IOA CONSULTATION QUESTIONNAIRE FOR “METHODS FOR RATING AMPLITUDE MODULATION IN

This document is written to initiate the discussion and asks a number of specific questions but feedback is encouraged on all aspects of the document, whether positive or negative, and it is not necessary to limit the response to the questions in this document. [...] REF has carried out the exercise on the Askam data for both the original Den Brook AM condition and the RUK AM condition and shown that the former condition would be breached and the latter not breached at Askam.3 16. [...] Given that three of the members of the IoA AM NWG were involved with drafting and validating the Den Brook amended AM condition, we are surprised and concerned that this loophole in the definition of AM has been allowed to persist in the IoA document. [...] What is omitted is the crucial part of Condition 21 that states if the AM levels breach the original 3dB limit set by a planning inspector, the noise data is filtered via a Fourier transform to restrict the assessed noise data to blade passing frequency +/- 10%. [...] It is important that the Den Brook condition 21 scheme is correctly characterised in the IoA document because the increase in permitted AM depth was justified on the basis of the definition of AM which is the same as the IoA are proposing in this consultation.