Seen this evil looking Robberfly recently on a few occasions. It is the Hornet Robberfly, Asilus crabroniformis. They are really big & obvious once I got my eye in, due to their pale brown colouration & large size (About an inch long). Quite often I saw them basking on dried horse dung on Downland. The larva live around these dung pats for a couple of years, before hatching out in June. The adults will be on the wing till around the end of Oct. Their prey includes Grasshoppers, Beetles (especially Dung Beetles), Bees, Wasps & other Robberflies. They sit around a lot as they hunt from low perches or the ground. Other delightful facts is they can take 10 - 30 minutes to suck out the contents of their latest prey item. But don't worry they aren't known to attack humans.
They are fairly widespread over the Southern counties of England, especially South of Bristol to the Home counties. After that records seem to become more scattered heading into Wales, the Midlands & East Anglia, with just the one site in North Yorkshire.
The great advantage of carrying a camera around nearly all the time I am out, is it allows me to quickly grab a photo of something like this & then try & figure it out later.