Since 9/11, the United States has required at least two aircraft crew members be present in the cockpit of commercial planes during flight — but only in the wake of the Germanwings crash are foreign carriers rushing to catch up.

More than half a dozen airlines in Europe and Canada announced plans to mandate that pilots always have company, such as a flight attendant, whenever one has to leave the flight deck.

The rule change, which comes after news Thursday that the co-pilot of the doomed Airbus A320 deliberately crashed the plane into the Alps, was announced by carriers including Air Canada, British budget airline EasyJet and Lufthansa, which owns Germanwings.

“The safety and security of its passengers and crew is the airline’s highest priority,” Easyjet said in a statement.

Similar policies will be implemented on all German planes “as soon as possible,” according to German Aviation Association spokeswoman Christine Kolmar.

The Germanwings plane had numerous safety features in place, but all of them could be overridden by the person in the cockpit.

One feature allows pilots to use a keypad to get into the cockpit. The person inside hears a sound when the pad is used and can unlock the door for their colleague.

If the pilot is injured or incapacitated, that same keypad also allows a person to put in a “special emergency code” that unlocks the cockpit door. But someone already inside the flight deck can override the code, disabling emergency access for five minutes.