Trim...again.

The subject of trim has truely been beaten to death on this forum. So why try to revive it? Because after 300 + hours flying this sim I've begun to learn something that, although probably immediately obvious to some of you, is only now clear to me. And that is the difference between the function of the trim button with FD on (autopilot off) and FD off (autopilot on). A few months ago, I actually gave up DCS because I hated flying the thing until a forum member suggested using the flight director to bypass the axis hold functions of the autopilot while still benefiting from the dampening functions of the Ka50's stability augmentation. That simple step made flying the sim enjoyable for me and from then on I used the FD exclusively unless I required the "enroute", "autohover", or "turn-on-target" autopilot modes. Still, I wanted to do it the "right way" and follow the lead of GG, Wags, EB1 and other DCS Pros. So I decided to do the entire Chapter 3 of the oil campaign with the Autopilot ON (FD not engaged). Alas here is what finally sank in to my thick old skull:

With the FD off (autopilot on) the trim button doesn't just trim, it also commands a new pitch, roll, and yaw axis for the autopilot to hold. And the autopilot will do just that (to the extent of its control authority) even as conditions change. For instance, if the pilot has the helo trimmed slightly nose down and accelerating through 100 kph, the flight control system will hold that attitude even as the airspeed continues to increase and, unknown to the pilot, trim is required. In this example if the pilot presses the trim button (with a non-ffb stick) the helicopter will immediately pitch up. I took this to be an error with the the way the Ka50 was modelled in DCS when actually the error is in my use of a non-ffb stick. The reason I didn't have this problem with the flight director engaged is because I was intuitively adding forward cyclic as the speed increased. Therefore pressing the trim button changed nothing (while releasing the button held the cyclic in the new trimmed position and I no longer needed to hold that pressure.) With this simple knowledge, flying and agressively manuevering with the autopilot on became easier but did require that I hold the trim while maneuvering, sometimes for long periods of time. Once the trim is released, the FCS "thinks" that the pilot is commanding an attitude hold which of course is rarely the case when maneuvering. The technique therefore becomes something like: manuever, trim then trim-and-hold (the first press of the trim...well...trims, while the second press allows for throwing the helo around without the autopilot attempting to hold an axis). Now I'm not completely stupid. I've read the manual a dozen times, I've watched all of Wag's tutorials and I've read everything the experts on this forum had to say on the subject. It's not that I didn't know from the beginning that holding the trim button would allow for easier maneuvering, it's that I didn't really understand why. I felt that Kamov would never build a helicopter where the autopilot is always on until the pilot holds the trim. To a professional fixed-wing pilot, it just didn't seem logical or intuitive. Now it seems more of both.

Armed with this new understanding, do I keep the FD off? No, I've gone back to my old way of flying because I've found the press-and-hold step to be a little combersome when the LWS is flashing and tracers are flying past the canopy. But I do now understand why most keep the FD off and fly the way they've been told is proper--because it works. In the end, flying FD on or off is, as we say in the south, "six of one a half-dozen of the other". It is a matter of preference.

Smokin' Hole

Nice read there, ericinexile.

I am still new to the sim, and what you wrote is a good way of seeing it. Helped me understand that aspect of the Shark better.

What also helped a lot in this regard was reading in the FAQ that the system takes a snapshot of the current controler input each time you release the trimmer.

On a side-note, I also prefer to fly with the FD on when lots of course changing is required, i.e. when setting up for targeting, etc. Dully waypoint to waypoint flying is far more convenient with the aid of the APs, controlling alt with the collective.

Cheers,

Rainer

I found this system very hard to get my head around, finally have but wish this explanation was available 2 weeks ago

++ ericinexile, nice explanation.

When I first started, I was told never to touch the 3 APs or the FD (as rl BS pilots are taught), so that's how I learnt how to fly.

Now I don't find holding the trimmer while maneuvering cumbersome at all. It's become so second nature that it's almost a reflex action. I have no issues with hard evasive maneuvers either.

Actually I came to the same conclusion after training a bit with a squad mate and now I fly almost exclusively with the Flight Director turned on. In fact I used to turn off the FD when I wanted to engage autohover, but then I did a mission that had a high cross wind and turning on the autohover was darn near suicidal, so I just hovered by hand. Sure it was not perfect but I was not about to spin into the ground either. :)

I remapped my trim button on my joystick to make holding trim easy and now fly like this as it is the way real pilots do. Takes some getting used to but then becomes easier than switching FD on and off.

I've tried both way but find it easier to fly with the FD on and AP on, and trun off the FD (being careful of the spin effect) prior to going into auto hover, both ways seem to have their pros and cons. I waiting for the changes in the forthcoming patch before making a final verdict.

I've tried it various ways. Tried holding the trim during turns and such but considering I don't have rudder pedals it's a royal pain to both hold the trim (which is my pinky finger on the Saitek) and twist the joystick at the same time. It works, but its certainly not the optimal way to fly.

I've tried mapping the Heading Hold AP button to a button on the stick and turn that off when I want to disable the heading hold. This is the way I've been doing it up until now mostly. This tends to work ok but does end up in some wobble while it's off, which is certainly not good during fixed-weapon employment (rockets etc)

Tried using the FD now that I have a better understanding of its function. I think this is the way I'm going in the future. Probably will remap the current button which is for Heading Hold and switch it to FD and just leave Heading Hold on from now on. Now, instead of turning HH off will just turn FD on. Won't be battling the autopilot for yaw/turn command and will still have the dampening to avoid the wobblies.

Yeah ok ... may not be how the real pilots do it ... but the odds I'm ever going to get my hands on a REAL Ka-50 are exactly ..... ?

I'll go with what works best. :)

Yeah ok ... may not be how the real pilots do it ... but the odds I'm ever going to get my hands on a REAL Ka-50 are exactly ..... ?

 

I'll go with what works best. :)

You're missing the whole point of a study sim if this is how you view simulations.

What are the chances that any of us will get into a real F-16 Or for that matter pilot a real jumbo? Fire a real tank? Drive a real nascar?

To some, the whole point of a simulation is to get as close to the real thing as is possible given the confines of your pc, and your everyday surroundings. Of course we can't all build our home cockpits, but one small way of making up for this is to emulate what would happen in real life.

In the end though, it is a game. So play it how you want to and what's fun for you, but you can't dismiss the point of a simulation.

While what you say is true in part you still must work within the stiff limitations of your environment. The real Ka50 FCS was never designed with the X52 in mind. Watch the split screen demo video (not the cool Frazier track but the real video). I don't recall ever seeing the pilot press and hold the trim. He didn't need to because he was working with the real cyclic attached to real actuators which are in turn attached to real AP servos. By using the FD or by holding the trim, WE are overcoming our limitations to achieve as best we can HIS controllability. That's the ultimate use of a "study sim" IMO.

Smokin' Hole

*points to Ericinexile* Yeah. What he said. I am mimicing the performance of the AIRCRAFT operation as much as possible vs the actions the pilot is taking.

Though as far as the trim issue is concerned ... I wonder if Saitek has ever given thought to making a force feedback model?

*points to Ericinexile* Yeah. What he said. I am mimicing the performance of the AIRCRAFT operation as much as possible vs the actions the pilot is taking.

 

Though as far as the trim issue is concerned ... I wonder if Saitek has ever given thought to making a force feedback model?

Well you can mimic what rl pilots do as well to get that performance from the BS.

I think a lot of continued confusion remains because of the descrepancy between the way producer video notes #10 ( Understanding aircraft trim ) explains the use of trim in the BS with a non-ff stick and the way it is most often described on this forum. In the video, near the end, he says "by no means do you need to be holding down the trimmer button when you do any kind of maneuver", yet in this forum most advice says the correct way to trim is to hold the trim during maneuvers. As most of you know, unless you hold down the trimmer button while maneuvering, the KA-50 will fight you the whole way.

Though as far as the trim issue is concerned ... I wonder if Saitek has ever given thought to making a force feedback model?

how about a twin throttle while the're about it....:joystick:

Why no simple pitch trim on a hat switch?

Hi everyone. I'm newly registered on the forum but have been following this awesome sim for some time now. Haven't got it yet myself as I'm saving up to buy a new PC - my current clunker would choke on this sim.. lol

I have a private helicopter licence and I'm a keen helicopter buff. I don't get to fly much for real but I fly alot in X-Plane and I know a fair bit about modern civil helos.

The trim method in Black Shark seems to be very strange and overly linked to the autopilot systems. Perhaps this is true to life in the real Black Shark, but I can't help wondering why you can't assign "Pitch trim up/down" to a hat switch and use it incrementally as required - which is how its done in the vast majority of helicopters that I know about. Push the hat forward in stages when transitioning from hover to cruise - pull it back in stages when transitioning from cruise back to hover. Very simple to use and very effective.

Due to the twin coaxial main rotors and the absence of a tail rotor, one shouldn't really need trim in roll and yaw axis in regular flight. Pitch trim would do fine for most cases. Autohover will take care of any crosswinds if you use it when engaging targets.

Since this is a "study sim" and acurately modelled in every detail I'm assuming that the real Black Shark does not have a hat switch for trim? It is not evident in the pictures of the cyclic in the flight manual anyway. Seems strange that they would choose such a seemingly complicated trim system on an aircraft where the pilot workload is already pretty heavy.

Can anyone clarify this for me please? Its all a bit weird.

The Black Shark does not have a hat switch for trim. Incidentally, neither does the AH-64 (whose trim implementation is nearly identical to the Ka-50).

While I'll disagree with ericinexile in principle (you should fly with FD OFF! :D ) I'll agree based on a technicality, the exact same one he mentioned:

The trim system is designed for an FFB stick (to keep things simple), which is exactly how the real thing works. You move the stick, you trim, it stays there.

It's a touch more complicated: It zeroes the forces on the stick in that position. The farther you move the stick from that position the more force you must use.

In this respect, the preferred method to fly is short move, trim. You don't need to hold the trimmer down at all, just move, trim, move, trim, move, trim.

This is most realistically accomplished using an FFB stick.

Celo63, this system is far, FAR simpler and more intuitive than a trim hat, and it is what most heavy helis use to my knowlege - further most such helis tend to have some form of attitude hold system tied to the trim system as well, including several civilian ones. Further, yes, you do have to make significant roll and yaw input changes as flight conditions change. Velocity changes for the shark can be very large.

Basically, you might feel like you're better off with FD ON unless you have an FFB stick. Technically, this is true - this sim is best flown using equipment that resembles the real thing.

I've found since the latest patch a bug where when I push the trim button it locks the controls and I'm unable to control the KA50. I pushed the trim button several times and the stick remained unmovable I'm using a Cougar Hotas.:doh:

You haven't found any sort of bug ... search the forum for the new trimmer logic. ;)

I've found since the latest patch a bug where when I push the trim button it locks the controls and I'm unable to control the KA50. I pushed the trim button several times and the stick remained unmovable I'm using a Cougar Hotas.:doh:

Really, you should read the readme files... New trimmer logic blocks input until you return ALL control axis to zero position. If it's too complicated for you - just use old trimmer.

Really, you should read the readme files... New trimmer logic blocks input until you return ALL control axis to zero position. If it's too complicated for you - just use old trimmer.

What the Read-Me fails to specify/take into account is the penalty for not doing so within the parameter variables specified in the FMOptions.lua file.

Also not evident on which equipment this was tested, further vindicated by the 'solutions' and differing values found post-patch to counter the 'problem' encountered. Each setup is different and accordingly need the values tweaked accordingly for the new trimmer logic to function properly.

In addition, another solution is to change the relevant Forcefeedback value from 'true' to 'false' in setups with Non-Forcefeedback sticks........another fact not expressly mentioned in the Read-Me pertaining to this specific issue.

So..........it is neither a matter of not reading the Read-Me nor being too complicated (not nice being condescending ;)), but rather not enough pertinent Information, especially if one has not had the benefit of testing for months prior to Patch-Release........IMHO of course :)

I've found since the latest patch a bug where when I push the trim button it locks the controls and I'm unable to control the KA50. I pushed the trim button several times and the stick remained unmovable I'm using a Cougar Hotas.:doh:

See the following post:

http://forums.eagle.ru/showpost.php?p=732128&postcount=3

Helped with my Cougar - had the same issues. Also a value relating to Forcefeedback in the Ka-50/Config/Producer.CFG file. Not sure if necessary in the case of a Cougar, but helped for some if 'ForceFeedbackEnabled' is toggled from 'True' to 'False'.

Thanks for the info guys. Much appreciated. Clears that up a good bit but I'll still have to get the sim and play around with it before I can fully get to grips. I'm hoping it won't be too long before I'm up and running.

GGTharos - I'm more familiar with lighter civilian helos I must admit. Ones that don't have any kind of autopilot systems installed. They tend to use hat switch for trim I believe. I'm assuming that once a full multi-axis autopilot system is in place along with the stabilisation and hold functions, this other type of trim system becomes neccessary to cover all situations? Seems logical in that respect.

I'm interested to find out if most people with FFB sticks use trim and those with non-FFB sticks don't use it as much, if at all? I built a flight chair a while ago using an old Saitek Cyborg as a donor stick - chopped it into bits, extended wiring to get cyclic and collective in the right places and lengthened the cyclic a bit. As such I removed all springing from the cyclic so essentially I have no forces on my cyclic at all. Works great for a cheapo flight chair though and its so nice to have all controls in their proper places (I got CH Pro pedals as well). Couldn't go back to a regular stick on the desktop.

I'm assuming that with this setup I'll not have to use trim much, if at all? I like to fly manually most of the time anyway as thats the fun part really. I'd only consider auto hover for engaging targets perhaps, if even then. Again, I'll have to get the sim first and get my teeth into it before I know for sure. Looking forward to the day...

GGTharos - I'm more familiar with lighter civilian helos I must admit. Ones that don't have any kind of autopilot systems installed. They tend to use hat switch for trim I believe. I'm assuming that once a full multi-axis autopilot system is in place along with the stabilisation and hold functions, this other type of trim system becomes neccessary to cover all situations? Seems logical in that respect.

I'm not faimiliar with the specfics of the implementation of those systems so I will make a guess here: A hat switch might actually be cheaper, and lighter in terms of implementations, and perhaps easier to maintaint even than using a cyclic-hold system like on the Ka-50.

The Ka-50 system however, IMHO, IS better and more intuitive than a hat system, even if you don't have an autopilot.

I'm interested to find out if most people with FFB sticks use trim and those with non-FFB sticks don't use it as much, if at all? I built a flight chaira while ago using an old Saitek Cyborg as a donor stick - chopped it into bits, extended wiring to get cyclic and collective in the right places and lengthened the cyclic a bit. As such I removed all springing from the cyclic so essentially I have no forces on my cyclic at all. Works great for a cheapo flight chair though and its so nice to have all controls in their proper places (I got CH Pro pedals as well). Couldn't go back to a regular stick on the desktop.

Unless you really want to feel the pain (And of course, depending on which stick you have), you need to trim often regardless of which you use.

I'm assuming that with this setup I'll not have to use trim much, if at all? I like to fly manually most of the time anyway as thats the fun part really. I'd only consider auto hover for engaging targets perhaps, if even then. Again, I'll have to get the sim first and get my teeth into it before I know for sure. Looking forward to the day...

If you're not using trim you're not doing it right, that's all I can say. ;)

I suppose though this is a fundamental difference from a real chopper: You have to use some amount of force to hold the stick in a given position. Trim takes this burden away. If your stick is really easy to move around, you might feel like you don't need trim.

Bad habit. (Unless your stick naturally stays where you left it if you take your hands off it ... then ... good stick :D )

Really, you should read the readme files... New trimmer logic blocks input until you return ALL control axis to zero position. If it's too complicated for you - just use old trimmer.

I tried centering controls at the time in both situations I'm looking closely at the trim and autopilot now to find the ideal way to fly it. I think we need a real Ka50 pilot to speak up and show us how he does it.:D

Ok what AP modes are on when you fly and whats your method?