A number of major Canadian, Norwegian, German and UK airlines have all pledged to change their policies.

The UK's Civil Aviation Authority (CAA) said it will "monitor the situation" as the crash investigation develops.

Lufthansa said that no matter how good the security, ultimately nothing could stop a rogue pilot.

Medical assessments

Air Canada, Westjet and charter airline Air Transat, Norwegian Air Shuttle, major German airlines including Lufthansa and Air Berlin, Easyjet, Monarch Airlines, Virgin and Thomas Cook have all confirmed they are changing their safety policies.

The change comes after UK airlines were told to review procedures following Tuesday's Alps crash in which 150 people died.

The new procedures will mean that two crew members must always be present on the flight deck.

The changes come after it emerged the co-pilot of Germanwings Flight 9525 had apparently locked himself in the cockpit before crashing the plane into the mountains below.

-BBC