I have started recognising the sound of a Lockheed Hercules at 20,000 ft 10+ miles from me
. We get Spits from Biggin Hill flying a mile or so from us at 1,800 ft so anything loud gets my attention in the hope that it might be going over the top of us. We have had a variety of Herc's nearby in recent weeks including a civvy one.
During the pandemic, a Grizzly was doing circuits at Gatwick and we could hear that loud and clear
