While the mouse control works for helicopter control there needs to be a seperate invert vertical mouse option in the settings for helicopters.
The “default” mode in a real aircraft is when you pull the stick or in this case the mouse, the aircraft pitches backward.
With the default mouse settings this is not the case.

You can invert the vertical mouse axis for you character to fix this, but then the vertical axis of your character is inverted.

You really need a seperate invert vertical axis in settings for helo’s!

This is also true for console.