Pilots can Level Up in 2 different ways; by using the vehicles equipped with a Pilot in battle to gain experience, or using the “Boost” feature by spending gold to immediately advance the Pilot a Level.
The better the player performs in battle, the more experience Pilots will gain.
The higher the Pilot’s rank the more experience it requires to level up, as well as costing more gold to boost a level. You can keep track of your progress by looking at Pilot’s experience bar.