London, Jumada II 7, 1436, Mar 27, 2015, SPA -- British authorities asked airlines to review flight procedures on Friday but defended their system of pilot health checks amid concern that some airlines conduct only cursory mental health assessments, dpa reported. The review came as German investigators said the co-pilot of the Germanwings flight, Andreas Lubitz, who had been treated for mental health issues, appeared to have had hidden a recent illness from his employer. Britain's Civil Aviation Authority (CAA) said it was coordinating its response with the European Aviation Safety Agency (EASA) and has "contacted all UK operators to require them to review all relevant procedures" following Wednesday's Germanwings crash. "All UK airline pilots undergo extensive and regular medical assessments to determine their fitness to hold a licence," the CAA said. contracts for crew on European aircraft." "An alarming number of pilots are working with no direct link to the airline they actually fly for, with some airlines - especially in the low-fares sector - drawing significantly upon a 'casualized' workforce," said a statement from the European Cockpit Association, which represents pilots. Emmanuel Jahan, who heads the European civil aviation group that commissioned the survey, said the results showed that "casualized" pilots were "worrying about their working conditions and where to pay their taxes and social security." -- SPA 18:21 LOCAL TIME 15:21 GMT www.spa.gov.sa/w