BlenderOne

The curves on top represent the change in sensitivity for the sliders under it. This is similar to controls-settings for RC-helicopters: Less sensitive still allows you to use the full range, but input-controls at the middle have less steering effect and at the extremes have more effect. This allows for better control in the center-area. In RC-terms this is described as 'Expo' or Exponential. Linear controls (straight line) will have the same amount off steering effect over the whole range. You can guess the last one. This video will explain: https://www.youtube.com/watch?v=skU51E5ilG0. The 'V'-setting is in fact a drop-down menu to define the multiplication-factor of the input, which will limit the effective range of motion (RoM) of your controller. With a factor of 2.0 full steering will be reached at 50% motion (2.0 x 50% = 100%). Inputs outside the 50%-circle are not used or 'clipped'. This allows you to use dime-size inputs for full control, especially useful for realistic helicopter-steering. I'll try to add some pictures/graphics later.

Remember to minimize the deadzones of your controls in the advanced settings. When flying with keyboard use 'pulses' instead of keeping the keys pressed. Some background on flying can be found for free at the FAA. See the Helicopter Flying Handbook at https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/helicopter_flying_handbook/ I'm using a Hotas-X and Saitek rudderpedals.

There is a lot of basic information in the free helicopter flying handbook of the FAA. http://www.faa.gov/regulations_policies/handbooks_manuals/aviation/helicopter_flying_handbook/ Especially useful when using the Advanced Helicopter Flying Model (AHFM). Enjoy!

For the advanced helicopter flightmodel you definitely need analog controls. I use a Thrustmaster HOTAS-X which allows you to separate the joystick and throttle. This gives me the option to put the controls on my left and right. The 'click' of the throttle is a bit annoying, but can be removed (voids warranty). Along with the Hotas I use Saitek rudder-pedals.