Don't worry about terrorism next time you take a flight. There is a very small risk, as an airline passenger, that you will die violently before you land, but it has nothing to do with terrorists. It is entirely down to the chance of an accident.
Consider this, if you don't believe it. The year 2001, which saw four entire airliners destroyed with total loss of life on 9/11, was not in fact a particularly dangerous year to go flying. More airline passengers died in the year 2000; nearly as many died in 2002. Twice as many were killed flying in 1972, despite the fact that many fewer people flew back then, because airliners were far less safe.
Terrorism simply isn't a visible factor in your chances of dying while flying, or indeed while doing anything else: it is insignificant, a problem that has been almost totally eliminated for Western citizens since its not-very-serious heyday in the 1970s and 80s, and you shouldn't worry about it. It would make absolutely no noticeable difference to your or my chances of violent death/injury if terrorism was eradicated overnight.
All of which makes me wonder why there is so much brouhaha from the one-eyed trouser snake to try and "fix" this "problem". Who is benefiting from all this security theatre if it's not us?