GPS on the black boxes is good - but I think they have something similar already. I know they can "ping" a plane and see where it is. You can also consider more/longer training for pilots, flight attendants, mechanics, and anyone who works on the plane. Might want to mention TSA, since they control (to some extent) who gets on the plane, as well. The way the planes are constructed and what they are made from also matters, along with the age they are allowed to get to before they are retired.