I've just come across this thread after posting a comment on another thread about plane noise.
I have lived in SW11 for 13 years and, like the person who wrote the initial post, noticed a sudden & definite increase in plane noise in approximately September 2018. This level of noise, and frequency, has continued regularly ever since and is having a major effect on our quality of life.
I would appreciate any explanation as Heathrow denies that anything has changed. This does not make sense.
Note: Wandsworth Council has now deleted the page which was linked to in the original post, where people were able to leave comments about Heathrow noise. It seems they have no interest in this issue anymore, if they ever did.