DESCRIZIONE
An ascent rate indicator mechanism includes a first wheel set and a pressure sensor. The first wheel set is connected to the pressure sensor driven in rotation by a pressure variation. The mechanism further includes a second wheel set driven by the first wheel set in a single direction of rotation from a start position into a measurement position corresponding to a decrease in pressure, uncoupling and return structure to be actuated at regular intervals to uncouple the second wheel set and to return it to the start position, an ascent rate display mechanism connected to the second wheel set and including an indicator member arranged to occupy, at each regular interval, a display position representative of the decrease in pressure during the interval, and synchronization structure actuated at each regular interval and arranged to maintain the display position of the indicator member during the regular interval.