Scotbill
I think you may have got a thread crossed, I was referring to crossing West to East in a Gulfstream not a 757, but I take your point that an empty 757 could cross at the 40k ft + that I crossed at. However in my experience in commercial A/C it seems quite rare to be over the 40k ft. My last flight at that height was over 2 years ago on an EK 340 from Phuket back to DXB, where we had a good tailwind (80knots +) and were under a full Moon at 42k ft, quite spectacular views of the Anderman Sea as I re call.
Cheers
Mr Mac