Disregard 7478's post about A330/340 - on the A320 we select FLAP 3.
But the speed is mentioned in the FCTM in "CONSEQUENCES" where it says..
The selected speed must be used
My (old?) QRH says in the notes
Approach with selected speed is recommended
The reason is the ABNORMAL Vapp calculation QRH 2.31 - up to ΔREF of 20 kts we add a wind correction and insert the figure on PERF APP page. If you select managed speed GS mini might increase Vapp above this figure and compromise your careful landing distance calculations.
7478
what about if we have to carry out an overweight landing? i guess we can use managed speed to take advantage of GS mini in this scenario. it's not mentioned in the QRH though whether the approach is to be flown at selected or managed speed.
Don't know about the A330/340, but in the A320 you have to select VLS as your target speed in the final approach stages.. and it says
Reduce the selected speed on the FCU.... in the QRH. But surely as a general principle if overweight you do not want excess speed on short finals?