Enhanced Preferential Runway Advisory System (ENPRAS)
Logan's Enhanced
Preferential Runway Advisory System (ENPRAS) is a computer program designed to
aid FAA controllers in selecting runways which will reduce Logan's noise impacts
whenever weather, demand, and other conditions permit. Since the recommendations
drive long- and short-term runway use, ENPRAS has a major impact on Logan
operations and their associated environmental impacts. The figure on the
right shows the ENPRAS computer installed in the TRACON at Logan.
The ENPRAS goals are the criteria used for runway selection and were established by a committee composed of representatives from the Massachusetts Port Authority, the Federal Aviation Administration, airlines operating at Logan, and twelve neighboring communities. The committee concluded that the ENPRAS goals should provide an equitable distribution of aircraft noise over the long-term (i.e. annually), as well as short-term relief from excessive operations over certain neighborhoods. The long-term goals were designed to reduce the total noise impacts of Logan operations on the population in nearby communities and to maximize the number of flights over water. The short-term goals were designed to limit the number of hours of jet overflights to which an individual community or area would be exposed within a specified time period.
The current version of ENPRAS is a forward-looking system designed to assist the FAA in planning operations throughout a shift. It operates 24 hours per day, providing a choice of recommended eight-hour configuration plans to the FAA operator, who can modify the plan as needed. Information on traffic demand, current weather, weather forecasts, runway closures, and runway conditions are provided automatically, and this information is considered along with the long- and short-term goals, controller workload, and configuration capacity to determine the plan recommendations. Performance relative to the goals has steadily improved over time, and FTA continually works with Massport and the FAA to add features and improve the system.
