An airport, presently known as Perkiomen Valley Airport, has existed in Skippack Township since 1939. The airport is surrounded by residentially used or zoned properties. The purpose of this article is to regulate the obstructions that have the potential for endangering the lives and property of users of the Airport, of property and of occupants in its vicinity, while, at the same time respecting the rights of owners of property located in the vicinity of the airport. The Board hereby recognizes that:

Accordingly, it is declared that:

Utility Runway Visual Approach Zone. The inner edge of this approach zone coincides with the width of the primary surface and is 250 feet wide. The approach zone expands outward uniformly to a width of 1,250 feet in a horizontal distance of 5,000 feet from the primary surface. Its center line is the continuation of the runway.

Utility Runway Nonprecision Instrument Approach Zone. The inner edge of this approach zone coincides with the width of the primary surface and is 500 feet wide. The approach zone expands outward uniformly to a width of 2,000 feet at a horizontal distance of 5,000 feet from the primary surface. Its center line is the continuation of the center line of the runway.

Precision Instrument Runway Approach Zone. The inner edge of this approach zone coincides with the width of the primary surface and is 1,000 feet wide. The approach zone expands outward uniformly to a width of 16,000 feet at a horizontal distance of 50,000 feet from the primary surface. Its center line is the continuation of the center line of the runway.

Transitional Zone. The Transitional Zones are the areas beneath the transitional surfaces adjacent to each runway and approach surface.

Horizontal Zone. The Horizontal Zone is established beneath the horizontal surface, 150 feet above the established airport elevation, the perimeter of which is constructed by swinging arcs from the center of each end of the primary surface of each runway and connecting the adjacent arcs by drawing lines tangent to those arcs. The Horizontal Zone does not include the approach and transitional zones, as shown on the Airport Zoning Overlay Map.[2]

Conical Zone. The Conical Zone commences at the periphery of the Horizontal Zone and extends outward therefrom a horizontal distance of 4,000 feet.

Utility Runway Visual Approach Zone: slopes 20 feet outward for each foot upward beginning at the end of and at the same elevation as the primary surface and extending to a horizontal distance of 5,000 feet along the extended runway center line.

Utility Runway Nonprecision Instrument Approach Zone: slopes 20 feet outward for each foot upward beginning at the end of and at the same elevation as the primary surface and extending to a horizontal distance of 5,000 feet along the extended runway center line.

Precision Instrument Runway Approach Zone: slopes 50 feet outward for each foot upward beginning at the end of and at the same elevation as the primary surface and extending to a horizontal distance of 10,000 feet along the extended runway center line; then slopes upward 40 feet horizontally for each foot vertically to an additional horizontal distance of 40,000 feet along the extended runway center line.

Transitional Zones: Slopes seven feet outward for each foot upward beginning at the sides of and at the same elevation as the primary surface and the approach surface, and extending to a height of 150 feet above the airport elevation, as noted on the Airport Overlay Zoning Map. In addition to the foregoing, there are established height limits sloping seven feet outward for each foot upward beginning at the sides of and at the same elevation as the approach surface, and extending to where they intersect the conical surface. Where the precision instrument runway approach zone projects beyond the Conical Zone, there are established height limits sloping seven feet outward for each foot upward beginning at the sides of and at the same elevation as the approach surface, and extending a horizontal distance of 5,000 feet measured at ninety-degree angles to the extended runway center line.

Horizontal Zone: established at 150 feet above the airport elevation.

Conical Zone: slopes 20 feet outward for each foot upward beginning at the periphery of the horizontal zone and at 150 feet above the airport elevation and extending to a height of 350 feet above the airport elevation.

Notwithstanding any other provisions of this article, no use may be made of land or water within any zone established by this article in such a manner as to create electrical interference with navigational signals or radio communication between the airport and aircraft, make it difficult for pilots to distinguish between airport lights and others, result in glare in the eyes of pilots using the airport, impair visibility in the vicinity of the airport, create bird strike hazards, or otherwise in any way endanger or interfere with the landing, takeoff, or maneuvering of aircraft intending to use the airport.

Recognizing that the regulations in this article could result in the laying of a dead hand upon all or a portion of properties adjacent to or nearby the airport, the use of any such property shall be regulated by the following Conditional Use provisions.

The regulations prescribed in this article shall not be construed to require the removal, lowering, or other change or alteration of any structure or tree not conforming to the regulations at the effective date of this article, or otherwise interfere with the continuance of a nonconforming use. Nothing contained herein shall require any change in the construction, alteration, or intended use of any structure, the construction or alteration of which was begun prior to the effective date of this article, and is diligently prosecuted.

Notwithstanding the preceding provision of this section, the owner of any existing nonconforming structure or tree is hereby required to permit the installation, operation, and maintenance thereon or nearby of such markers and lights which are necessary to indicate to the operators of aircraft in the vicinity of the airport the presence of such airport hazard. Such markers and lights shall be installed, operated, and maintained at the expense of the airport.

Any trees which presently exist or are hereafter lawfully planted on any property which is governed by this article may continue to exist, even if they become a hazard. However, if now-existing or hereafter-planted trees become a hazard, the airport may apply to the Township Zoning Officer for permission to temporarily enter upon the property on which such trees are located for the sole purpose of causing such tree or trees to be properly trimmed to a height which would not constitute a hazard, but the tree shall not be trimmed to a height below that height at which the tree stood at the time of passage of this article. The trimming shall only be conducted by an arborist who is acceptable to the Township and the property owner. Prior to entering on the property where such trees are located, the person performing the trimming operation shall deliver to the Township Zoning Officer proof of general liability insurance coverage in an amount reasonably required by the Township Zoning Officer. The property owner shall be bound by this provision.

The baseline for nonconforming uses and trees shall be established by a study performed by the Bureau of Aviation, which study shall be done within six months following the passage of this article.