From the Kickstarter Page:
Flying Circus is a roleplaying game about air combat in the early days of flight. The system is designed to capture the thrill and danger of taking an overworked and overloaded aircraft into battle, risking death not just from the enemy but mechanical failure, the elements, or losing control of a rickety and barely understood aircraft.
In other words, you're a traditional fantasy adventurer, but instead of a sword and spells, you have an antique airplane and its rusty machine-guns. And you might still have to fight a dragon.