Originally Posted by
Tarq57
We time it from the start of the take off run. Gives a level of consistency. There is a timer built into the strip board; when one departure is stamped as rolling, it starts counting up to three or four minutes, depending on the WT category.
I guess it probably should be timed from the respective rotation points, but there's not that much variation in time type to type, from start of TO run to rotate...maybe a max of 30 seconds for, say, a lighty behind a heavy. (Could be more if it's something like a Cub following an IL76).
Nup. It's the time at the rotation point, as you acknowledge. Nothing to do with when your system starts timing the takeoff roll. Why would your system capture that parameter anyway? What is its purpose?