Originally Posted by
H Peacock
I do buy the cliff-edge argument, but for any normal runway (talking about big airports) why does a crew choose to...
It is not necessarily a crew decision. In some cases it may just be how the performance program spits out the data. Where I work we still use tabulated charts and have some limited visibility of the possible range of V1s. The V1 for our actual weight would be the lowest and the lower of Vr for actual weight or the V1 for the RTOW would be the highest available. Current procedure is to use the V1 for our actual weight, i.e. we are using the lowest available from the chart (we are "go minded"). In days past we would have used V1=Vr unless the RTOW V1 was lower (this equates to the highest V1 available - "stop minded").