Excellent technical talk by Jim Payne, the Chief Pilot, about the Perlan glider.
At FL900, Vso is 40 kts, Vne is 54 kts!
“Watch your attitude, Bloggs!”
EAA?s The Green Dot ? Jim Payne ? EAA Blog
Vso and Vne coincide at FL960. There is an interesting discussion about why 100,000’ was not a feasible design goal.