As GH said (also in a private message, not sure why but there you have it), they are cuter than most TSO’s. Not all for sure, I have seen some really ugly dogs working as BDT’s, but for the most part they have that warm fuzzy thing going for them.

Other than that he is pretty much off-base. Operating a Bomb Detection Team is quite expensive, far more so than a handful of TSO’s. And over time even more so than AIT systems. An effective BDT needs weeks of training, ongoing training, special facilities, special medical care, and much more. BDT teams are usually about 70% effective, and still require that the human part of the team know what their partner is telling them. They also have a limited service life each day. Usually in the area of 3-4 hours in any 12, and usually at best 30 minutes at any one stretch. They also have significant limitations on deployment. Crowded environments reduce their effectiveness to nearly zero, far too many distractions for the animal, and airports tend to be crowded environments. Aircraft fuel, being petroleum based, also affects the animals sense of smell, reducing their effectiveness even further.

Only one of these things affects AIT systems, and that is the operator learning to recognize what the device is telling them. And of course the occasional mechanical breakdown, but that is common with any man made device. There are far more effective places for BDT’s to be used, and the constant bustle of an airport is not one of them.

Metal detectors detect metal. The threat against an aircraft has far more dimensions than that posed by metal objects. Hence the need for AIT systems. As many have pointed out, hijacking is a significantly reduced threat now days, armored cockpit doors and reactive passengers pretty much make that a given (not that it is not attempted every now and again), the threat now is more closely related to explosives or biological/chemical exposures. Metal detectors just cannot detect those. AIT systems can, as long as the operator is on their game.