Heli noise footprint
Hi Rotorheads,
In the area that I operate from we are blessed, to be able to see a lot of o/head traffic covering nearly every Heli that op in the UK, so far as my little test have turned out the 109 Power and the 500D have by far he greater footprint of any that I see, in fact the 109 Power seems to be the outright winner, its noise signature and prop beat can be heard on average for at least 10 miles, by comparison the Twin squirrels hardly ever put out a prop beat but a very noisy gearbox , that seem to anounce itself at about 6/7 miles, The Gazelles again have hardly any prop noise but that high pitched gearbox noise but only announce themselves at about 2 miles, now my little observations are only done by using local knowledge of land, and being able to recognise the Helis involved, my question is< are there any limitations to noise footprint( apart from the Noise regs in Dbls) and do other people find particular Helis noisy as well, and, is the prop beat avoidable, by easing back a little on the power ?