Air traffic controllers at Heathrow airport failed to understand two distress calls from an Italian airliner carrying 104 people because the pilot's English pronunciation was poor. A report published today will reveal that the Alitalia jet suffered a near complete loss of its navigational equipment in its final approach to London.
The control tower did not understand a mayday message from the plane's captain and did not initiate usual procedures, which include putting the airport fire service on alert and clearing the runway.
Although the plane, which flew from Milan, landed safely the incident is likely to prompt concern about the quality of English spoken in cockpits. Low-cost airlines are looking increasingly far afield to recruit crew, who routinely speak English as a second or third language.
The Air Accidents Investigation Branch said the Alitalia Airbus A320 left Italy last year with one of its navigation systems out of order. On the plane's final approach to Heathrow, a second navigational system failed and the landing was aborted.
While circling the pilot transmitted an emergency message known as a "pan-pan" call and reported the failure. But air traffic controllers did not understand until another aircraft intervened. The report said the pilot had to land manually on a "point and shoot" basis and transmitted a more serious mayday call asking for priority.
The report said: "The mayday element of this call was not heard by the controller. This was probably due to a combination of the commander not announcing the mayday using the expected protocol and his heavily accented English, rather than any failing within air traffic control."
Language skills of aircraft crew have become an issue in the industry as budget airlines have scrambled to find staff for rapidly growing fleets.
A spokesman for the British Airline Pilots Association said: "Balpa is concerned whenever there is a case of English not being properly spoken or understood. There are sometimes cases like this, although thankfully they're very rare." He said there was a back-up system in most jets allowing pilots to use an electronic distress "squawk" instead.
An Alitalia spokeswoman said the incident did not put passengers' safety at risk.