Re noise complaints. I was in Head Office DCA Melbourne in the late Sixties when noise complaints were continually annoying a local Member of Parliament whose electorate was under the Sydney 07 ILS flight path.
In those days the ICAO standard ILS was set at about 2.5 to 2.75 degrees. My boss Lloyd Milne (former wartime Hudson pilot) was told by his boss Sir Donald Anderson (via the chain of command of course) to suggest a solution. After all it was a political issue. Lloyd scratched his head and came up with the idea to increase the glide slope angle up to three degrees which approached the upper limit for a jet transport approach without increasing the rate of descent too much. The theory being three degrees would mean a steeper angle of approach, therefore less power and less noise foot print. I think it added about an extra 150 feet to the outer marker crossing height four miles out.
The local Member for the Outer Marker (I think it was Padstow) constituency was pleased about that idea, even though we didn't tell him it made no practical difference to noise levels. But he could tell the great unwashed in that area that he had acted to fix the problem. It was a real vote getter which is what it was all about in the first instance.
So for weeks to come we flogged the DCA Flying Unit DC3 VH-CAN and F27 navaid calibration aircraft down the 07 ILS having got the techs to jack up the glide path to three degrees. We did Sydney 16 ILS as well.
The idea took on and next we knew the order came down the line to jack up all the Australian ILS from 2.5 degrees to three degrees. That took a lot of traveling between the major airports of Australia including Darwin. ICAO heard about all this and thought it was a splendid way of reducing noise footprints.
Eventually three degrees slope became the standard we have today. You can thank the Labor Member for Padstow for that. It was all a bit of a wank but it fooled most people I think. Whether the number of complaints reduced I have no idea. But something was seen to be done and that was the main thing. The unintended consequences however proved time consuming and expensive in terms of time and money.
You see, it was considered a bit untidy to leave the T-VASIS all over Australia at 2.5 degrees and the ILS at 3 degrees. So we loaded the DC3 and F27 with our theodolites, insect spray, wide floppy hats with corks and sunscreen and even snake bite outfits, and flew all over Australia to recalibrate the numerous T-VASIS to three degrees.