Quite revealing that everyone opposed to an FO calling "stop" bases their position on the FO lacking the required training.
Simple fix to that problem is to give the FO more training!! Ahhhh but that costs money!!!
Statistics are great. However, remember that FAA studies using "FO's" would in order to represent the actual population have to include a number of non-type rated pilots who under FAA rules were (quite legally) operating as FO.
As I said at the start, with a well trained crew, the SOP can be that either pilot can call stop but the PIC can decide to override that call. Basically, PIC can call STOP or GO while FO can only call STOP and even then the issues where a STOP can be called by the FO are very limited.
The Take-off Training Safety Aid makes much of the various rejected take-off's that ran off the end - most initiated above V1.
The big issue to me is the time available close to V1.
From the FAA - "virtually any take-off can be 'successfully' rejected if the reject is initiated early enough and is conducted properly.
From Airbus - When the aircraft is near V1 the aircraft rolls at about 60 to 80m per second and accelerates at 4 to 8 knots per second.
Therefore, a 1 second delay near V1 puts the aircraft an average of
both 70m further down the runway and 6 knots faster.
Having the FO call STOP does not comitt the aircraft to stopping any more than having them call FIRE. However, provided the training and testing is comprehensive and the briefings with regard to when the call is made are clearly understood then they should be able to make the call clearly and correctly.
In this case there is only 1 word that the PIC is listening for - "STOP". Sounds the same regardless of nationality, language ability or accent.
Ask Airbus or Boeing how much extra time they have allocated for their recomendation so that the 2 seconds or more the PIC is going to take to initiate a stop based on a call from the FO 2 seconds (12 knots) prior to V1.
Ask them to certify that the aircraft will safely get airborne from an engine failure more than 12 knots below the wet V1 on a limiting runway and I can bet we all know what the answer will be!!! Ask them at wet V1 - 12Kt smoke in the cockpit is it safer to stop or go?
How will your "nervous Nelly" FO describe the whisps of smoke they see round their right leg Pugilistic Animus?
I get the impression that with some operators saving training costs has come ahead of addressing the time critical area of the take-off just prior to V1.
From the above, I take it that no one includes the PIC heart attack at 95Kt in their training scenarios?
Where is the incapacitation cover if the SIC can not stop the aircraft properly with an appropriate failure??????? What are SIC's trained to do if they shout a failure and get no response?????? Where is the CRM?