Plane cockpits designed to be ultra secure
EASA has recommended that airlines always have two people in the cockpit of a flying aircraftGetty istock

Europe's aviation authority has tightened its safety recommendations, urging all airlines to always have two people inside the cockpit of a flying aircraft, after a German co-pilot flew an Airbus A320 into a mountainside having locked the captain out in the cabin.

The European Union's aviation safety agency (EASA) said the change was in direct response to the crash of Germanwings Flight 4U9525, in which 150 people lost their lives.

"The Agency recommends operators to re-assess the safety and security risks associated with flight crew members leaving the flight crew compartment due to operational or physiological needs during non-critical phases of flight," EASA said. "Based on this assessment, operators are recommended to implement procedures requiring at least two person ... to be in the flight crew compartment at all times". One of two crew members has to be a pilot, EASA added.

Some European airlines, such as Germanwings' parent group Lufthansa Group, easyJet and Wizz Air had already committed to such security measures after it emerged that 28-year-old Andreas Lubitz, was alone in the cockpit when he put the A320 into a descent.

"While we are still mourning the victims, all our efforts focus on improving the safety and security of passengers and crews," EASA executive director Patrick Ky said.

The agency does not have any power to enforce its recommendations, which are usually strictly followed by the airlines. "If we do publish a recommendation, it is not easily ignored," EASA spokesman Ilias Maragakis said.

The procedure to replace a pilot who leaves the cockpit for the toilet or any other reason with another member of the crew was readopted in the US after 9/11 but it is not standard in Europe and Canada.