Method and device for monitoring the ability to navigate of an aircraft during a phase of flight close to the ground

A monitoring device for monitoring the ability to navigate an aircraft during a phase of flight close to the ground, said aircraft using, for its navigation, positional information supplied by a satellite positioning system, said device comprising:

• setpoint selection unit in which a pilot of the aircraft selects a setpoint value for a height parameter, which is then used during said phase of flight;
• threshold determination unit that automatically determines an alarm threshold associated with the selected setpoint value;
• receiver that repeatedly automatically receives a current error value corresponding to an estimated current error of a current vertical position of the aircraft, which is supplied by said satellite positioning system;
• comparator that automatically compares each received current error value against the alarm threshold determined by said alarm threshold unit;
• alarm unit that automatically emits an alarm indicating that the current error value is above said alarm threshold;
• auxiliary determination unit that automatically determines, for each received current error value, a current auxiliary value expressed in the form of an achievable performance relative to said height parameter;
• a display screen that displays on a scale graduated according to height values:
• a first characteristic sign representing the setpoint value selected by the pilot;
• and
• a second characteristic sign representing the current auxiliary value determined by said auxiliary determination unit;
• and
• alert unit configured to emit an alert when said second characteristic sign comes within a predetermined height value of said first characteristic sign, with the alert being shown in visual format on the display screen;
• wherein:
• said alarm unit and said alert unit are configured such that, following a predetermined time after the alert is emitted by the alert unit, the alarm is emitted by the alarm unit if the pilot does not replace said setpoint value with a new setpoint value.