A person desiring to erect or increase the height of a structure, or to permit the growth of any tree, or otherwise use the person’s property in violation of airport zoning regulations adopted under this chapter, may apply to the board of zoning appeals or joint board of appeals for a variance from the zoning regulations. The variances must be allowed where a literal application or enforcement of the regulations would result in practical difficulty or unnecessary hardship and the relief granted would not be contrary to the public interest, but would do substantial justice and be in accordance with the spirit of the regulations and this chapter. However, that any variance may be allowed subject to any reasonable conditions that the board of adjustment may consider necessary to effectuate the purposes of this chapter, including the reservation of the right of the governmental entity, at its own expense, to install, operate, and maintain on it markers and lights as may be necessary to indicate to operators of aircraft the presence of the airport hazard.