It is crystal clear to me now.
But I see that even academic books such as oxford aviation ATPL books, are wrong about Va...this is a BIG misconception that leads more and more ATPL pilots to learn Va in the wrong way.
For example (Principles Of Flight, Oxford aviation, 2008)
DESIGN MANOEUVRING SPEED, VA
The highest speed at which sudden, full elevator deflection (nose up) can be made without exceeding the design limit load factor.
Then it explains where it is on a V-n diagram, and then states:
For example an aircraft with a 1g stalling speed of 60kt and limit load factor of 2.5 would have a VA of:
60 √ 2.5 = 95 kt
This is, Vo that is explained by Oxford, not Va.
Anyway, same approach is taken by Bristol Groundschool, Jeppesen and many more manuals, even engineering manuals.
This is a BIG misconception!!!