Just like how the seat cushion doubles as a flotation maybe arm rests should dispense 8 in knifes. Not much advantage to sneaking a weapon on a plane if everyone else has one too.

Oh yes, we don't want violence on the plane so just give everyone weapons

Frankly this is the asinine US view which results in so many shootings because there are just so many guns floating around basically unrestricted

We could Home Alone it instead!

Trip wire between the seats. Instead of those oxygen masks it's a hammer that swings down. Hot iron on the bathroom pull handle.