Home › CFR › Title 14 › Part 17014 CFR Part 170 — Establishment and Discontinuance Criteria for Air Traffic Control Services and Navigational FacilitiesSubpart A — General§ 170.1— Scope.§ 170.3— Definitions.Subpart B — Airport Traffic Control Towers§ 170.11— Scope.§ 170.13— Airport Traffic Control Tower (ATCT) establishment criteria.§ 170.15— ATCT discontinuance criteria.