I have found the source of the problem and a fix to it. The problem is that 'e' is set as the key-binding for helicopter fast forward, but this can't be found in the control menu at the moment. BIS please either remove 'e' as the default binding or add it to the control menu.

To fix:

1. Go to C:\Users\Yourname\Documents\Arma 3 Alpha - Other Profiles\YourProfileName and open the file called YourProfileName.Arma3AlphaProfile with notepad (Double click the file and choose 'select a program from the list' Then choose a word processor like notepad)
2. Press Control+F or scroll and find the line keyHeliFastForward[]={18};
3. Delete the '18' part or replace the line with this: keyHeliFastForward[]={};
4. Save file
5. Fly helicopters as normal!

Cheers ill give it ago.

Thank god. I thought I was doing something horribly wrong. Thanks for the post, and thanks for the resolution Blue.

Thx Blue, worked for me too !
let´s hope that this gets fixed by BIS too, and not only stay as a "community fix"

Thnx for the fix, really helped me out there.

Hope it gets fixed, because it was pretty confusing.
I double checked my controls 3 times to so what each helicopter control should be doing and then I noticed it was a bug.

Higher voted report of this issue here: #0000727.