An Ace is a experienced, talented fighter pilot.
In the world of Crimson Skies, an Ace is an enemy pilot of higher-than average skill, typically identified in-game by name rather than by allegiance and model of their aircraft.
Because of their substantially-higher accuracy, firepower and defenses, Aces should always be the priority target. Aces will always target the player or other Aces in preference of any objective, and should therefore be considered extremely dangerous.
Defeated Aces are marked differently in the Scrapbook, with red ink and a star.