Originally Posted by
adverse-bump
In flight testing, the v1 one has a 2 sec decision, and a 2 sec reaction built into it. so why would you take an extra 5 sec off? why not go with the flight manual?
Flight testing has no such thing, nor do the certification rules. And, as explained above, the flight manual is predicated on not just recognition but reaction having started at V1. Which means if AT V1 is when you start the "V1 process", you're already behind the aircraft.