A British Airways Airbus A320 made a mayday call on approach to Heathrow on 6 July after two stall warnings, then landed without further incident. The flight had come in from Dusseldorf airport in Germany, and the emergency call was later tied to a serious incident under investigation by the UK's Air Accidents Investigation Branch.
That is why the case is drawing attention now. A mayday is the strongest distress call a crew can make, yet the aircraft still completed the landing safely. The AAIB said it was looking at what happened on the approach to Heathrow, where a commercial aircraft was involved in a serious incident earlier this month.
The French Air Safety Investigation Authority said a data system failure triggered the first stall warning as the plane neared Heathrow. After that, the crew flew the aircraft in alternate law, a mode that removes some automated flight protection systems. Another stall warning followed at 3,000 feet, and the urgency call already made by the crew was upgraded to mayday, signalling imminent danger even as the aircraft kept coming in.
David Gleave said mayday calls can take different forms and that sending an urgency message is not unusual. He said a captain can decide to use that call if there are sick passengers needing urgent medical attention, though he added that it is very unusual for a call to reflect a significant failure on board the aircraft. That gap between the strength of the distress call and the fact that the flight still landed safely is what makes the event stand out.
The AAIB said the case would be handled as a correspondence investigation, meaning no team would be sent to carry out field inquiries. The remaining question is not whether the flight landed safely — it did — but what exactly triggered the data system failure, the stall warnings and the decision to move the aircraft into alternate law on an approach that was likely only miles from Heathrow when the second warning came.
