I refer to Clara Wong's response (South China Morning Post, August 27) on behalf of the Director-General of Civil Aviation to the letter from Tony Ostheimer (Post, August 15) on aircraft noise. Since the opening of the new airport four years ago, the northeast departing night flights, although easing Jardine's Lookout's problems, have caused considerable noise nuisance to the less-affluent residents overlooking the sea at Tung Wan and Kwun Yam Wan on Cheung Chau. I would be interested to know what steps are being taken to mitigate the excessive noise pollution created by helicopters using the pad between Tung Wan and Kwun Yam Wan beaches, both during the day and at night. I am quite sure that they are considerably in excess of the 56.4 to 73.3 decibels range (average 63 decibels) quoted for Jardine's Lookout. Perhaps the Director-General of Civil Aviation would be kind enough to provide comparative figures for the helipad and for night flights on Cheung Chau. MICHAEL GUILFORD Yau Yat Chuen
