Implacable was the name given to an EF76 Nebulon-B escort frigate used by the Imperial Navy in a TIE/IN interceptor simulator mission. The mission objectives were to destroy a Rebel supply base to draw the light Mon Calamari Cruiser Ardent into an ambush. Implacable would drop out of hyperspace before the supply depot and launch TIE Interceptors and TIE/sa bombers. The bombers would attack the space station AZ 77, while the interceptors would engage the Z-95 Headhunters that were defending the depot. When the Ardent arrived, the same Imperial forces would engage it as well.