Airport security scans, etc can only go so far.
I travelled a lot by air in the 1970's as an employee of TWA(now extinct). Took parents to Israel soon after the 6 day conflict when hijacking was in vogue.
In what I now consider a truly genius strategy, as part of a reasonable security check, all passengers were told all El- Al flights had a unidentified air Marshall passenger with full authority to use deadly force if needed. Even the crew did not know which passenger this was. Talk about feeling safe!!
Job opportunity for select military trained professionals??