C, the explosion was heard 24 secs after the flash in the sky. That's exactly 27,000

[Sir C]

I didn't know that. But this Graun video shows the flash, and then says the boom is heard 24 secs later.

https://www.theguardian.com/world/vi...an-plane-video

Now I worked out the speed of sound at 24 secs and converted it to feet and it's exactly 27,000 ft.

I know that it wasn't directly above so the sound wave would have moved horizontally as well as downwards. But that does seem a very round number. That flash was exactly 27k ft away from the camera that filmed it.

27,000' is about 5 miles, you daft bugger.