(a) Special use airspace consists of airspace of defined dimensions
identified by an area on the surface of the earth wherein activities must
be confined because of their nature, or wherein limitations are imposed
upon aircraft operations that are not a part of those activities, or both.
(b) The vertical limits of special use airspace are measured by
designated altitude floors and ceilings expressed as flight levels or as
feet above mean sea level. Unless otherwise specified, the word "to" (an
altitude or flight level) means "to and including" (that altitude or
(c) The horizontal limits of special use airspace are measured by
boundaries described by geographic coordinates or other appropriate
references that clearly define their perimeter.
(d) The period of time during which a designation of special use
airspace is in effect is stated in the designation.