Effect of runway slope on ASDR
I did a search here but couldn't find anything with details on the effect of runway slope on ASDR.
I was thinking about calculating it out using Newton's laws of motion but it's a little more complicated than that! On a down slope runway compared to a level runway you would have an accelerate distance that would be shorter due to the higher acceleration rate and the reduced rolling resistance due to the weight of the airplane not acting perpendicular to the runway. Stopping would be longer compared to a level runway because you have to oppose the component of gravity accelerating you along the runway, less weight acting perpendicular to the surface means the wheels don't have the same contact and you would be restricted to less brake force than on a level runway. Percentage wise, when on a level runway, accelerating up to a speed takes more distance than stopping from that speed but that relationship would start going the other way with an increase in downward slope so that eventually you would have the accelerate distance shorter than the decelerate distance. What slope does that happen at? Too many factors to determine it!
Based on that I think it would be hard to accurate calculate how ASDR would be affected. Does anyone have any charts that show the effect?
Edit: I should clarify that for this example V1 is not changing. Any data for either all engines operating or one engine inop ASDR is welcome.
Last edited by italia458; 22nd July 2012 at 09:01.