A piloting assistance process for an aircraft upon a landing phase on an airport being provided with a plurality of landing runways, said aircraft being provided with an automatic braking system being able to automatically brake the aircraft on the ground depending on a selected braking mode, said automatic braking system comprising a plurality of different braking modes respectively performing different strength brakings, process according to which: a) one of said landing runways of the airport is determined, being intended for landing of the aircraft; b) characteristics of the landing runway determined in step a) are automatically determined; c) the usual position (Pc) of the aircraft is automatically and repeatedly determined in a reference point (Rp) connected to said determined landing runway; and d) as soon as the aircraft flies at a given height above said determined landing runway, automatically: d1) using at least said usual position (Pc), a minimum braking distance is estimated representing the distance along the landing runway until the aircraft stops on this landing runway; d2) this minimum braking distance is compared to the length of said determined landing runway; and d3) if said minimum braking distance is higher than the length of said determined landing runway, and as long as this is the case, at least one alarm is automatically emitted in the cockpit of the aircraft, the following operations being performed in step d1), for estimating the minimum braking distance: - by means of the current position (Pc) of the aircraft compared to the standard descent plane, a distance APD is calculated being relative to an air phase above the landing runway; - by means of said performance model, a ground running distance GPD is calculated between touching the ground by the aircraft and the final stop of said aircraft; and - the sum of said distances APD and GPD is calculated for obtaining a minimum braking distance, from which the longitudinal distance between the current position of the aircraft and the threshold of the runway is deducted for obtaining the minimum braking distance, characterized in that in step d3), an alarm is emitted for informing the crew that the braking capacity of the currently selected braking mode on said automatic braking system will not be sufficient for safely stopping the aircraft on said landing runway and lead them to select on said automatic braking system, a braking mode with a braking strength higher than that of said currently selected braking mode. a) one of said landing runways of the airport is determined, being intended for landing of the aircraft; b) characteristics of the landing runway determined in step a) are automatically determined; c) the usual position (Pc) of the aircraft is automatically and repeatedly determined in a reference point (Rp) connected to said determined landing runway; and d) as soon as the aircraft flies at a given height above said determined landing runway, automatically: d1) using at least said usual position (Pc), a minimum braking distance is estimated representing the distance along the landing runway until the aircraft stops on this landing runway; d2) this minimum braking distance is compared to the length of said determined landing runway; and d3) if said minimum braking distance is higher than the length of said determined landing runway, and as long as this is the case, at least one alarm is automatically emitted in the cockpit of the aircraft, d1) using at least said usual position (Pc), a minimum braking distance is estimated representing the distance along the landing runway until the aircraft stops on this landing runway; d2) this minimum braking distance is compared to the length of said determined landing runway; and d3) if said minimum braking distance is higher than the length of said determined landing runway, and as long as this is the case, at least one alarm is automatically emitted in the cockpit of the aircraft, - by means of the current position (Pc) of the aircraft compared to the standard descent plane, a distance APD is calculated being relative to an air phase above the landing runway; - by means of said performance model, a ground running distance GPD is calculated between touching the ground by the aircraft and the final stop of said aircraft; and - the sum of said distances APD and GPD is calculated for obtaining a minimum braking distance, from which the longitudinal distance between the current position of the aircraft and the threshold of the runway is deducted for obtaining the minimum braking distance,