A British Airways flight issued a "mayday" distress call on its approach to Heathrow Airport earlier this month, according to a statement from France's accident investigation authority. The French Air Safety Investigation Authority, the BEA, said that as the plane approached Heathrow, there was a data system failure which triggered a stall warning. The crew then flew the aircraft in a different mode called "alternate law", which removes some automated flight protection systems. They issued the following statement: "The AAIB is investigating a serious incident involving a commercial aircraft which occurred on 6 July on approach to Heathrow airport." Aviation safety investigator David Gleave said there are different forms of mayday calls, and to send an urgency message was "not unusual".