is it true that the FE had a dial on his panel that allowed him to adjust the displayed Mach in the pax cabin on up to 2.0 for the passengers who paid for this....on days when ambient conditions prevented getting to Mach 2
I doubt most of the pax knew or cared what M2.0 was. The FL600 trip I had was an oddity as most of the time it used to flounder around at FL530-550 as it burned off fuel. I could have had at one time explained the tropodisaurian reason for this but I've forgotten and I can't remember why I've forgotten.