I've probably used some incorrect technical terms here, but the broad concept is about correct, I believe - if not, then I'll stand to be corrected
Essentially what I was wondering was is it just a trim issue or is it actually to do with staying within the weight and balance envelope - the light aircraft I fly have a fixed envelope that is the same for all phases of flight....but it is possible that airliners have an envelope that expands after take off to allow a greater range of weight distribution?