| Green Cactus, I was afraid that some-one would bring that up, which would then require a more comprehensive explanation of "it all depends". It all depends upon the vintage of the aircraft and the certification standards required. As oldebloke has pointed out "Sorry I should have said that only the B777 has demonstrated the 'wet' acc/stop..", more modern aircraft have fully accounted for wet runway considerations at the time of certification, and typically, the Wet Runway charts are for Balanced Field, which, at least in theory, means that Accelerate-Stop and Accelerate-Go are equal. Another mode of certification in recent aircraft is full accountability for Wet Runway Stop or Go, not Balanced Field, but one set of charts providing limits for the most limiting of Stop or Go. For the daily user, there's little to indicate which factor is limiting, for the "Performance Nerds" (like myself), careful examination of "break-points" on the charts will indicate when either Stop or Go is more limiting. Yet another earlier mode is the provision of Accelerate-Stop Charts, and Accelerate-Go charts, calculation of both limits, and limiting Takeoff weight to the least of the two. In this case, it will be clearly evident to the user whether the Wet Runway takeoff is Stop or Go limited. In even earlier generations of aircraft, when wet runway performance was not considered at all, later "wet runway band-aids" were applied to dry runway V1s, with asociated performance penalties. These band-aids were primarily directed at the Stop case, but the better manufacturers would oft provide corrections for the Go case if the (usually nominal) V1 reduction was applied. If no correction was necessary, you were Stop limited, if further weight reductions were necessary, you were Go limited. As stated at the beginning, "It all depends" (upon the era when the aircraft was certified). Best Regards, Old Smokey |