Section 16.100  Circling Approach Surface

a)         A circling approach surface is a circular area that is 200 feet above natural ground level or above the established airport elevation (whichever is greater) within three nautical miles of the established ARP of the airports listed in Section 16.Appendix A.  It increases in height at a proportion of 100 feet for each additional nautical mile of distance up to six nautical miles from the airport reference point up to a maximum height of 500 feet (see Section 16.Illustration C).

b)         Beyond the six nautical mile criterion in subsection (a) of this Section, an object would be an obstruction to air navigation if at a height greater than 500 feet above ground level at its site (see Section 16.Illustration D).