[Theodores]

Just to clarify, Concorde used afterburners for take-off and to get to supersonic speeds. When at speed it was able to supercruise without the afterburners.

What this meant in reality was that anyone in South West London (near to Heathrow but not necessarily just west of Heathrow) had this part of the day when the noise was terrible. You could be outside, sat down enjoying beers and all conversation would have to stop until this thing went overhead. Ear splitting was the word and there was no doubt the plane was Concorde.

Further down the road in the West Country the Concorde (there was only one!) would be able to be heard but it would not be announcing its presence and demanding that you stop everything that you were doing to look at it. At this stage it was high altitude but not on the supersonic super-cruise.

Then, over the Bristol Channel, Concorde would hit the afterburners good and proper to get up to full speed. People in Devon, Cornwall, South Wales and the south of Ireland would hear the boom albeit not at full intensity. It was still a 'boom' though.

If you look at the map and the size of the Bristol Channel then you can get an idea as to how big of an overland corridor you would need. It is huge, even for somewhere like Tibet.