CV88: I was happy to see that Douglas report--- It seems I have the year wrong in my post---DC-8 Supersonic 1961
--- still the first!
ChristaansJ: actually I believe the Boeing figures were TMN not IMN---so position error and compressibility errors were accounted for were accounted for
--- the account I read of the test was from Davies' "Handling the Big Jets", I have to take a look