If there is to be no third runway at our principal airport, he believes a lot can be done with a relaxation of the curfew rules. At present Heathrow is closed between 11pm and 5am. However, the new generation of jet aircraft such as A380s and Boeing 777s are far quieter than the last — a fully loaded 777-300 is 40 per cent quieter than existing 747-400s – and if you were to add an extra hour of take-off and landings on either side of the day and restrict that to low-noise aircraft you would be adding considerable capacity to Heathrow. It certainly would take some of the pressure off.