ADIZ (Air Defense Identification Zone)

An ADIZ is established unilaterally by a state to give its air-defense system time to identify, locate and respond to aircraft approaching its territory. Within the zone, aircraft are typically required to file a flight plan, maintain two-way radio contact, operate a transponder and report position at defined points. Failure to comply can prompt interception by military aircraft, even when the aircraft never enters sovereign airspace.

Crucially, an ADIZ is not the same as sovereign or territorial airspace. A state may extend an ADIZ over the high seas, where it has no right to prohibit overflight, because the requirement is one of identification rather than permission to be there. This distinction can become contentious where ADIZs overlap or are declared over disputed areas, turning an ostensibly administrative measure into a geopolitical signal.

Because ADIZ procedures and boundaries bear directly on how a flight must be planned and conducted near tense regions, they are a recurring factor in route risk. AeroVigil treats ADIZ activations, expansions and disputes as airspace-risk signals, relating them to the routes and regions where identification requirements and interception risk would apply.