To police its physical property only and all waterways and to exercise police powers in respect thereto or in respect to the enforcement of any rule or regulation provided by the ordinances of the District and to employ and commission police officers and other qualified persons to enforce the same. The use of any such public airport or public airport facility of the District shall be subject to the reasonable regulation and control of the District and upon such reasonable terms and conditions as shall be established by its Board. A regulatory ordinance of the District adopted under any provisions of this Section may provide for a suspension or revocation of any rights or privileges within the control of the District for a violation of any such regulatory ordinance. Nothing in this Section or in other provisions of this Act shall be construed to authorize the Board to establish or enforce any regulation or rule in respect to aviation, or the operation or maintenance of any airport facility within its jurisdiction, which is in conflict with any federal or state law or regulation applicable to the same subject matter.