High Value Airborne Asset Protection. An Air-to-air. An aerial fight between two or more aircraft. mission where fighters actively defend an aircraft that is unable to defend itself. Could be a standalone mission or in conjunction with Offensive Counter Air. An A/A mission where fighters preemptively seek aerial engagements with an adversary, typically over their territory. or Defensive Counter Air. An A/A mission where fighters reactively engage an adversary, typically over neutral or friendly territory, in the defense of some protected asset(s). missions.