VAPP : Final approach speed.
Displayed on MCDU APPR page.
Calculated by the FMGCs.
Represents : VAPP = VLS + wind correction.
The wind correction is limited to a minimum of 5 knots and a maximum of 15 knots.
The flight crew may modify VAPP through the MCDU. During autoland or when autothrust is on or in case of ice accretion or gusty crosswind greater than 20 knots, VAPP must not be lower than VLS + 5 knots.
VAPP TARGET : Represented by a magenta triangle.
Calculated by FMGCs
Gives efficient speed guidance in approach during various windy conditions.
Represents :
VAPP TARGET = GS mini + actual headwind (measured by ADIRS)
GS mini = VAPP - TOWER WIND (headwind component along runway axis calculated by FMGC from tower wind entered on MCDU).
VLS : Lowest Selectable speed.
Represented by the top of an amber strip along the airspeed scale on the PFD.
It is equal to : 1.13 VS, at takeoff
1.18 VS, when the flaps are retracted.
1.23 VS, when in clean configuration. (It remains at this value until landing).
VLS is corrected for Mach effect to maintain a 0.3g buffet margin.
In addition, VLS is increased when the speedbrakes are extended.
The VMC is taken into account for VLS computation as follows : At takeoff, until retraction of one step of flaps, VLS is equal to or greater than the lowest of :
V2/1.05
1.05 VMCA maximum certified.
In all the other phases, it is equal to or greater than VMCL.