When did the supersonic flights go public?
The Concorde was first flown supersonic in March 1969, but was
not used commercially until 1976. It was retired on 26 November
2003. A prototype of the Soviet Tupolev Tu-144 first flew on 31
December 1968, two months before the Concorde but did not break the
sound barrier until 5 June 1969. It's first commercial flight was
on 26 December 1975 and it was retired on 1 June 1978.