Denmark's transport minister says a recommendation will be sent Friday to all airlines with a base in the Scandinavian country to have two people in the cockpit when in the air.

Airlines and officials around the world are starting to impose the rule after details emerged that the co-pilot of Germanwings Flight 9525 had apparently locked himself in the cockpit and deliberated crashed the plane into the mountains below.

Transport Minister Magnus Heunicke said in a live television interview with the TV2 channel that the Danish Transport Authority also would review all physical and mental tests of pilots flying to and from Denmark. German news media have depicted co-pilot Andreas Lubitz as a man with a history of depression who had received psychological treatment.