the first time I saw the flight we were visiting my mother. We heared the sound of the engines and before anybody could even see anything mum looked up and said "they're Merlins" and sure enough the lanc came into sight with the spitfire and hurricane flying escort (a magnificen sight. I have to tell you) mum told us howt during the war she and my aunties would stand out at watching the bomber streams heading for Germany including one night when as she put it the flight seemed endless, which they found out later was the first 1000 bomber raid and then in the morning as they were going to work they would see them returning, often damaged. After that, as she said she'd recognise the sound of a Merlin anywhere