Any person desiring to erect any structure, or increase the height of any structure, or permit the increases in height of any object of natural growth, or otherwise use his property in any manner in conflict with airport zoning regulations adopted under sections 4563.01 to 4563.21, inclusive, of the Revised Code, may apply to the airport zoning board of appeals for a variance from the zoning regulations in question. Such variance shall be allowed where a literal application or enforcement of the regulations would result in unnecessary hardship and the relief granted would not be contrary to the public interest or create conditions dangerous to the safety of aircraft using the airport, but would do substantial justice and would not be in conflict with factors set down for consideration in sections 4563.07 and 4563.08 of the Revised Code. The board of appeals may subject any variance to any reasonable conditions that they deem necessary.