> Also note that not all (if not most) aircraft are not brand new and so would need all to be retrofitted and re-rerated w/ any new system and every single pilot retrained

Ah yes, I forgot, we never introduce new aircraft technology because it's too hard. Too bad we don't, it would be great to fit aircraft, with, say, anti-collision transponders and advanced ground proximity systems. Oh well, my mistake for even bringing it up.