How to Take Cover in Grand Theft Auto (GTA) 5: 6 Steps
After a few hours of testing, these are the controls I found most useful for flying. The plane can be controlled by just your left hand, precise movements are for the mouse.
Car Controls - GTA5-Mods.com
How to Use the Weapon Wheel in GTA V: 6 Steps (with Pictures)
GTA 5 Online Interaction Menu: How To Open & All Options List