Investigating the potential of using quota count as a design metric

Identifying easy-to-use and easy-to-communicate extensive design metrics for aircraft noise could be of substantial benefit to the aircraft design community. The current means of communication often revolves around the margin to the certification stringencies. These stringencies are hard to communicate and not directly related to external impact. A good design metric correlates well with the individual aircraft's effect on these broader measures. This paper proposes the use of quota count, which was devised as a means of limiting nighttime exposure to single equivalent events at London area airports. It is directly related to the actual energy emitted by an aircraft and the resulting timeaveraged values observed on the ground. It is straightforward to communicate and comprehend. It is based upon the certification noise values, and therefore straightforward for a design engineer to model. This paper answers the question: Does quota count relate well with cumulative measures, especially day-night noise level estimates of the area exposed to a given cumulative level? Given that quota count, and a simple cumulative quota count model, correlate highly with these measures, it is reasonable to suggest that quota count be used as a primary noise metric for new designs. Copyright © 2011 by Peter Hollingsworth and David Sulitzer.