Was driving past Northolt this morning looking at a Gazelle preparing to take off. I was just thinking about back in the day when I was a lad when above I noticed a Merlin was flying towards central London. I didn't think much of it at first but what was it doing there? It was above central London exactly when the first explosion happened. This isn't a conspiracy theory just wondered why a Merlin would be over London. Can anyone clear this up? Thanks.