Energy to be dissipated increases with the square of the speed don't forget. I would suggest that using the QRH Normal landing distance figures to extrapolate to Vref40+70 would not give you an accurate answer, and you have know knowledge in which direction the error is.
I would class that as "brave" behaviour personally.
I hope more people were braver then,if thinking and professional is your definition of being brave.
Again all flaps up is vref 40+55kts.
Any idea how Auto brakes work?
