Ssg,
After reading your posts throughout this thread, I see your name by a post and it only brings question marks. Put down the helium, man, and come back to earth.
If an aircraft is ten tonnes overweight, then the performance numbers for that aircraft aren't valid. Neither are the stopping parameters, distances, or even the brake energy potential. Taking off that overweight is a train wreck already in motion, whether the aircraft gets off the ground or not. It's an idiotic argument.
One might debate the merits of lighting the airplane on fire and then attempting to takeoff, departing with spoilers deployed, flat tires, or any other wild scenario.
Yes, one needs to be aware of one's stopping distance, but when one throws the numbers so far out as to make them entirely meaningless (ten tonnes over may not fly, but may not be stoppable, either...the flight is doomed regardless of what they do), then all bets are off.
This is entirely meaningless in the face of the present topic; pilot incapacitation in a multi-pilot crew. You've come up with illuminating, but entirely irrelevant examples of departing the wrong runway using a crew that isn't incapacitated, and departing grossly overweight with a crew that isn't incapacitated to help address the topic of rejecting a takeoff for a crewmember incapacitation? Exactly why?
The Comair example used an airplane which departed an unlighted runway which was too short, for which they were not cleared, and which wasn't even parallel with or aligned with the cleared runway; numerous mistakes made before ever pushing up the thrust levers. Same for the Cotonou mishap.
Your assertion here is that the crew should be keeping track of their progress down the runway and make a decision to reject based on the percentage of the runway flow. You've even introduced a Part 135 guideline to emphasize the point. No doubt events such as the infamous Air Florida trip into the Potomac River wouldn't have occured if the crew had been better aware of their progress on the runway and acted accordingly. Are you suggesting that at the moment of pilot incapacitation the monitoring pilot evaluate the remaining runway and make a decision based on his evaluation on the fly to either continue or reject?
This is established before departure. Crews know and understand that high speed rejected takeoffs have a very high potential to end badly. During a high speed rejected takeoff, much, if not most of the runway is behind. Continuing the takeoff, especially when the aircraft is functioning well and has the performance and capability to do so, makes a lot of sense...particularly when returning to land will magically put the entire runway in front of the airplane for stopping distance.
Throw out all sorts of wild and irrelevant scenarios if you like...these only serve to cloud the topic under discussion, which is rejecting a takeoff for an incapacitated pilot. Departing unlighted, closed, wrong runways in the dark, taking off grossly overweight, or any other irrelevant example doesn't help address the question at hand, and it's really starting to make you sound rather foolish. Let's try to keep on track.
There seems to be a total lack of understanding on how much runway a plane should use up getting to thier V speeds.
Our performance calculation system, the ONLY data we are authorized to use, does not provide distance information to V1, and doesn't even tell us what the distance is to stop from V1 or go...what it does do is tell us what distance will be remaining if we elect to reject. Even if the data we have popped out a number that told us at V1 we had 63.3% of the runway behind, there just isn't any data alongside the runway (say, a big square black sign with a white border that says "63.3%) on it to use...nor would we be authorized to use it, nor does Boeing provide it, nor does Part 121 authorize it, nor does...anybody use it.
We see red lights during a normal takeoff, regularly. Aversion to high-speed rejected takeoff? You bet. You should educate yourself a little on the subject, but suffice it to say, a high speed reject is a risky endevor. As the size of the aircraft increases and along with it the mass, reduced stopping power, and rapidly rising brake temperatures and reduced stopping ability, control ability, etc...high speed rejects are far more risky than simply going airborne and coming back to put the entire runway ahead of you...with the situation under control and planned in advance.