Originally Posted by
Softpayman
High 20's is a bit of an exaggeration. Low 30's yes. FL320/330 to start. Maybe up to 370 at the end of a transcon.
I used to fly a lot of Hawaii. Last year, I heard twice (I think it was AA and VA) putting in Flight Level requests headed eastbound.
Both times, they asked for something in the high 20s. When told "Unavailable, how about 310?", they said "No, we're too heavy."
That and my prior experience in the 320 made me think a heavier version with the same wing might get a small window between Mach buffet and low-speed buffet.