HQ PACAF A4 (U.S. Air Force) The HQ PACAF A4, or Headquarters Pacific Air Forces A-4, refers to a model of the A-4 Skyhawk aircraft operated by the United States Air Force’s Pacific Air Forces (PACAF). This particular variant was primarily used during the Vietnam War era. Notable for its versatility and agility, the A-4 Skyhawk was designed as a compact, single-seat, subsonic attack aircraft. The HQ PACAF A4 specifically served in various roles within the Pacific region under the command of the United States Air Force’s Pacific Air Forces. The A-4 Skyhawk’s successful service record spanned over four decades, with multiple variants being produced and used by numerous air forces worldwide, making it one of the most widely used attack aircraft in history.