Sispanys ria,
You stated;
"Any basic ppl student learns that on engine failure during final the best way is to go below the glide in order to keep speed and store kinetic energy since it the only way to control an aircraft and to flare with a low speed/fpm impact.
In the BA case there is obviously a very innovative way of managing dead stick landings since the "strategy" was to "burn" all of the available kinetic energy. As a result, with no more kinetic energy to control the path, the aircraft was controlled by its potential energy which threw it to the ground and resulted in substantial damages.
Can anybody elaborate on the advantages on keeping the AP fly the glide on a dead stick approach (which is opposite to the fundamentals taught in any correct flight school) ?"
Mate, for someone with an almighty "more than 3000TT" and 2500hrs Turbo prop PIC, don't you think it's a bit rich to start judging a BA 777 crew so harshly?
I am sure that they too can cast their minds back to how to fly an engine failure in a lightie and could discuss aerodynamics with you until the cows come home. Why not try and learn something rather than judge those more experienced than yourself? That way when you are in the left seat of a heavy you will be better prepared to handle situations as they arise.