PitR
As I understand it the 16 hour 63dB noise level does exactly what you suggest. It takes into account the individual noise of each movement over the period (depending on expected traffic mix presumably) and by some mathematical calculation produces the dB level that those movements at those particular noise levels represent over a 16 hour period. This is then factored in relation to the frequency of the noise events as that obviously has a considerably bearing on the overall annoyance/disturbance levels, so gaps between movements DO need to be taken into account.
I'm sure a little Googling will produce the formulae used and explain how it's all done, although I doubt that it makes for light reading.
I believe this same formula is applied to all UK airports so it isn't a case of SEN being an exception to the Government-imposed rule. Whether residents around all UK airports are therefore being "conned" I couldn't say.
Last edited by Expressflight; 29th Sep 2012 at 12:21.
Reason: additional text added