All safety has to be affordable, Sunny. That's why the response to the Germanwings tragedy wasn't a requirement for a third pilot with duty time in every cockpit to cover when the PIC or copilot go to the toilet, or an AD requiring that cockpit doors be moved backwards so that the toilet is secure to the crew.
An easily foreseeable risk - another 150 or so dead people - yet the obvious mitigators of those risks have not been implemented. The reason is simple and stark: It's not a cost that's justified by the risk. In short, it's not "affordable".
Those who feed off the mystique of aviation need to realise that the only way to achieve perfect aviation safety is to ban it. At that point you're going to have to find some other fear to feed off.
Last edited by Lead Balloon; 13th Mar 2016 at 11:30.