CAMBRIDGE, Mass. (AP) - A Massachusetts Institute of Technology aviation analyst says U.S. flight regulations make it unlikely that a single jetliner pilot could barricade himself or herself inside the cockpit.

CAMBRIDGE, Mass. (AP) A Massachusetts Institute of Technology aviation analyst says U.S. flight regulations make it unlikely that a single jetliner pilot could barricade himself or herself inside the cockpit.

MIT expert John Hansman tells The Associated Press that U.S. safety procedures require two people in an airliner's cockpit at all times. Hansman says if the pilot or co-pilot of an American carrier leaves the flight deck for any reason, a flight attendant goes in.

Hansman says the regulations are designed to prevent a scenario in which the remaining pilot becomes incapacitated and can't open the door.

He spoke after European investigators said Germanwings co-pilot Andreas Lubitz barricaded himself inside the cockpit of an Airbus jetliner Tuesday and deliberately crashed it into a mountainside in France, killing all 150 passengers and crew aboard.