Method for detecting an unforeseen event within an aircraft, said aircraft including a crew, said crew including a pilot, said aircraft being equipped with an alert computer capable of detecting the presence of one such unforeseen event, said aircraft being equipped with a main multifunction device arranged so as to face the pilot and at least two secondary multifunction devices (20, 30) that can be seen by the pilot, the main multifunction device and said secondary multifunction devices (20, 30) each including at least one screen (11, 21, 31) and a control computer (12, 22, 32), each screen (11, 21, 31) displaying an object, characterised in that said method comprises the following steps: - detecting the occurrence of an unforeseen event using said alert computer, and transmitting an alert signal indicating said unforeseen event to said main multifunction device and said secondary multifunction devices (20, 30), - following said occurrence of one such unforeseen event, placing at least one alert area on at least one of said main multifunction device and secondary multifunction devices (20, 30) as long as said unforeseen event persists by carrying out the following steps, it being possible to place each alert area in a first display mode or a second display mode, in which the alert area comprises at least one message that can be seen by the pilot and indicates said unforeseen event, or in a hidden mode, in which said at least one message cannot be seen: ∘ placing, in the first display mode, an alert area over said displayed object on said at least one screen of said main multifunction device, ∘ said crew requesting an acknowledgement control, and placing said alert area provided on the main multifunction device in said second display mode following said request, ∘ said crew requesting a reduction control of said alert area provided in the main multifunction device and, following said request for a reduction control: ▪ placing said alert area provided in the main multifunction device in the hidden mode, ▪ determining the presence of one such alert area in the second display mode on at least one of said secondary multifunction devices (20, 30), and ▪ if said presence is not determined, placing one such alert area over said displayed object on said at least one screen of one of said secondary multifunction devices (20, 30) in said second display mode. - detecting the occurrence of an unforeseen event using said alert computer, and transmitting an alert signal indicating said unforeseen event to said main multifunction device and said secondary multifunction devices (20, 30), - following said occurrence of one such unforeseen event, placing at least one alert area on at least one of said main multifunction device and secondary multifunction devices (20, 30) as long as said unforeseen event persists by carrying out the following steps, it being possible to place each alert area in a first display mode or a second display mode, in which the alert area comprises at least one message that can be seen by the pilot and indicates said unforeseen event, or in a hidden mode, in which said at least one message cannot be seen: ∘ placing, in the first display mode, an alert area over said displayed object on said at least one screen of said main multifunction device, ∘ said crew requesting an acknowledgement control, and placing said alert area provided on the main multifunction device in said second display mode following said request, ∘ said crew requesting a reduction control of said alert area provided in the main multifunction device and, following said request for a reduction control: ▪ placing said alert area provided in the main multifunction device in the hidden mode, ▪ determining the presence of one such alert area in the second display mode on at least one of said secondary multifunction devices (20, 30), and ▪ if said presence is not determined, placing one such alert area over said displayed object on said at least one screen of one of said secondary multifunction devices (20, 30) in said second display mode. ∘ placing, in the first display mode, an alert area over said displayed object on said at least one screen of said main multifunction device, ∘ said crew requesting an acknowledgement control, and placing said alert area provided on the main multifunction device in said second display mode following said request, ∘ said crew requesting a reduction control of said alert area provided in the main multifunction device and, following said request for a reduction control: ▪ placing said alert area provided in the main multifunction device in the hidden mode, ▪ determining the presence of one such alert area in the second display mode on at least one of said secondary multifunction devices (20, 30), and ▪ if said presence is not determined, placing one such alert area over said displayed object on said at least one screen of one of said secondary multifunction devices (20, 30) in said second display mode. ▪ placing said alert area provided in the main multifunction device in the hidden mode, ▪ determining the presence of one such alert area in the second display mode on at least one of said secondary multifunction devices (20, 30), and ▪ if said presence is not determined, placing one such alert area over said displayed object on said at least one screen of one of said secondary multifunction devices (20, 30) in said second display mode.