V1 for DRY/WET runway

[simonijs]

Moin,

I seem to remember, that in PSX the FMC computed V1 would change with the selection of DRY or WET on TAKEOFF REF page 2/2. However, in the past few very wet days, I did not see any difference between V1 DRY and V1 WET speeds, as calculated by the FMC.

Is my memory incorrect and has it always been like this?

Kind regards,
Simon

[Jeroen Hoppenbrouwers]

Uninformed guess ... if the runway is long enough, maybe it does not matter as Vr is "below" V1 in all cases?

[Hardy Heinlin]

Moin,

if the entered headwind is greater than 5 kt, wet/dry won't make any difference. Wet V1 varies with slope and headwind. Above certain limits wet and dry V1 become equal. At certain pressure altitudes, weights, flaps etc. there's no difference anyway, even if no wind and no slope is entered.

I guess you entered a headwind greater than 5 kt.

Also, you need to wait 40 seconds after situ file loading until the V speeds computer starts running; this is to avoid sudden weather changes which may autodelete the V speeds.


Regards,

|-|ardy

[simonijs]

Thanks Hardy,

Will check this out.

Regards,
Simon