Airbus performance question
Dear Friends ,
I am a little bit confused with a peformance issue which I encountered today regarding selecting the takeoff speeds in Hamburg :
Our actual takeoff weight was something around 72 tons ( A321 ) , and Config2 speeds were : 112*/134/136. Runway was reported as wet on the ATIS , so the wet corrections as for the speeds were : -8/-3/-3 .
Min. speeds at the right bottom of the RTOW chart were 112/../.. ( I cant not recall the exact V2 and Vr speeds atm which are not relevant with my question )
So , as we all know , asterix on V1 speed was for to draw our attention that mentioned speed is below min V1 value at the bottom of the chart , which is ok. As far as I know , airbus states that , there is no need to check speeds against min values at the bottom of the RTOW chart up to more than 1 corrections applied. So , when we deduct 8 knots from 112 , then we go to 104 knots , which seemed a bit unusual. And when I tried to enter this value for V1 on PERF page , MCDU gave a warning message that the speed was too low.
So , we decided to stick with the min 112 knot value.
The question is , why did the aicraft had generated that kind of warning message or have we missed something with the performance calculations ?
Thanks in advance for you comments.