[beardyw]

I remember Concorde coming over in London, below supersonic, and even then it was very loud. Also, I may remember incorrectly, but Concorde never went into a holding pattern. All other flights were put on hold. Not sure if it was due to manoeuvrability or noise. I suppose you can do that with government help.

[MomoXenosaga]

Could also be lack of fuel. Concorde had barely enough range to fly to New York.