When you consider the many noise complaints these days and that most flights operate between 06.00 and 23.00, the old days of very noisy passenger flights heading off in the early hours would give today's complainants white hair! I remember VC-10's coming out of LHR heading eastwards at 9/10pm at night and the sound of the Conways reverberating for quite some time long after they'd passed overhead. At 2am it would have been disruptive to all slumbering souls.