Trimming the Ka-50

[Acedy]

If you are new to flying the Ka-50 or helicopter simulations in general, you first have to get used to the trimming function. Understanding aircraft trim and its relation to the flight control/autopilot system is absolutely essential for controlling the helicopter, and if you do not use it properly you will fight rather than fly the aircraft.

 

Producer's Note #10 is devoted to trimming the aircraft and can be viewed here:

 

This thread contains a wealth of information about how to trim and use the autopilot, so if you have problems with trimming, please read through this thread. Only add a new post if your question could not be answered. Please do not start new topics about trimming, the moderators will merge them into this thread anyway.

 

Additionally, there are multiple FAQ items related to trimming, which might contain the answer to your problem:

This chopper is insane! It turns every which way except my way!

 

How does the trimmer work and how am I supposed to use it?

 

My trim function is not working. When I hit the trim button and neutralize the joystick, the cyclic in the cockpit also returns to neutral.

 

Having trimmed the helicopter in level flight, when I press the trimmer again, why does it affect the helicopter’s pitch and speed?

 

Why does the helicopter pitch up?

 

For non-FF sticks, it is possible to increase the time provided to neutralize the joystick after trimming the helicopter (i.e. the time between releasing the trim button and the trim setting taking effect)?

 

 

***Note this thread has been compiled from multiple user submitted threads, so the order of posts may not be 100% correct anymore.***

Edited December 23, 2008 by Wags

[Slayer]

Trim

 

I am concerned about the trim function for the Blackshark looking at the thread http://forums.eagle.ru/showthread.php?t=33553

 

I don't have the russian version so I can't confirm this is the exact way it performs but it appears so from the cougar thread and the english manual.

It appears that when you press the trim button while holding the stick in a certain position that it should hold that attitude when the stick is returned to center just like a real helicopter. Unfortunately not everyone owns a cougar or force feedback joystick.

 

From the manual:

 

SPECIAL HARDWERE CONSIDERATIONS FOR CONTROLLING A HELICOPTER Compared to the controls of a real Ka-50, the main difference in this simulation is the need to return the cyclic to a neutral position each time the trim button is activated. In the real aircraft, the cyclic remains in a trimmed position; this is only possible in this simulation if you are using a Force Feedback joystick.

What this seems to mean for people with standard non-force feedback joysticks is that when you hold the stick in an attitude, press the trim button then release the stick the helicopter will yaw back the other way when you release pressure on the stick because it was trimed at its previous position, thereby negating the reason for having trim in the first place???!!!!

 

This is simulated a little to close close to reality for people with non force feedback,non programable, or joysticks with any kind of centering spring return because 99% of joystics are modeled toward aircraft flight controls instead of helicopter cyclic.

 

A simple fix would be to make the game take an initial reading of the stick position when the button is pressed but not react to stick input until the button is released so you could press the button, return stick to center, then release without the helicopter yawing back the othe rway because the center has changed. This way anyone with any stick, programable or not can use trim. On a helicopter the trim button is probably one of the most used buttons of all....

 

I saw a thread for cougar owners with advice on how to implement this via its software, but this is impossible on my X52 Pro or on any non-programable stick. A simple press-hold-release type of setup would be way better that way noone not forced to buy some reduced functionality FF stick and people with lower end joysticks can still take advantage of it.

 

If I'm completly off base with this let me know.....I haven't flown the sime yet....

Edited November 19, 2008 by Slayer

[GGTharos]

You're completely off base. It works are you described.

 

Hit trim, release it, release the stick - your virtual collective is centered where you had it when you let trim go.

[TheMoose]

I don't have the russian version so ...

 

Dawm you.... Where did you get you copy then?

 

Sorry frustrated, I need some BS :detective_2: waiting...:D

Edited November 19, 2008 by TheMoose

[Slayer]

Ok good, it appeared to me like you almost needed FF from Urze's FF demo. Guess I won't make any more stupid posts like this until I get my hands on the game and can speak from experience ;)

[SunDown]

Thanks for the response G. I've been wondering the same thing. Good to hear your take.

Edited November 19, 2008 by SunDown

[GGTharos]

It isn't a stupid question, I think - especially when your choice of controller is brough into question ;)

[TheMoose]

Not my call ;) I just can’t wait to get my hands on it. I feel a left over seeing gents purchasing the Russian version. I have no clue on Russians language so I’m still stuck waiting….

[Slayer]

Dawm you.... Where did you get you copy then?

 

Sorry frustrated, I need some BS :detective_2: waiting...:D

 

I don't have any version :/ just saw the cougar thread then came across that snippet in the download manual that became available today.

 

I feel your pain bro I can't wait to get my hands on it either :pilotfly:

[Kurtz]

Ive read that Couger thread as well, regarding the dolphin diving of the heli after trim input.

Regards the X52 series, has anybody tried creating and advanced macro to delay trim release?

[urze]

sorry if i dident made this clear before:

Wehn i

use a plain none ffb stick you can press and hold the trim button -while holding - bring it back to the spring center - than release the button - and you are fine.

This need a little practice but you have not the above described issue with this methode.

The trim is than put to the neutal position of your x52.

Hope this is understandable. (will edit this post when i get my hands on a normal keybord/display. This post is writen on a iPhone)

[tusler]

It works great

 

I have the russian version and trim works like you say. i am using a 568 Combat stick with Saitek pedals until my x52 arrives. When I am flying and holding the stick forward to get the airspeed i want then I hit trim and imeadiatly let the stick gently return to the spring center. Because the autopilot modes have stabalization also it is possible to complete the evolution without any porpising. The fun comes in when you decending for a landing. I have been incrementally setting trim as I slow down so when I am at a hover the stick is very close to center and I put in my last trim. It works fine, the cougar is probably better but not needed.

[Acedy]

Also check this post on how to use trim properly:

 

The autopilot does a great deal of work just flying straight and level. Having a more effective rudder just means you need more stabilization because it would be affected by smaller forces.

 

In-game and for real, when flying along straight and level, all three modes wld normally be engaged. If you want to make any kind of change, you press the trimmer button, make your adjustment, then release the trimmer button. When the trimmer button is pressed, the stabilisation function of the autopilot is disengaged, until you release the trimmer button, at which time the autopilot goes back to stabilizing the aircraft. For example, you are scooting along but you are out of trim slightly, so you'd press the trimmer button, adjust the pedals, then release the trimmer button. If you adjust the pedals without hitting the trimmer button, the autopilot will try to correct your input and bring the nose back to where it was. Of course, if you have the yaw channel off, you never have any stabilization for yaw. This is probably fine in the game, but it is a real pain in the butt in the real thing (I only have experience with Mi-17, though, not Ka-50 specifically).

 

Basically, anytime you move the controls, you should be hitting the trimmer button: press trimmer, move controls, release trimmer.

 

http://forums.eagle.ru/showpost.php?p=571073&postcount=26

[deltahawk2008]

Covered in the manual which has just come out in English. Trim is going to have to be a reflex action to fly this ac properly. Trim often.

[V1Rotate]

Ok so to fly the Ka50 as it would be in real life we trim a lot and leave the AP channels engaged. But I've seen posts saying you'd get hassle from your instructor if you keep removing heading hold.

 

So, my question is how do they change heading with the ap heading channel engaged?

 

I realise there are several methods, I just wanted to know the correct one. Currently, I have heading hold mapped to my joystick and I will disengage it, yaw/bank around to the new desired heading and then re-engage the heading channel.

[Shisai]

I think it's also done with trimming, you push trim, change your heading, release trim, and the autopilot will then try to hold the new heading

[AlphaOneSix]

I think it's also done with trimming, you push trim, change your heading, release trim, and the autopilot will then try to hold the new heading

 

Exactly, the trimmer button on the cyclic, in addition to removing spring tension from the controls, also interrupts the autopilot. The trimmer button on the cyclic affects three channels: yaw (heading), pitch, and roll (bank). Those three channels are always engaged unless you're training, or the autopilot system is having a malfunction.

 

For the collective, it's the same concept, but it's only one channel (altitude hold) and it uses the collective brake. The collective brake holds the collective in position so it doesn't move if you take your hand off of it, and it also interrupts the altitude hold channel.

 

So let's say you are flying along with your three normal channels engaged (heading, pitch, and bank) but you have the altitude hold channel off. Then you decide you want to speed up the aircraft, so you press your trimmer button on the cyclic, move the cyclic forward to increase airspeed, then release the cyclic. Since the altitude hold channel is not engaged, the aircraft will start to lose altitude, and you will have to manually adjust the collective to stop your descent. If you had the altitude hold channel engaged, then the auopilot would automatically increase the collective pitch to keep you from descending. Note, however, that this is done by the autopilot interfacing directly with the hydraulic servos, so the collective stick in the cockpit will not move.

[V1Rotate]

But if you retrim with slight yaw/ bank, when you release the trim button the autopilot will hold the aircraft in an out of trim condition?? So the ap is just an attitude hold?

 

I fly large fixed wing jets irl so just trying to get my head around how the helo ap/flight director/trimmer is supposed to function... I think I've got it, just trying to relate it to what I know already which is probably a bad thing - as they say, a little bit of knowledge is a dangerous thing!

[Fudd]

Exactly, the trimmer button on the cyclic, in addition to removing spring tension from the controls, also interrupts the autopilot. The trimmer button on the cyclic affects three channels: yaw (heading), pitch, and roll (bank). Those three channels are always engaged unless you're training, or the autopilot system is having a malfunction.

 

For the collective, it's the same concept, but it's only one channel (altitude hold) and it uses the collective brake. The collective brake holds the collective in position so it doesn't move if you take your hand off of it, and it also interrupts the altitude hold channel.

 

So let's say you are flying along with your three normal channels engaged (heading, pitch, and bank) but you have the altitude hold channel off. Then you decide you want to speed up the aircraft, so you press your trimmer button on the cyclic, move the cyclic forward to increase airspeed, then release the cyclic. Since the altitude hold channel is not engaged, the aircraft will start to lose altitude, and you will have to manually adjust the collective to stop your descent. If you had the altitude hold channel engaged, then the auopilot would automatically increase the collective pitch to keep you from descending. Note, however, that this is done by the autopilot interfacing directly with the hydraulic servos, so the collective stick in the cockpit will not move.

 

This is the best post I've seen yet.

 

Its hard to explain it those who have not worked on helicopter flight controls. It isn't a solid mechanical linkage between the stick and the swash plate of the rotor head. It can be with the servos off--but that is less than ideal.

 

Your servos lengthen and shorten their inputs depending on speed, etc and also allow you to auto 'hold' a position in the sky. This is not always seen on the stick side. You can trim your stick to a certain postion, but depending on the flight paramaters of the aircraft, the servo may be continuing to alter its input on the flight control channel.

 

Its uber complicated... and those of you who have ever seen a mixing unit know that channels impact and have input on other channels and even the engine is affected (collective bias)...

Edited November 19, 2008 by Fudd

[Prophet]

sorry if i dident made this clear before:

Wehn i

use a plain none ffb stick you can press and hold the trim button -while holding - bring it back to the spring center - than release the button - and you are fine.

This need a little practice but you have not the above described issue with this methode.

The trim is than put to the neutal position of your x52.

Hope this is understandable. (will edit this post when i get my hands on a normal keybord/display. This post is writen on a iPhone)

 

I will give this a try. I have not been hold the trim until I center the stick.

 

If that is in fact the case, then none of that special scripting and such is needed :thumbup:

[Esac_mirmidon]

Then in conclusion? How is the right procedure to trim correctly?

 

1-Press trim button, hold the button pressed, move the cyclic, release the trim button, recenter the cyclic.

 

2-Press trim button, hold the button pressed, move the cyclic, recenter the cyclic, release the trim button.

[AlphaOneSix]

Then in conclusion? How is the right procedure to trim correctly?

 

1-Press trim button, hold the button pressed, move the cyclic, release the trim button, recenter the cyclic.

 

This one. :)

[ronht]

The issue all along has been about the fact that once the trim button is released, if the joystick isn't centered, input is immediately transfered to the simulation resulting in a pitch, bank or yaw change.

 

Ideally, if you don't have a force feedback stick, you need to -

 

Press the Trim button, (to hold the correction that was being manually input) re-center the joystick, then release the trim button.

 

That way no additional input from the joystick takes place after the trim button is released.

 

Ron

[AlphaOneSix]

But if you retrim with slight yaw/ bank, when you release the trim button the autopilot will hold the aircraft in an out of trim condition?? So the ap is just an attitude hold?

 

Just like in the big aircraft, your controls are not directly connected to the rotors, they are directly connected to hydraulic servos (boosters) which do the heavy lifting (almost impossible to move the controls without hydraulic assist). The autopilot system also connects to the servos. The autopilot has 20% authority over the flight controls, but they interact directly with the servos, so when the autopilot is doing its thing, there is no movement of the controls in the cockpit, it's transparent to the pilot.

 

If you get into the Ka-50, start it up, and for the autopilot, all you do is push in those three autopilot buttons (heading, pitch, and bank; don't do anything with the PVI-800) then all you are really getting is stabilization. So if you push in the trimmer button (which temporarily interrupts the autopilot) then push the aircraft out of trim and release the trimmer button, the autopilot will try to hold that attitude. It's far from perfect, and all it's really trying to do is make it a little easier to fly by damping the controls so you don't have to make continuous, small control adjustments. This is why it is sometimes better to think of the autopilot in its basic form as a stability augmentation system. It want to hep you keep the aircraft going where you point it. If you point it in some odd fashion (i.e. out of trim), it's not the autopilot's job to correct for that, it's job is to assume you know what you're doing (poor assumption in my case!) and help hold that attitude for you.

 

There is also much more to the autopilot. By setting certain modes (e.g. hover and route) via the PVI-800, the autopilot will get instructions from the PVI-800, which will tell the autopilot how to move the controls (again, not the ones in the cockpit, just the control surfaces via the servos) to either keep you in a hover or fly a certain route. This is a more traditional definition of "autopilot", but the autopilot system itself doesn't contain the logic to make the real decisions on what inputs to make, that comes from the PVI-800.

[AlphaOneSix]

Ideally, if you don't have a force feedback stick, you need to -

 

Press the Trim button, (to hold the correction that was being manually input) re-center the joystick, then release the trim button.

 

If I am remembering correctly, you press the trimmer button, make your adjustment, release the trimmer button, THEN let your joystick return to center. The game will pretend that the joystick is still in the position where you let go of the trimmer button.

 

Please someone correct me if I am wrong, as I have not played (I mean TESTED! :P) the game in a while, as I'm currently overseas (but I will be home in a week and back to testing!)