So all these night time arrivals are throttled back to minimum and they are practically silent you say? This is obviously a procedure that I was never aware of! Quick mathematical calculation then for the airborne experts. A320, descending through 3000ft with idle power setting over BT9 after coming up P620 from Dublin direction for downwind leg runway 25 at Aldergrove. Are you telling me it can continue in noise stealth mode with no adjustments required all the way to the threshold? Now that's impressive!
