Thank you Vilas. I just played with the numbers on the ground in the MCDU and the VAPP will indeed vary depending of the ZFWCG inserted. I went from 25% to 10% and the VAPP increased by 3kt. I think if you leave it blank it might assumes 25%. I remember on the older Honeywell FMGC it was by default 25% the ZFWCG value.