Originally Posted by john_tullamarine
(b) the 20000 ft admonition is, if I recall......... and may be associated with undesirable roll rates ...
Years ago, wanting to find out where the similar restriction in the L-1011 came from, I took a few loose minutes in a sim session, and tried it out at FL 250.
N'eer truer word were spake. The normally docile and ladylike queen of the skies became a real handfull in the roll axis with yours truly setting up what can only be described as a series of impressive P.I.O manoevres. If the real aircraft behaves like the sim at those altitudes, the restrictions are there for very good reasons.
I gained a newfound respect for "odd" limitations.