Just to see if I understood it correctly, and to give an image to some thoughts of previous posters.
It doesn't stop an error from being input, but given the RWY distance punched at the FMGC/MCDU and all the calcs for the V speeds (temps, wx, weights etc),
you just need 2 more parameters:
- Speed trend vector
- a way of measuring ground distance elapsed(GPS derived or wheel sensor)
Then its easy to determine if you'll be able to reach V1 inside min safe stopping distance, or at least if you'll get airborne at the very end of the RWY without taking the antenas with you. You just have to keep it above the green line.
Go easy on the flack!
GD&L