Alert fighters
From Battlestar Wiki, the free, open content Battlestar Galactica encyclopedia and episode guide
Alert Fighters are a group of Vipers "standing by" within a battlestar's launch tubes with their pilots in or very near their cockpits in preparation for a quick launch, and are analogous to modern day "alert five" aircraft.
The purpose of Alert Fighters are to support a Combat Air Patrol with the intercept or elimination of any incoming enemy threat.