Aeronautical facility means, for the purposes of this subpart, a
communications facility where flight plans or position reports are
normally filed during flight operations.
Air defense identification zone (ADIZ) means an area of airspace
over land or water in which the ready identification, location, and
control of civil aircraft is required in the interest of national
security.
Defense area means any airspace of the contiguous United States
that is not an ADIZ in which the control of aircraft is required for
reasons of national security.
Defense visual flight rules (DVFR) flight means, for the
purposes of this subpart, a flight within an ADIZ conducted by a civil
aircraft under the visual flight rules in part 91 of this title.