I live in South London and read this post yesterday. Later on I returned home, relaxing having a cup of tea, reading the news on the web and then suddenly heard what sounded like a turbo prop flying lower than normal straight over my flat.
Quickly grabbed the bino's and ran to the lounge window... was quite excited to watch what I thought was the discussed above plane, but then as I watched it fly north, over central London, it began turning East.
Then the penny dropped
LCY on Easterlies.
It was a normal arrival of (I think) a fokker.
Definately lower than normal though!
Tail between legs, went and boiled the kettle again!