Originally Posted by
johns7022
So out of 76000 RTOs, 2% initiated at above 120kts...well past V1...let's stick with those..
2% x 76000 Total RTOs = 1520 High Speed RTOs
How many accidents? 74 = Less then one percent...or .05 percent.
Well, in fact, 74 out of 1520 is just under FIVE PERCENT. 1 in 20. Do you think a 1 in 20 risk of an accident/incident is a good basis for decision making?
Even 1 in 2000 - your erroneous value - is an unacceptable risk given that the expected/target accident rate is 1 per million. Anything which will cause a perceptible adverse change to that 1 in a million rate is a bad thing.
I'm going to go back to the 'Russian Roulette' analogy:
If I have a confirmed empty revolver, checked by myself and a trusted friend, then I can play Russian Roulette 'safely'. There remains the risk that my friend is secretly a psychopath, but on the whole it's safe. That's rejection before v1. Unless something exceptional occurs, it should be safe.
If I have a revolver picked randomly and handed to me by a stranger, to place it to my temple and pull the trigger is foolhardy, unless I am coerced to do so. That's rejection above V1 when I don't know what my margins are. Maybe all the chambers are empty and I'll get away with it. But maybe not. (Coercion = 'plane will not fly' by the way)
Even if I 'know' there is only one bullet in the chamber - analagous to understanding some of the margins for RTO above V1 - it's still a significantly elevanted risk. The risk of not playing/not going flying has to be very high for me to take the chance.