trim & hover

[davedontmind]

I'm pretty new to BS2, and am currently trying to figure out how to fly this thing. I've got the basics figured out (especially the crashing - I'm almost an expert at that!), but I've just been trying to figure out the trim & auto hover.

 

After watching a video on the topic of trim, I was pretty confident I'd got it all figured out, but my experience isn't matching my expectations.

 

When I try a test flight, I apply a little collective until I start to rise, and notice the nose pulls up, so I add some forward on the cyclic to balance it, apply some more collective until I'm a reasonable hight above the airfield, then reduce collective until I'm at a steady altitude. At this point I'm still pushing forward on the cyclic to keep it level.

 

As I understood it, pressing & releasing the trim button tells the helo that the position I have my stick in at release time is the new neutral position, so if I hit the trim at this point I'd expect that when I release my joystick back to center, the helo would behave as if I've still got it pushed forward a little, so it would be balanced still.

 

But what seems to happen is that when I release the stick, the nose pulls up to about 8 degrees on the HUD pitch ladder and we start moving backwards.

 

Similarly, if I hit the auto hover button, the nose comes up and we start moving backwards.

 

And on a possibly related issue, I notice that when I've lifted off the runway, if I move the stick so that the pitch is 0 on the HUD pitch ladder, it looks like the nose is somewhat down, and the helo accelerates forward.

 

What am I doing/understanding wrong?

[159th_Viper]

Trim for small attitude adjustments, ie for a ten degree climb you'll trim 5-10 times as opposed to putting the helo in a 10 degree climb attitude and trim thereafter. In the absence of a track difficult to comment any further on technique :)

[ShuRugal]

the mast of the helicopter is tilted forwards about 5 degrees, so to hover, you need about 5 degrees nose-up pitch.

 

The auto-hover function will also try to maintain the position you were at when it was activated. You can change this position by blipping the trimmer.

 

Another thing to do is to hold the trimmer down from before liftoff until you achieve a hover, then release, then set auto-hover.

 

The trimmer switch has two functions at once: the first is to center the stick wherever it is when you release it, and the second is to tell the autopilot that the current flight parameters (pitch, bank, yaw, and velocity) are desireable.

If you just blip the trimmer as you pass the desired flight state (which i have seen many people do) you will end up with the stick centered in the wrong position for the flight state you desire. The autopilot will get the correct snapshot of what you want, but since it can only command a 20% input, having the stick centered in even slightly the wrong spot will degrade performance.

 

The best thing to do to take off into a hover is this:

 

 

1. apply a slight forward pressure on the stick and trim it there (stick on screen should move forward no more than 1-2 inches) so that you aren't trimmed to do back-flips.
   
2. Set the parking brake so you won't roll with your new forwards trim.
   
3. hold the trimmer
   
4. slowly add collective until the nose begins to rise (if you begin rolling before you rise, forward trim on step 1 was too great)
   
5. lift the nose to 5 degrees above the horizon
   
6. continue adding collective until you are off the ground
   
7. achieve a stable hover
   
8. release the trimmer
   
9. activate the auto hover
   
10. re-trim as needed to maintain desired position.
    

In addition to what i mentioned above about how the trimmer button works, there is one more thing important to remember: holding the trimmer overrides the autopilot. So, if you move the stick without holding the trimmer, the autopilot will actively fight you to put the helicopter back where it was when you last released the trimmer. If you move the stick, blip the trimmer, then release the stick, your new center position will be wrong because you were fighting the autopilot when you set it.

 

 

when making any major change in flight (takeoff, land, transition to hover, transition to FF, change heading) you need to hold the trimmer from before you begin the maneuver until after you complete it. If you do this, you will do well with the Shark and you will enjoy flying it. If you do not do this, you will spend your flight sessions fighting the autopilot and constantly over-correcting.

[PeterP]

So here comes my "standard Ka-50 newbie reply" :

 

 

First download Bigfoots interactive training missions

>>> KA-50 Black Shark 2 Training missions

 

 

Read also besides the manual this:

DCS: Black Shark...

Technical, Simplified

-Coaxial Rotor Aerodynamics

-Trimming the Ka-50 Black Shark <<<!!!! very important to understand this fully!

-Part 1 - Autopilot <<<this too!

-Part 2 - Autopilot

 

 

And when you still have time , read this too:

A Stick and Rudder Man's Guide

to DCS: Black Shark

 

Here is a useful tweak if you using real rudders:

How to unchain the rudder from trim - solution

 

Things you want to have some day too:

 

KA-50 collective: another picture-tale

 

Two MS FFB2 with Cougar Grip

 

Welcome aboard!

[AlphaOneSix]

And on a possibly related issue, I notice that when I've lifted off the runway, if I move the stick so that the pitch is 0 on the HUD pitch ladder, it looks like the nose is somewhat down, and the helo accelerates forward.

 

Well this one is easy to answer. The rotor mast is on a 4.5 (maybe 5) degree tilt relative to the aircraft's waterline. If you look at the aircraft on the ground, you can see that the rotor mast tilts forward on the ground. To hover, your rotor mast must be straight up and down (assuming a no-wind condition and that your aircraft is within it's proper center of gravity range). SO in a hover in the game, your nose will up 4.5 or 5 degrees. Personally, I just line up the aircraft symbol with the 5 degree line on the pitch ladder AFTER I've established a stable hover.

 

As far as the nose pitching up when trimming, I'll get back to you on that.

[lokitexas]

Is there suppose to be no force feedback (MSFF2) when you press and hold the trimmer? Its hard to "feel" what the aircraft is doing when I hold it to make adjustments.

 

I have already reverse the axis but it goes limp when the button is pressed.

[pixelpilot]

the force feedback goes limp so you can centre the stick but without a centering spring this can feel very odd, i actually ditched my ffb stick because of this way back when i had the original Blackshark. I havn't tried ffb with the newer versions of Blackshark though.

[JG14_Smil]

One trick to flying the BS is to push and hold trimmer until helo acts like you want, then release.

 

To hover is simple.

 

ALT ENTER - you will see your controls. There is a 'position' the your controls need to be at to hover. It may depend on wind. Use the trimmer and controls to move the pippers to the 'hover position' as you slow the helo.

 

Slowly toggle HOVER button as your speed slows to a stop and you acheive hover position for controls as the speed drops to '0'. Bam!... perfect hover.

[lokitexas]

the force feedback goes limp so you can centre the stick but without a centering spring this can feel very odd, i actually ditched my ffb stick because of this way back when i had the original Blackshark. I havn't tried ffb with the newer versions of Blackshark though.

 

 

Well the FF feels great and it would be hard to give up. I wish it wouldnt go limp though. The only thing I found do is turn on/off heading hold when moving aorund.

[sjpateys]

trimming for a hover is the easiest thing in the world when you know how.

 

1) perform start sequence, allowing rotors to fully spool up.

2) push joystick forward 2/3 degrees, press trim and release stick. ( this stops the pitch up tendency when in default trim).

3) slowly increase collective until heli becomes light on wheels.

4) observe heli behaviour, and push/pull stick forwards/backwards slightly until ASI reads zero, retrim and centre stick.

5) press Auotohover, press trim again and center stick. job done.

 

I fought with the heli for ages until realising how simple it really is. the secret is being gentle on the stick/ retrimming BUT MOST IMPORTANTLY MAKE SURE YOUR FRAME RATE IS REASONABLE. It must be at least 25FPS or so to trim properly. (press ctrl-break to show frame rate).

[sjpateys]

P.S.

I have an 8-core AMD processor, 8Ghz RAM and a GTX 550Ti G Card and I have to run the game on medium settings to get a reasonable (25-40FPS).

I would love to know why!

 

( I tried tweaking system/card settings) has made no difference. Strangely BS1 is no better or perhaps worse.

[sjpateys]

I can fun rise of flight on max settings as smooth as silk, so don't tell me my system is lacking in any way!

[lokitexas]

I can fun rise of flight on max settings as smooth as silk, so don't tell me my system is lacking in any way!

 

 

RoF can be run pretty high on a modest system with a decent processor. I ran it for a while before I upgraded with everything on high except supersample and ground to medium with a q6600 oc'd to 3.0, and 8800gts.

 

My system is similar to yours with i5 3570k, 8gig, and gtx560ti (2gig). I have everything high in BS2 with supersampling to 4x 16Qsaa AA, and 8x Anti, on 1920x1080 with no issues. Not sure why you have have issues.

Edited July 26, 2012 by lokitexas

[sjpateys]

could it be having an AMD processor?

[ShuRugal]

P.S.

I have an 8-core AMD processor, 8Ghz RAM and a GTX 550Ti G Card and I have to run the game on medium settings to get a reasonable (25-40FPS).

I would love to know why!

 

 

Because the graphics engine is a great big cow. Wastes resources drawing things that are too small to see due to the distance (there really is no point in drawing a platoon of tanks five miles away on the main viewport, but the engine does it anyway). Also, weather effects (clouds, rain, fog) are fixed at high-detail rendering. There are a crapton of video resources thrown at making everything look photorealistic, which on one hand is very nice since so few high-fidelity simulators do this, but on the other hand causes lots of trouble for anyone who doesn't have two or three graphics cards.

 

The game also bottlenecks on CPU for some people because it is not optimized for true multi-threaded processing. Those eight cores you have? seven of them aren't doing shit when DCS is running.

[Cowboy10uk]

Well this one is easy to answer. The rotor mast is on a 4.5 (maybe 5) degree tilt relative to the aircraft's waterline. If you look at the aircraft on the ground, you can see that the rotor mast tilts forward on the ground. To hover, your rotor mast must be straight up and down (assuming a no-wind condition and that your aircraft is within it's proper center of gravity range). SO in a hover in the game, your nose will up 4.5 or 5 degrees. Personally, I just line up the aircraft symbol with the 5 degree line on the pitch ladder AFTER I've established a stable hover.

 

As far as the nose pitching up when trimming, I'll get back to you on that.

 

 

WOW, been flying this for years and it never clicked that the mast was 5 degrees off centre. :doh:

 

Think I've just had that eureka moment, why I struggle to keep the darn thing in a stable hover, I'm always trimming at 0 bar.

 

No excuse, I have been on this forum for years, flying bs since it became available in Russia and have the manual in PDF and even purchased the proper manual paperback when it came out a few years ago.

 

What an idiot. :doh:

 

Thankyou guys.

 

 

Cowboy10uk