Nah, no 747 could get close to M 1.0 in level flight - The one that did the M 0.991 run had about 10° nose down, I think, to get up to that speed.
In one of the previous companies I worked for, one night out in the middle of no-where, the 747 (I wasn't on board) got hit with a big standing wave, and in a few seconds the mach number went from 0.85 up to 0.96 on the ASI!!
(Mmo 0.92) The Captain kept his cool and just pulled the power back, and let the speed bleed off over a minute or so. An airframe inspection revealed no damage at all.
I think about the fastest you could go in, say, a Roller powered -200 would be about M 0.9 or so, depending on the weight, temp, and altitude.
Here's a pic of one of the 747-100 (PW 7A powered) I flew that got caught in a small standing wave - we
were doing 0.84 a few seconds before that ...
Didn't feel a thing ...
[This message has been edited by 18Wheeler (edited 16 January 2001).]