A320
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Workload
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented
Human Factors
Coming in to land [at] ZZZ. I was the PF and called for flaps full; bird off set runway track. I was turning base to final to land at an altitude of approximately 1500 feet. During the checklist reading as I was coming to my inside scan at the same time the Captain read auto thrust I looked down and noticed it was at thrust idle. I then pushed the thrust levers forward to TOGA and lowered the nose as the aural warning said 'speed'. The airplane slowed to around 125 knots; but quickly recovered to normal speed. Continued the approach without incident. Upon debrief on the ground at the gate the captain said that he accidentally turned his FD off and then back on which causes the airplane to go into thrust idle; when only one FD is on. Preventative measure could have been trying to configure earlier so as to not task-saturate the pilot monitoring.
A320 First Officer reported getting slow on approach when thrust levers were driven to idle by aircraft system logic.