(A) The owner of any nonconforming structure or tree is hereby required to permit the installation, operation and maintenance thereon of the markers and lights as shall be deemed necessary the Zoning Administrator to indicate the operators of aircraft in the vicinity of the airport the presence of the airport hazards. The markers and lights shall be installed, operated and maintained at the expense of the city.
(B) Any permit or variance granted by the Zoning Administrator or Board of Adjustment as the case may be, may, if the action is deemed advisable to effectuate the purpose of this chapter and be reasonable in the circumstances, so condition the permit or variance as to require the owner of the structure or tree in question at his or her own expense, to install, operate and maintain thereon the markers and lights as may be necessary to indicate to pilots the presence of an airport hazard.
(`86 Code, § 12.10)