Originally Posted by
etudiant
Unless the postulated newer higher speed designs can operate at a different altitude, say 45,000-50,000ft, I'd think they would be quite disruptive to the regular traffic flow.
When RAE Farnborough got its first Buccaneer S2 in 1975, it did a lot of airways flights presumably for the pilots to familiarise themselves with VOR flying.
London Control complained they didn't 'like' it because it cruised at similar levels to most airliners (between about 270 and 330) but at a filed TAS of 550kts so it kept overtaking other traffic at the same level!