PJ2 reminds us of the way the airframes of other a/c queuing for take-off would resonate as Concorde departed. Whether it was the responsibility of SNECMA or Rolls Royce (or even Bristol Siddeley?
), the reheat was certain to set off a random sprinkling of car alarms on the airfield, which used to make my day when lucky enough to be returning to the car park around midday at LHR.
Even without reheat, however, the engine had a distinctly military sound - quite unlike other civil turbojets I can remember. The sound of it in the descent at about 4000ft over my house at 5 pm daily was unmistakeable. On the approach, if you weren't expecting it, it could be quite unnerving. One night in the late 1970s, during a long car journey, I stopped for a call of nature at a well-known public house near Hatton Cross (about a mile from touchdown on LHR 27L). It was pitch dark, and I decided that the hedge at the side of the car park would be a suitable venue. Never having heard Concorde on the approach before, I became increasingly nervous as the sound, initially unidentified, got progressively louder. And then the landing lights were switched on...