In completion of the Missions, I discovered a little secret that enables better SA (Situational Awareness)in helicopter flight, and I don't recall anybody else making this suggestion regarding choppers.
Suggestion: Press [A] till you get the 2D cockpit view. Press [W] till you get just the dials on the bottom of the screen. Now in that mode you can sense every little motion and rock of the chopper, and a quick response is made possible.
In 3D cockpit mode it is impossible to pick up every little movement of the helicopter.
BTW - in the Mission "Oil Rig Transport" , is it possible to collect all three individuals? I have only collected one of them, but still rewarded with success.