The Bell 47 is an irregular regular along the Thames over the last 2-3 years. Always nice to see and hear, somehow endearingly friendly. Yes 'Radar' controlled, but also 'Klinger' control perhaps as the replacement on the series.
The CAVOK An-12 was impressively noisy today, seemed to have been in Nigeria a day or so ago and now likely headed to the US etc. They certainly get around!