A flight control computer of an aircraft is likely to operate in a so-called incidence protection mode in which it is configured to compute the deflection orders of an elevator as a function of incidence angle values supplied by a set of incidence probes, so as to keep the incidence angle of the aircraft within a range of acceptable incidence angle values. The flight control computer is configured to, when only one incidence probe is operational: compute a first estimated incidence angle value of the aircraft, by a first estimator and a second estimated incidence angle value of the aircraft, by a second estimator unlike the first estimator; and keep the incidence protection mode activated as long as the incidence angle value supplied by the single operational incidence probe is consistent with at least one out of the first estimated incidence angle value and the second estimated incidence angle value.