TSR2 What is meant by
Above the line and
Below the line is that many check-lists have two parts, whilst other lists have only one.
For example, the Start Up Check List might (bear in mind I am not a pilot and am remembering conversations with my nephew who is) have 10 items that need to be checked BEFORE the a/c is pushed back from the stand. Then they pause at 'the dotted line'.
Once external signals are given, they continue the check list
below the dotted line which might have another 10 items that take them through 'push and start'.
There would be another short list to be checked as they turn onto the active runway, before they can depart and this will include adjusting their RayBan Aviator sunglasses, throwing the empty one pint coffee mug out of the side window and preparing to start the stopwatch function on their Breitling watch, so they call out "start the clock".
That could well be my last post ... 