Interesting that this should generate controversy from ppruners stateside where guns are far mosr part of everyday life than in the UK. Interesting too that Egyptair was quoted as a reason not to arm pilots. At least some pilots in that country are armed. On a tourist balloon flight recently the pilot took out a shiny revolver from his briefcase and, in front of pax, tucked it into his waistband.
I'm also intrigued that some who oppose the idea are in favour of armed skymarshals -who have at least as much likelihood of turning rogue as us but are in the cabin with the risk of having their weapon taken by nasty people.