To ask the Secretary of State for Transport if he will introduce the Australian N/70 system for measuring noise disturbance around Heathrow airport.
There are no plans to introduce the Australian N70 noise index at Heathrow. Aircraft noise exposure around Heathrow is quantified using noise contours based on the 16-hour Leg noise index. This index is based on significant scientific research correlating the Leq index with noise disturbance responses. No such correlation currently exists relating N70 contours with disturbance.