Effect of wet runway on ASDR
 

I have searched for this but have yet to get my head around the situation.

Compared to a dry ASDR the wet ASDR will be affected by reduced braking action requiring an increase in ASDR. However 2 factors that counteract this are that a wet V1 is typically used so the aircraft has less speed and energy to dissipate. Also, on a wet runway reverse thrust is permitted to be considered for stopping so would total braking action not be better on a wet runway than dry with wheel brakes only?

So does a wet runway make ASDR increase or decrease?

Actually it can make it DECREASE thanks to the use of reverse thrust and lower screen height! THis is one of the reasons that software has a parameter restricting Wet takeoff weights "equal to" or "less than" dry takeoff weights.

Mutt

I don't see no relation of a screen height n asdr except when u compare it with a todr or a tor, but your wet asdr = greater of the dry both engine, 1 engine or a wet asdr calculation.

Paragon,

screen height is 15 ft for a wet runway, instead of 35 feet for dry. Mutt has it right. Note that he says "can", and not "will".

Screen height isn't relevant for ASDR, as you're not getting airborne.