HERBERT R. O'CONOR, GOVERNOR. 55

of land or structures or to make substantial changes therein
or thereon or substantial repairs thereto. In any event, before
any non-conforming structure or tree may be reconstructed,
replaced, substantially altered or repaired, rebuilt, allowed to
grow higher, or replanted, a permit must be secured from the
administrative agency authorized to administer and enforce
the zoning regulations, authorizing such replacement, change
or repair before any work is started, and no such permit shall
be granted that would allow the structure or tree in question
to be made or become higher or become a greater hazard to air
navigation than it was when the applicable zoning regulation
was adopted. All applications for permits for replacement,
change or repair of non-conforming uses, structures or trees
shall be granted as a matter of right except in those cases
herein specifically provided for.

(2) Variances. The legislative body of any political sub-
division may authorize and empower the Board of Appeals,
as provided in Section 62 (5) of this sub-title to grant vari-
ances from the zoning regulations adopted under this sub-title
in cases of practical difficulty or unnecessary hardship, subject
to such rules, regulations, restrictions, guides and standards,
as may be established by appropriate action of such legislative
body. Any person desiring to erect any structure, or increase
the height of any structure, or permit the growth of any tree,
or otherwise use his property, in violation of airport zoning
regulations adopted under this sub-title may make application
for a variance from the zoning regulations in question.

(3) Obstruction Marking and Lighting. In granting any
permit that does not have to be issued as a matter of right
under the provisions of this Section 61, or in granting a vari-
ance under the provisions of this Section 61, the said adminis-
trative agency or Board of Appeals, as the case may be, may,
if it deems such action advisable to effectuate the purposes of
this sub-title and reasonable in the circumstances, so condition
such permit or variance as to require the owner of the struc-
ture or tree in question to permit the political subdivision, at
its own expense, to install, operate and maintain suitable
obstruction markers and obstruction lights thereon.

62. Procedure.

(1) Adoption of Zoning Regulations. The legislative body
of the political subdivision, or the joint board provided
for in Section 60 (3) of this sub-title, shall provide for the
manner in which the boundaries of airport zoning districts
and airport zoning regulations and restrictions shall be deter-
mined, established, adopted and enforced, and from time to