Bridgeport and Lee Vining Airport Issues / Opportunities / Constraints
The following briefly summarizes the major issues, opportunities and constraints concerning land use and airport operations in the Lee Vining and Bridgeport airport planning areas.
1. Airport operations inherently present certain risks to the general welfare of the public and residents within the airport vicinity, particularly within the area called the airport Safety Zone. The Safety Zone consists of:
a. The primary surface, runway and clear zones (see Figure 1: Airport Clear Zone);
b. The area underlying the runway approach and transitional surfaces (see Figure 2: Civil Airport Imaginary Surfaces); and
c. The area within the primary traffic pattern (see Figures 3 & 4: Primary Traffic Patterns).
2. Since aircraft align with the approach/departure surface, transitional surface and clear zone when landing or taking off on runways, these areas carry the highest volume of air traffic. Aircraft change power settings to take off or land in this area, so they have a tendency to have more problems within these zones. The convergence of aircraft landing and taking off within these narrow areas also intensifies the noise levels in these zones.
3. The clear zone, which is located immediately at the end of the runway, is particularly subject to these safety and noise factors. The limits of the clear zone are shown schematically on Figure 1. The clear zone is the most critical zone in which aircraft operations might affect the safety of people and property in the airport environs.
4. The impact of aircraft noise associated with airport operations is an obvious factor in determining land use compatibility within the planning area. A noise impact analysis has been prepared for the Bryant Field Airport Master Plan, and noise readings have been taken for the Lee Vining Airport. Noise activity directly related to Bryant Field and Lee Vining airports does not extend much beyond the area of the airport property (see Figures 5 & 6). Consistent with the Mammoth/June Lake Airport Land Use Plan, this plan assumes that 55 dB CNEL is the maximum acceptable noise exposure level for residential uses, without soundproofing.
At Bryant Field Airport, the 55 dB CNEL contour projects partially into the residential area to the east of the airport. The airport noise impact to this area is infrequent and intermittent, and therefore not significant; this same area experiences greater and more frequent noise impacts from the adjacent highway traffic on SR 182. A drastic increase in airport activity could cause the impact to become significant in the future. No residential development or other sensitive noise receptors presently exist or are planned adjacent to the Lee Vining Airport.
5. Due to the inherent risks presented by airport activities, some land uses need to be restricted in certain airport zones. Neither Bryant Field nor the Lee Vining airport is situated in a manner that significantly conflicts with existing land use. Several structures are located within the clear zone of Bryant Field, and a number of residential structures are located in the Bryant Field approach surface. The County has actively pursued acquisition of buildings/property in the clear zone.
6. The prevalence of USFS and City of Los Angeles land ownership in the vicinity of the Lee Vining Airport limits potential future land use conflicts in the Lee Vining Airport planning area.
7. The location of Bryant Field within an area surrounded by agricultural lands, the Bridgeport Reservoir and wetlands limit the development potential and associated conflicts with airport operations. With the exception of several existing structures, the developed portions of Bridgeport are not within the airport's clear zone, although a number of structures are located at the end of the approach/departure surface.
FIGURE 01: AIRPORT CLEAR ZONE AND IMAGINARY SURFACES
