It’s all over the news, with mobile phone pictures and everyone being interviewed. Although it’s clear one engine was in flames, one of the interviewees mentioned something really interesting that the main news media hasn’t picked up on yet…
Apparently the engine cowling became detached from both engines, after which the pilot assessed the situation with both engines running properly without covers. Only after one of the engines caught fire was the emergency landing made back at Heathrow. (This is reasonable – there are other places to land for less of an emergency and the crew might have wanted to assess the situation as to why they’d lost the covers before landing).
To lose one cover is unfortunate; to lose both is starting to look like carelessness.
It could be that the passenger being interviewed was a poor observer, or it could be that the covers were simply not latched on properly. It’s been said by the BBC people that “the covers were blown off” – engine explosion? Not likely, as apparently the engines remained running.