Kill Rate

A gameplay element included in Ace Combat 5: The Unsung War, the Kill Bar is, as its name states, a bar that increases as enemy forces are felled. As enemy targets are destroyed, the bar fills. When it's full, the next aircraft in the familiy will be unlocked. For example, filling the KB of the F/A-22A Raptor unlocks the F/B-22 Concept.

A similar concept was featured in Ace Combat X: Skies of Deception, however the kill bar unlocked the current aircraft's next paint scheme.