Research carried out by the campaign group HACAN has revealed that Hounslow to be the most overflown borough in London. Richmond is in second place but the surprise is that that only three of the top 12 most boroughs are in West London with Waltham Forest being the third most overflown: http://hacan.org.uk/wp-content/uploads/2017/01/Most-overflown-boroughs-in-London-2016.pdf