[HISTORY: Adopted by the Annual Town Meeting of the Town of Nantucket 4-15-2003 by Art. 72, approved 7-22-2003. Amendments noted where applicable.]
As used in this chapter, unless the context otherwise requires:
AIRPORT
The Nantucket Memorial Airport.
AIRPORT APPROACH ZONE
Any airspace above the areas defined and shown on a map entitled “Map of Approach Zones, Nantucket Memorial Airport, Nantucket, Massachusetts,” dated February 11, 2003, and which is made a part hereof, as provided in MGL c. 90, § 40A.
AIRPORT HAZARD
Any structure or tree that extends into any Airport Approach Zone.
STRUCTURE
Any object or structure installed by persons, including any object regulated or licensed under any other provision of law.
TREE
A tree or other object of natural growth.
It is hereby declared that the existence of any airport hazard endangers the lives and property of the users of the municipal Airport and the occupants of the land in its vicinity, and effects a reduction of the area available for the landing, taking off and maneuvering of aircraft, thus tending to impair the utility of the Airport and the public investment therein. Accordingly, it is necessary in the interest of public health, safety and general welfare that the creation, establishment or maintenance of airport hazards be prevented by exercise of police power, without compensation to any person, except as herein specifically provided.
The Airport Commission is hereby designated as the administrative agency charged with the duty of administering and enforcing this chapter.
Except as otherwise provided in this chapter, no structure may be erected nor altered nor any tree permitted to grow or be maintained to a height which would exceed the elevation of the end of the runway by a vertical distance hereby established for each of the following areas, as shown and indicated on the Map of the Approach Zones:
A. 
Area A. One-twentieth of the shortest horizontal distance from the structure or tree (or any part thereof) to a line 200 feet outward from and parallel to the end of the runway within the approach zone in which the structure or tree is located.
B. 
Area B. One-fiftieth of the shortest horizontal distance from the structure or tree (or any part thereof) to a line 200 feet outward from and parallel to the end of the runway within the approach zone in which the structure or tree is located.
C. 
Area C. One-fortieth of the shortest horizontal distance from the structure or tree (or any part thereof) to the outer end of Area B, such vertical height to be exclusive of and in addition to the vertical height limit permitted at the outer end of Area B, within the approach zone in which the structure or tree is located.
D. 
Area D. One thirty-fourth of the shortest horizontal distance from the structure or tree (or any part thereof) to a line 200 feet outward from and parallel to the end of the runway within the approach zone in which the structure or tree is located.
Except as otherwise provided in this chapter, no structure may be erected or altered or any tree permitted to grow or be maintained to a height which would exceed the elevation of the horizontal surface, the conical surface, or the transitional surface, as hereby established for each, as shown and indicated on the Map of the Approach Zones.
A. 
Horizontal surface. An elevation of 198 feet above mean sea level, except that if § 53-4 requires a lower elevation within Area A, Area B, Area C, or Area D, at the point in question, such lower elevation shall control.
B. 
Conical surface. An elevation rising uniformly at a rate of one foot every 20 feet from 198 feet above mean sea level from the inner edge of the conical surface (being also the outer edge of the horizontal surface) to 398 feet above mean sea level at the outer edge of the conical surface, except that if § 53-4 requires a lower elevation within Area A, B, C, or D, at the point in question, such lower elevation shall control.
C. 
Transitional surfaces. The elevation of the transitional surface shall be that of a set of planes sloping upward and outward from the edges of Areas A, B, C, and D to meet the horizontal and conical surfaces. Each plane shall rise one foot for every seven feet from the edge of Area A, B, C or D, whichever may be applicable, measured horizontally at right angles to the nearest runway centerline.
Any person desiring to erect or increase the height of any structure, or to permit the growth of any tree, in a manner not conforming to the Airport Approach Regulations as herein established, or to establish the right so to do, may apply to the Airport Commission for a variance from the regulations applicable to such person’s property. Such variance may be allowed where a literal application or enforcement of such regulation would result in practical difficulty or unnecessary hardship and the relief granted would not be contrary to public interest. Any permit or variance granted under this section shall be conditioned as to require the owner of the Structure or tree to permit the Airport Commission at its own expense to install, operate and maintain suitable obstruction markings or obstruction lights thereon.
Nothing in this chapter shall be construed as prohibiting the growth, erection or maintenance of a tree or structure to a height up to 20 feet above the surface of the land.