Section 16.40  Surfaces and Height Limitations

a)         Height limitations are established through the use of airport imaginary surfaces as described in Sections 16.50 - 16.110.  The size of an imaginary surface relates to the category of aircraft expected to use the runway and the type of approach available or planned for that runway.  The slope and dimension of the approach surface applied to each end of a runway will be determined by the most precise approach, existing or planned, for that runway end.

b)         Airport imaginary surfaces are described in Sections 16.50 - 16.110.  Because these surfaces are the same as the approach surfaces in 14 CFR 77, effective October 1, 2002, an airport airspace drawing sheet of the currently approved ALP will serve as the visual representation of the imaginary surfaces for each airport (see Section 16.Appendix A).  These drawing sheets can be viewed at the Illinois Department of Transportation, Division of Aeronautics, Capital Airport, 1 Langhorne Bond Drive, Springfield, Illinois 62707.

c)         An area located in more than one of the surfaces described in Sections 16.50 - 16.120 is considered to be only in the surface with the most restrictive height limitation.

d)         Except as otherwise provided in this Part, no structure, equipment, vegetation, or material shall be erected, placed, altered, allowed to grow, or maintained at a height in excess of the limit established by the surfaces described in Sections 16.50 - 16.120.  Additionally, no use may be made of any area under a surface described in this Part that would constitute an airport hazard, as that term is defined in Section 16.130.

e)         The surfaces and height limitations established by this Part take into consideration future alterations of an airport, including runway relocation, extension, and new construction, as well as changes in runway approaches.  No person  may cause or allow a structure or vegetation to penetrate a surface associated with a planned change at an airport covered by this Part or penalties will be imposed.  Future changes planned by an airport may be found on the ALP which can be viewed by contacting the airport owner or the Division.