack of expertise, which I highly doubt, since Kamov might not be interested in presenting their helicopter in a bad way and ED has proven their Knowledge countless times.

 

Could we have an official word on this, if this is supposed to be that way, or if theres a way to solve it?

[doveman]

I watched the track, thats exactly the same problem Im having. Ive been fiddling around a bit more yesterday, what worked best was to first trim roughly and then slowly fine tuning the newly-set trim. But from what Ive seen in RL footage, most of the time the Pilot only clicks once, the trimmer instantly reengages, and the helicopter doesnt overshoot.

 

So my theory is: somehow ED might have modeled in the effect of the hydraulics disengaging, after which the pilots hand overshoots. This might be realistic for non-force feedback joystick owners, but its not practical to have, since that makes the trimming unneccessarily hard and for those, who have a FFB stick its a double Simulation.

 

Thanks for taking a look at it. It does seem like something's wrong if RL footage shows it being easier to use!

 

I'll try your approach of rough-trimming then fine-tuning but if that's not much easier I'll probably stick with holding trim unless it gets fixed. It's not ideal as this disengages the AP channels, making the helo rather jittery but it's still easier to adjust it to the desired bank/pitch that way than by clicking trim.

[Ich666]

OK, it looks like we're having this Issue: http://forums.eagle.ru/showthread.php?p=1321019#post1321019

 

Its a shame it never got fixed, today I did a quick test in BS 1 and everything worked flawlessly. This is a problem especially for FFB stick users, since your stick gets really loose when you hold down the trimmer and in combination with the bad framerates this leads to everything but a controlled flight.

 

How about fixing this ED?

[doveman]

Hey, good find. I'll repost my track in that thread and perhaps it will get looked at.

[Fishbreath]

I have a non-FFB stick, and I get the same problem. I suspect it's something along these lines:

 

1) I fly the helicopter onto a new attitude, 'fighting' the autopilot to get there.

2) I blip the trimmer.

3) The game logic, rather than holding the new yaw/pitch/bank attitude, holds my new yaw/pitch/bank control inputs.

4) My control inputs are ~20% greater than necessary, because I had to override the autopilot's old attitude hold inputs to get there.

5) The new inputs push the helicopter further in the direction I was maneuvering, because they're stronger than they should be, thanks to #4.

 

Holding the trimmer down disables the attitude hold functionality and gives you something like flight director mode, so you don't get the 'bump' when you fly onto a new attitude and hold it there—the controls are nearly where they should be for the new attitude, so the autopilot's authority is sufficient to hold it. There's another, unrelated jolt I get when I release the trimmer in the middle of dynamic maneuver. That one, I think, is something like this:

 

1) I'm pushing the nose forward, using more control input than necessary to hold the nose at my desired attitude.

2) I release the trimmer.

3) The helicopter jolts to the nose-down attitude where my control input would be stable, rather than attempting to hold the pitch angle attained when the trimmer was released.

 

In short, it seems to me like the trimmer is functioning exactly as a helicopter trimmer should, sans the autopilot (which is to say, I expect it to function like it seems to in Flight Director mode). The problem is, it seems to be functioning in the same way when the attitude hold autopilot is on (when Flight Director mode is disabled)—as a naive system to hold control inputs at their current positions, rather than as a true attitude hold system. I'm not sure if this is how it's supposed to work or not. If it is, I'll just have to stick with the decidedly non-Russian method of holding the trimmer down through maneuvers.

[Ich666]

Thats exactly what was described in the thread i linked and what was supposedly fixed in 1.1.1.1. However it seems to still be a problem, if you tried to trim the russian way youll notice that its nearly impossible in BS2/World, while theres no problem in BS1. From my point of view its working "as intended" in BS1, the helicopter flies much more stable in general.

 

Maybe something with coding knowledge should look into this, its clearly not fixed.

[Chelco]

Nothing helped me more to understand what the trimmer is doing to my Shark than the collective/cyclic indicator that pops out after pressing [RCtrl]+[Enter]

 

Cheers,

[Ich666]

You should probably read the last two pages before posting...

Anyways, Im aware of the fact that we went slightly off-topic, so I suggest we continue here: http://forums.eagle.ru/showthread.php?t=80992&page=13

[Chelco]

To the guy above: Excuse me?

 

To the original poster: maybe your pedals are (unknown to you) trimmed to the left/right and that's why you spin (?).

 

[RCtrl] + [Enter] will show you where your pedals are.

 

Check your PM today or tomorrow. I will be posting something in my blog about this very thing tomorrow morning and I will be thrilled if you could read it.

Edited October 5, 2012 by Chelco
Adding stuff. ESOL.

[doveman]

Sure, I'll look out for that thanks.

 

I was using a mod that disabled the Rtrl+Enter popup but I don't have it installed at the moment since installing 1.2.1 so I'll try that.