Edit the fovTop & fovLeft values to hearts desire (I use 1.03, 1.83, respectively)
Get into a helicopter in first person (I used a pawnee) and go first person, your FOV will be closer to the windscreen.
You should notice a difference, if you don't I'll update this task with comparisons from 1.68 to 1.70
My friend managed to find one from tanoa when he was in a humming bird, his FOV values are the same as the above - https://image.prntscr.com/image/2c3ef40748834e5d88c7ee2537c80eea.png