If we simply took any individual actually carrying an explosive device and shot him or her on the spot at the airport and hung the body up for public viewing, we could probably get away with a less than 1% detection rate.
Alas, that would generate additional inefficiencies in the system that would make air travel about as inconvenient as it is now.
Check my earlier post where I advocate moving away from mind-numbingly uniform evaluations of place in line to actual evaluation of statistically correlatable physical charateristics to identify probable terrorists.
Were this a case of "logical" terrorists, the 1% might be deterred. But when talking about religious fanatics, the same logic doesn't apply.
I’m not familiar with the in-motion equipment you reference, but their existence wouldn’t surprise me. I find your paradym of quality control interesting, definitely worthy of more thought.