Way higher shutter speed, especially from a helicopter which vibrates more than a plane. 1/2000 min and go higher if light allows. A couple of stops from wide open and just have your bum in contact with the helicopter, nothing else. Shooting through glass is not ideal but I assume you'll have no choice.
Summary, key thing is high shutter speed, with aperture wide but not so wide you're getting softer images, tweak iso if needed to keep shutter speed high. You can go pretty high with the 5DIII.
If you tape the focus of the lens to infinity don't use the infinity mark. Actually focus on something in the distance and tape the lens at that point. It'll probably be a small distance before the mark.
I use the 5DIII and 24-70. The 16-35 is a bit too wide. I also use the auto focus rather than tape at infinity because it works well.