Cambridge: US flight regulations make it unlikely that a single jetliner pilot could barricade himself or herself inside the cockpit like French prosecutors say the Germanwings co-pilot did before crashing his airliner into the French Alps, a Massachusetts Institute of Technology aviation analyst has said.

MIT expert John Hansman yesterday said US safety procedures require two people in an airliner's cockpit at all times. If the pilot or co-pilot of an American carrier leaves the flight deck for any reason, a flight attendant goes in, he said. "The reason for that is in case the remaining pilot becomes incapacitated and couldn't open the door," he told The Associated Press.