Go-around with a reduced thrust (Soft Go around)

Go-arounds usually take place when an aircraft’s weight is well below the Max Landing Weight, and of course, when flying at a low speed close to the Approach speed (VAPP). Application of the TOGA thrust under these conditions creates an unusually strong longitudinal acceleration. Such a strong acceleration is rarely experienced by flight crew since the only other time TOGA thrust is applied is at take-off when the aircraft is heavy.

Flight crew are not used to the feeling of such a strong acceleration, so this may lead to them being surprised. The strong longitudinal acceleration induced by the TOGA thrust may ultimately lead to Spatial Disorientation (SD) of the flight crew caused by a Somatogravic Illusion (SI). SI is a suspected element in several fatal accidents.

As a means to reduce the likelihood of SI occurring, Airbus developed a function that allows crews to perform a go-around with a reduced thrust, adapted to the aircraft weight, speed and altitude: the Soft Go-Around Function (SGA).

based on the environmental conditions, the aircraft weight, altitude, speed and slats/flaps configuration, the Auto Flight System (AFS) via the FMGCs computes a thrust target that will enable the aircraft to climb at 2000 ft/min) This thrust target is then sent to the engines FADEC that will apply the optimized thrust as soon as the function is activated via the thrust levers.

When the go-around is initiated, the flight crew sets the thrust levers to TOGA position, as usual, to trigger all the logics (approach modes disengagement, FMS FPL sequencing…), and then activates the SGA by moving back without delay the thrust lever to the FLX/MCT detent. Like any mode, the flight crew checks the engagement of the SGA via the FMA

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