Weapon of choice
I have no idea what weapon or round but my vote would be for a S&W revolver - no problems with jams as with an auto pistol,simple & reliable as pointed out in previous post by Ilamas.
A low velocity hollow point round might provide ample stopping power ? I'm no expert & out of my province in the matter of firearms and the above suggestion maybe nostalgia.
I was trained in one day to safety & proficiency standard with the S&W 38 shooting from standing & kneeling on one knee position a long time ago. Seems to me that is all that is required - you don't need to be trained to Special Forces standard to be a deterrent to suicide hijackers.
The proposal seems inadequate but at least a step in the right direction.