JT
I was expecting the performance heavyweights to post in this thread.
When V1 = VR, in what cases it can be ASD limited ?
We can say that in this case, V1 is "maximum", which can be regarded as maximum ASD, minimum TOD V1. If ASDA is not infinite, at least it is enough,.
I always thought that choosing "maximum V1" is done so that we have more chances to stop and stay on the ground rather than taking off.
In the 320 I feel like doing something worthless when I calculate V1 in a 3500 m runway from which 747s and 380s are taking off. All I want to know is VR and V2. Such one day in a wet 4000 m runway we used FCOM 2 tables to substract knots to dry V1, VR and V2. I called out V1, we waited till 10 knots later and called "rotate". I think we had still 2000 m remaining...In some cases V1 is simply ridiculous. In others it has a meaning.
I look at V1 as a decision speed, in the sense that I don't intend to assess the situation too much if something happens during take off. Before V1, stop, at or above V1, go. No thinking. The thinking is made before the event. Obviously I will stop in case of a catastrophic failure. I don't know what happened to that 74 nor how a captain knows that a wing is no fire. An engine fire is no reason for rejecting after rotation, unless you are certain that there is runway enough, and that must be difficult with a 747...