Fighter jets were scrambled to help a plane flying over Portugal as its pilots struggled for control and planned to ditch in the Atlantic.

A few minutes after the Embraer 190 belonging to Air Astana had taken off from a maintenance facility near Lisbon, the crew used the transponder to “squawk 7600” – indicating a failure of communications – and shortly afterwards declared a Mayday.

For the next 90 minutes, the aircraft flew a terrifying course of repeated tight turns and sudden descents, as the airspeed and to 120mph, with a high risk of stalling.