Having multiple flights blow up over the ocean simultaneously would be impossible to cover-up by the government. Doing this for arrivals would be much iffier as factors contribute to changing schedules (backed up traffic at destination airport, bad weather enroute)
True, but the triggers could be traveling with the bags and can be set to explode at the will of the suicide passenger.
I think blowing up over the ocean is the last choice.
IMO the intent was to at first blow up as they get over land in the United States and the last of the 20 or so getting off the ground might have been exploded over land in Brittan.
There are planes in the air right now that took off from UK before these new screening rules came into play.
Incoming...