A British Airways flight issued a "mayday" distress call while on approach to Heathrow Airport on July 6, following two stall warnings.
The Airbus A320 was flying from Dusseldorf, Germany, when the incident occurred. France's accident investigation authority stated that a data system failure triggered the first stall warning as the aircraft approached the London airport. The crew then switched the aircraft to "alternate law," which disables some automated flight protection systems.
A second stall warning occurred at approximately 3,000 feet, prompting the crew to upgrade their urgency call to "mayday," indicating imminent danger. The aircraft, however, landed without further incident.
The UK's Air Accidents Investigation Branch (AAIB) confirmed it is investigating the serious incident. British Airways stated it is cooperating with the AAIB's investigation and cannot comment further at this time.
The BEA, France's air safety investigation authority, released a statement regarding the incident, which the AAIB would not confirm as originating from them. The AAIB stated its investigation would be a correspondence investigation, meaning no field team would be deployed.
Aviation safety investigator David Gleave noted that while pilots have discretion on issuing urgency calls for various reasons, such as medical emergencies, a mayday call due to a significant onboard failure is unusual.