AIM Text
A warning area is airspace of defined dimensions, extending from three nautical miles outward from the coast of the U.S., that contains activity that may be hazardous to nonparticipating aircraft. The purpose of such warning areas is to warn nonparticipating pilots of the potential danger. A warning area may be located over domestic or international waters or both.
Source: FAA Aeronautical Information Manual · current edition · paragraph 3-4-4.
Research Notes
AIM 3-4-4 covers Warning Areas — special use airspace over international waters.
Warning area characteristics:
- Established at least 3 NM from the coast (international airspace)
- Similar activities to restricted areas: gunnery, missile testing, military training
- FAA cannot prohibit civilian operations in international airspace, so they're "warned" rather than "restricted"
Operations: Civilian aircraft can fly through warning areas. Strongly recommended to avoid when active.
Reference: AIM 3-4-4.