tommoutrie
I will be totally amazed if FSI teach anything but the AFM, otherwise they are on very very thin legal ice.
If they express a view otherwise I would get it in writing, with an indemnification. Warren would not be pleased.
Our experience is that if asked about non AFM approved manouevres they may express a personal view but will always return to the manufacturers AFM.
If the manufacturer allows their approved training org to do otherwise they will be codefendants, I dont think so.
You get exited in my organisation for using otherwise, and if a regulator (believe me in my part of the world they sometimes try) or an auditor tries to impose a personal prejudice outside the AFM as a condition of an approval then it's game on.
It usually starts with a polite but firm request from me for a formal personal indemnity from them and their organisation and always ends in a white flag. I have found, at least in my country, the amount of misinformation, lack of background knowledge, prejudice, legend, folkore, and Chief Pilotology astounding. I am fortunate to have been able to hand pick and mentor some outstanding people.
As I am sure you are aware the AFM is the FAA approved reduction of the performance derived from the manufacturers certification process and yes is based on OEI.
SillyPeoples has got it in one, its really all about the departure runway obstacle clearance basket (we use APG to provide RTOW which simplifies the preflight planning matter somewhat) within which we operate and ALL the calculations are based thereon for all combinations of where you may find yourself OEI at any time up to the end of the takeoff phase. The default position for the OEI calculation is V1.
Simply put, if you fly the speeds/AFM to 1500ft, or higher if the particular departure requires, you are gauranteed to have the required obstacled clearance whether one or both are going. Thats what V1 is about.
So, mess with that and you are now a manufacturers test pilot, in an uncertified aircraft and or only guessing where you might lay in the basket up to that point. "Well M'lud up to that point everything was going so well I thought I'd just wing it from there."
The subject under discussion seems to suggest that at some arbitrary time during the take of phase the pilot decides that everything is going just swimmingly so lets clean up and get going.
Sure the modern aircraft can perform all manner of interesting things but not what it can't.
What you can be sure of is that the manufacturer has squeezed the living daylights out of the performance calculations in your manual up to the certification limits available.
Why would they not do otherwise, they are trying to sell you an aircraft with the best possible performance, the FAA on the other hand are intent on keeping them honest.
I might be wrong but if they thought there was a better way it would be in the AFM.
Your theories may well be correct, but this little black duck wont be chancing his arm outside the AFM.
I have sat in court as an expert witness too many times and seen too many unintentional test pilots try to defend what they thought was a good idea at the time.
Anyway I have been wrong before.