Yeah, a good suggestion... some orders that spring to mind for air units:
Extended patrol - patrol any enemy units within the current unit range (current airfield)
Evade - Patrol, but get back to base (or, a different patrol location?) when any enemy plane circles overlap
Destroy - pick an enemy unit, patrol it (and change position as it moves) until it is dead, then return to base
Save - change base when it is about to be overrun
