I also worked at BA for a while. Everyone who worked for BA would glance at their watch when they heard it take off - the BA001 flight to NYC at 10am (I think? Or was it 11am?) was a good indicator of how smoothly our systems & the airport's were running - if it was late we probably had a problem.

Finally... coming in to land at the north runway you could see it directly overhead from the staff car park for Viscount House (where most of IT was based). The noise of it usually set off half the car alarms and you could see a huuuuge trail of dirty brown imperfectly burnt fuel with the engines throttled back.

Good times!

I now live ~10 miles from a relatively busy airport with business/charter jet traffic, and its barely noticeable to me. But lots of noise complaints in my town and neighboring towns.