I have a huge problem with all the panic that happens every time a ‘terrorist’ manages to make a half-witted attempt at blowing up a plane…
True terrorists have no qualms about going on suicide missions, but are frequently screwed by being really bloody unintelligent. There’s are sure-fire way of getting a bomb on board a plane, which nobody would be able to do anything about, and which current detection methods can’t even track.
Basically, whenever patients go through major surgery which includes installing hardware (Say, a knee or hip replacements), they are issued with a letter from a doctor stating that they have metal embedded in them, and that this might cause a metal detector to go off. If you’ve ever seen an x-ray image of a bilateral hip replacement, you realise that these are pretty high-end operations, which involve huge amounts of metal to be inserted in someone’s body.
As such, once the surgery is healed, all you have to show for it is some awesome surgery scars, and setting off metal detectors.
Because these patients have to get through airports somehow, they are issued with letters from the doctor explaining why they have detectable metal in them.
Now, you don’t actually need a lot of explosives to take down a plane – high explosives are remarkably potent.
Combining all the points above: There are a lot of places in a human body where you could hide a bomb. Simple options that even a less skilled surgeon would be able to complete is the abdominal cavity, or to remove a lung and place the explosives there. If you want the surgery scars to be healed before the terrorist boards the plane, you obviously need a surgeon who is skilled enough to keep a passenger alive for eight to ten weeks after the operation, but if you don’t care about that (and, as a terrorist, why would you), a botch-job would do.
More advanced, it would be possible to do an actual hip replacement, and use an long, hollow piece of metal in the body, filled with the explosives, a trigger mechanism etc. Shy of doing an actual X-ray (which they don’t do at airports… Yet), this would be completely indistinguishable from a real hip replacement. Again, if you’re a terrorist, you don’t give a damn if you’ll ever actually be able to walk again: A wheelchair and a ton of pain-killers would get you through security and to the airplane, and from there onwards, well, who cares.
In short: Everything we’re doing at airports right now is done to keep us scared, and to cover air travel with a thin veneer of security blanket. It’s hogwash: We’re not 100% safe. But then, we never will be. What annoys me more than anything is the crumpling of privacy and personal liberty we’re willing to accept in the name of (an illusion of) safety.