Heathrow Director, I do appreciate you've pretty much seen it all, but those 738's are blessed with an enormous amount of available thrust and if a captain wants to make a point of getting a nearly empty one heavenward in double quick time then if someone like me
is watching the second hand, they may indeed register a number as low as 20 seconds from application of what sounded like a goodly amount of power at one end of the runway to last rumble from wheels about halfway down. And with one as empty as ours, launching in not at all busy airspace up to FL400 is what the locos apparently
do with their
derring at every opportunity