Originally Posted by qwertyuiop
Surely the answer is;
If you get a Config warning before V1 the aircraft CAN stop, but may not fly. Unless you brief otherwise you STOP.
How do you then define V1?
On a runway, there is a speed above which a plane that aborts will overrun. V1 should not be more than this.
There also is a speed under which the plane cannot fly with a very well defined single-point failure - namely 1 critical engine out, all other systems intact. The cause of being not allowed to fly might be inability to accelerate with the good engine/s to climb above the screen height by the end of runway, or clear obstacles further on flightpath. Or else the inability at slow airspeeds to keep the aircraft on runway against asymmetric thrust plus crosswind.
"Balanced field length" seems to be the length of runway where there are no margins of safety over and above the accelerate-stop distance. An aircraft could take off from a shorter runway, but is not allowed to, because there is a stretch of takeoff where one engine out would cause a certain crash.
Whereas if the craft takes off from a longer runway, there would be a stretch where both aborting and continuing would be safe... there would be leeway for pilot judgment what to prefer, no?
But BFL and V1 are defined by reference to a specific one-point failure - one engine inoperative. Configuration warning is a quite different error condition.
Examples to wrong configuration causing crashes include the Chinese Bae 146, as well as the first 747 to crash in Nairobi. In Nairobi, the slats did not deploy - the aircraft got airborne, but stalled past the end of runway and crashed with many deaths.
Did the pilots at Nairobi have (and miss) any chance to realize what happened and abort?