so they have absolutely no right to complain about aircraft noise.
Of course they have a right to complain. An airport is just a business that has to abide by environmental regulations like any other business. Indeed it is the public that make a special concession for an airport to extend its pollution outside its perimeter.
I'll be most of the local residents moved-in after the Sydenham Bypass was built, but they still have every right to complain about someone sounding their car horn between 23:30 and 07:00.