(a) Permits for Continuance of Nonconforming Uses.

(1) The owner of any structure or object of natural growth existing at the time of the adoption of airport zoning regulations under authority of this subchapter which does not conform to the regulations may be granted a permit authorizing continuance of the nonconforming use upon application made by him to the board, commission, or agency authorized to administer and enforce the regulations.

(2) If the application is not made within ninety (90) days of the effective date of the regulations in question, the board, commission, or agency may, by appropriate action, compel the owner of the nonconforming structure or object of natural growth to lower or remove the object to the extent necessary to conform to the regulations.

(b) Permits for Change and Repair of Nonconforming Uses. (1) (A) Before any existing nonconforming structure or object of natural growth for which a permit has been issued in accordance with subsection (a) of this section may be altered, repaired, rebuilt, allowed to grow higher, or replanted, a permit must be secured from the board, commission, or agency authorized to administer and enforce the regulations authorizing the change or repair.

(B)

(i) No permit shall be granted that would permit the structure or object of natural growth in question to be made higher or become a greater hazard to air navigation than it was when the permit for its continuance was granted under subsection (a) of this section.

(ii) Where the structure or object of natural growth has been more than fifty percent (50%) torn down or destroyed, whether voluntarily, by act of God, or otherwise, or has become more than fifty percent (50%) deteriorated or decayed, no permit shall be granted that would permit the structure or object of natural growth to exceed the applicable height limit prescribed by the zoning regulations; instead, in all cases of fifty percent (50%) destruction, deterioration, or decay, whether application is made for a permit for repair or not, the board or agency shall by appropriate action compel the owner of the nonconforming structure or object of natural growth to lower or remove the object to the extent necessary to conform to the height limit.

(2) Except as indicated, all applications for permits for change or repair of nonconforming uses shall be granted.

(c) Permits for All Uses. Where advisable to facilitate the enforcement of zoning regulations adopted pursuant to this subchapter, a system for the granting of permits for all uses and structures within the zoned area may be established.

(d) Variances.

(1) Any person desiring to erect any structure or increase the height of any structure or permit the growth of any object of natural growth, in excess of height limits prescribed under authority of this subchapter, must apply to the board, commission, or agency authorized to consider these applications for a variance from the zoning regulations in question.

(2) Variances shall be allowed upon a showing of practical difficulty or unnecessary hardship, together with a showing that the structure or object of natural growth in question will not constitute an undue hazard to aircraft operations at the airport.

(e) Obstruction Marking and Lighting. In granting any application for any permit or variance in accordance with this section, the board, commission, or agency authorized to do so may, if it deems the action advisable to effectuate the purposes of this subchapter, so condition the permit or variance as to require the owner of the structure or object of natural growth in question to install and maintain obstruction marking or lighting.

(f) Exhaustion of Remedies. No person desiring to continue a nonconforming use, to change or repair a nonconforming use, to take any action requiring a variance under subsection (d) of this section, or to take any other action covered by this section shall initiate any action in the courts unless and until he has exhausted the remedies provided by this section.