Any permit or variance granted under §§ 154.14 or 154.27 may, if such action is deemed advisable to effectuate the purposes of this chapter and reasonable in the circumstances, be so conditioned as to require the owner of the structure or tree in question to permit the present owner or lessor at his own expense, to install, operate, and maintain thereon such markers and lights as may be necessary to indicate to flyers the presence of an airport hazard. ('71 Code, Appendix A, § 9) (Ord. passed 6-4-57)