In ground vehicles, the vehicle commander is the heart of the vehicle. They are your team leader. Obey their orders on where to move, when to fire, etc. Your commander will spot and ID targets, relay specific information about these targets, and provide you with orders. In the event that there is no commander, the driver will inherit these responsibilities.
The commander can issue fire commands (Fire/Suppress)
As a gunner operating independently in any ground vehicle, know the rules of engagement. They are as follows: Hold fire, return fire, and fire at will. Your commander will tell you which rule to observe.
In an attack helicopter, always observe the return fire rule unless explicitly ordered otherwise.
As pilot or crewman, always carry one toolkit from the arsenal in your inventory, and leave one in the inventory of your vehicle. If necessary, carry additional tracks in the inventory of your vehicle.
If driving in a column or other formation, maintain a safe following distance of three vehicle lengths.