Noise levels were probably measured during tour flights which sadly are accounting for a lot of movements and are amongst the noisiest of types are the heliport. Sorry to have to say it. Those that fly helipad PC1 profiles gain height quicker. But there’ll always be complainers and moaners. Same everywhere. The majority don’t hear it or notice it. The streets are far noisier. Go figure. Anything about the heliport being part of London’s emergency action plan? Pretty sure it is.