French investigators have disclosed that the stall-protection system activated on an Air France Airbus A320 during the final stages of an approach to Marseille.
The aircraft had been operating a domestic service from Paris Charles de Gaulle on 11 March, says the French investigation authority BEA.
Surveillance data indicates that the aircraft (F-HBNE) started descending towards Marseille from the northwest as it passed Clermont-Ferrand at about 14:00.
BEA says it was performing a visual approach to runway 31L - requiring the aircraft to pass the airport and turn back - and that the incident occurred as the aircraft made its final turn.
"High angle-of-attack protection activated," says the BEA in its weekly bulletin, without further detail on the circumstances. The aircraft descended to a minimum height of 700ft (210m).
Meteorological data from the time of the incident, around 14:30, confirms good visibility and winds of 9kt from the west.
BEA says the crew executed a go-around before performing another visual approach and landing. None of the A320's occupants was injured.
Marseille has two parallel runways, of which 31L is the shorter at 2,370m (7,776ft).