Going through security at Luton Airport I was standing next to a staff member, while she waited for the security people to push her wheelchair-bound charge through the metal detector. Unsuprisingly the metal detector detected that the wheelchair was made of metal. Well, d'oh! So the security staff had to pat down the elderly occupant of the wheelchair, to verify that she was indeed not attempting to smuggle contraband onboard.
I commented to the staff member standing next to me I'm surprised that they don't make plastic wheelchairs for airports. thinking that the time savings in security would actually make it worth the airport's while.
But on the plane I had a more interesting thought. Metal wheelchairs are a security hole. Metal wheelchairs "explain" why the detector trips, so they make a perfect distraction for smuggling naughty metal items on board. In fact, having one's leg in plaster would make one look far less suspicious as far as "looks-like-a-terrorist" goes. It's not possible for security staff to pat down inside a plaster cast, and it's about the most stupid thing you could try to do (the pain! the pain!). So it seems an ideal vector for a terrorist team to get items on board - conceal them in a genuine plaster cast for a fake injury, a cast which has some designed in weakness to allow it to be removed on-board.
I mentioned this last night to Andrea's friend Flo, and he observed that the whole 100ml liquids rule is utterly pointless, because it's totally subvertable. If one wants to take liquid onboard, one only needs to conceal it on tubes about one's person, somewhat like the Camelbak water-carrying backpack (no link, because their site is made of hate). It's not like the metal detector detects water. So what's the point of the "no liquids" rule - boost sales of bottled water airside?