Place was bloody quiet, hardly anyone out and about. I was walking up the hill towards Sanderstead, daydreaming and was quite startled by the sudden noise...
Yeah I'm aware of all the usual traffic - lots of daytime VFR keeping south of London CTR and north of the gliding activity at Kenley - but the last time I heard a light aircraft make quite that much racket over Purley, it was a Pitts doing aerobatics many years ago (illegally I should have thought, given how built up the place is!).