It is not very difficult to disconnect the pump from the canula - after all I have to do that when I shower, but obviously when I do, I'm not getting insulin. The instructions I had from my doctor and pump instructor are essentially to keep the pump on and running except when necessary. I specifically asked about airport security and was told to keep it on. This is confirmed by the manufacturer's manual, which says that it should be kept on during security checks and that in most cases it will not alarm.
Of course disconnecting the pump from the canula does require me to remove (at least partially) my shirt. I doubt that would be acceptable.