Definition
A type of special use airspace extending from 3 nautical miles outward from the coast of the United States, containing activity that may be hazardous to nonparticipating aircraft. Warning areas may be located over domestic or international waters or both, and exist to warn pilots of the potential danger. Unlike Restricted Areas, the airspace is not under exclusive U.S. jurisdiction, so flight is not legally prohibited, but it is strongly discouraged when the area is active.
Plain English
A patch of airspace off the U.S. coast where dangerous activity, such as military exercises, may be happening. You are not banned from flying through it, but you are warned that it may be unsafe.
Context Anchor
Seen on aeronautical charts and during route planning, especially near coastal areas.
Derivation
The name is literal — the airspace exists to warn pilots of hazards. It is distinct from a Restricted Area because the U.S. cannot legally restrict airspace beyond 3 NM from its coast, so the FAA issues a warning rather than a prohibition.
Why Pilots Care
Pilots must check charts and may need to reroute or maintain extra vigilance to avoid entering active hazardous operations.
Intuition Check
A Warning Area does not mean any place where a warning has been issued, and it does not automatically mean entry is prohibited. In FAA use, it means a specific charted offshore airspace area where hazardous activity may be present.
Example Sentence 1
The pilot checked the chart and saw that Warning Area W-122 was active, so she requested a routing that kept her clear of it.
Example Sentence 2
During the preflight briefing, the instructor pointed out the active Warning Area and advised staying well clear until the exercise ended.