St Athan - Sound Barrier
I believe that the term 'Sound Barrier' was first coined by the media? It was certainly used to excess in the newspapers when John Derry became the first pilot in Britain to exceed Mach 1.0 in a DH 108 on 6 September 1948.
Beagle: I presume that you are referring to the Chivenor Air Day in September 1954 when a certain Capt Rosencranz USAF was alleged to have exceeded the speed of sound during a 'fast run' in one of the unit's Sabres?