The reason that I ask the question is that I have a booking that has encountered the dreaded summer schedule change. It is an international flight into the USA connecting to a flight to Canada. The original flight had a three hour window. The revised itinerary now has the connection down to an hour and a half. Given the present travel/security enviroment, this is really cutting too close for comfort. Hence my question: Are AC legal connections times realistic given present day travel challenges.