A bomb that size would be very unlikely to take down a plane (remember, blowing a hole in the fuselage doesn't cause people to fly out, despite what the movies show), so it seems the most likely use for it would be to try and blow open the door to the cockpit so they can take over the plane.
Regardless, though, it's incredibly stupid for the US to even consider this ban. The chances of success are extremely small compared to the headaches this will cause.
Regardless, though, it's incredibly stupid for the US to even consider this ban. The chances of success are extremely small compared to the headaches this will cause.