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The sector system in IvAc 2 will implement the following major changes:
A sector is an indivisible block of airspace which may be activated. Each sector is composed of the following:
<sector id="Y" name="Yellow sector" callsign="Somewhere Radar" freq="125.550" type="acc">
The sector is defined by one of more volumes of airspace.
A volume is a polygon with a upper and lower level that defines the airspace of a particular sector. A sector with 2 different upper/lower levels such as Y sector would have two volumes.
Volumes of separate sectors may overlap and the smallest volume will be considered. Reference to the diagram above, in Y sector there is no need to cut out the APP airspace.