"I did see a scholarly report once that claimed that most the noise from a modern jet is actually from the interaction with the air. Similarly most traffic noise, on a modern car, is from tyre against road. Sorry, don't have source to hand."

As an aircraft engine works by the interaction of hot gas and the air, might it not be expected that that is what causes the noise?

On a more serious point, I have an old school friend who has been active in the campaign against the third runway and I will ask what information he can throw on the matter. On which point, it is worth saying that if there is a strong Heathrow campaign in West London, people in East London need to make their voices heard, or the problem will just be exported to other parts of the region.