Discussion

PROFESSOR LARGE I am not an expert in aircraft noise monitoring but this is a noise control technique undervalued except by the instrumentation manufacturers. It can be a valuable link in the noise control picture, particularly with the advent of new aircraft types and operational techniques.

Monitoring has been an acceptable technique for aircraft noise control since the mid 50s. There are a variety of systems used. In addition to those mentioned in my Paper there is an ISO recommended practice and one of the more interesting concepts is the dynamic preferential runway system now in operation at Kennedy. This is not really a monitoring system in the traditional sense but an operational procedure. It has produced fewer complaints even though community dissatisfaction with the airport has continued to grow. Work in the UK and in the USA shows that complaints can be directly related to annoyance so perhaps this practice could be incorporated into the current minimum noise route philosophy around Heathrow.