"7.9 However, Article 4.4 of Directive 2002/30/EC and Regulation 5(3) of SI No. 1742 preclude the use of any system of noise classification other than that based on 'ICAO noise certification data'. It follows that, although the UK (and other Member States) may choose how to use the noise certification data when imposing operating restrictions, it has no discretion to substitute measurements of operational noise as an alternative to the noise certification data. That would have the effect of decoupling the classification of the aircraft concerned from their noise certification data. We are, therefore, not consulting on this issue."
"Because he has wrongly directed himself as bound to treat the ICAO figures as accurate, the defendant has expressly failed to consult on the issue of how noisy these aircraft actually are and therefore on the consequences to be drawn from their actual noise levels at stage 2."
"1. The Defendant [that is to say the Secretary of State] is entitled to have regard to the operational noise of aircraft (and not merely to ICAO Certification Data) in formulating operating restrictions."