I once crossed 11000' over the top of a line just west of Chicago. I was young and dumb, and a senior guy was in the left seat. We started at FL370. Big bump, and we started going up. Throttles closed, A/P off, nose down as far as we dared, MMO approaching, boards up, up and away we went.
Topped out at FL440 in a G2, idle power, boards up (Ceiling FL450).
Chicago center had no one above us (it was ISA+10) as I remember (Thank you Lord). They shut anyone from following us after that. The guy in front of us busted his service ceiling (an MD80 that started at FL330).
We drifted back down to FL 370 with the boards up, throttles closed, and tried to stabilize the cabin altitude.
After that, I had a personal rule about crossing rapidly building lines.
Don't.
The 47000' rumor for an A330? As clean as that airframe is, above SVC ceiling, at night, in or above wx, no horizon (visual or artificial), possibly no A/S display?
No way you'd walk away from that one. But then we already knew that.