10W, informative response, thank you for your input. We may had less leeway but we were parked adjacent the mid point of the departing runway on a self manouvering stand. It took us 5 minutes from start until take off run commenenced. ATC may see the bigger picture but on this day, the hold point was empty and we had a clear run down the taxyway so thats why this one stuck in my head and made me look on this forum to see if anyone else is having similar issues, to me it seemed they were penalising us by strictly applying their procedures when a month or so ago, this wouldn't have been a problem and we would've been underway within our CTOT. If we don't think we will make the slot then we request a new one or delaying action.
Bare with me as I only have a basic understanding on how the ATC network operates, as I understand our airline uses repetative flight plans and I don't think this system allows much in thought for aircraft weight/performance for optimum cruising levels, nor does it take into account various other factors that need to be applied on a day to day basis of operating the aircraft. Using the above system, then I doubt its feasible to apply such aspects to roughly 1300 plans per day. What it may lead too is operators filing at a higher level and us being capped by weight, which will just put strain on the upper levels predicted, and as you rightly said in your example, ATC ahead or CFMU won't know about it until we're airborne, of course, this is just an assumption but a view from the other side of the fence.
P.S. request runway 31!
