Helophilus pendulous.

Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Syrphidae
Tribe: Eristalini
Genus: Helophilus
Species: Helophilus pendulous.
Flight Period: April - October

This is a very common species in the UK, where it is the commonest Helophilus species. The scientific name means "dangling swamp-lover".
Found around muddy pools and ditches. Most specimens can be identified by having at least the basal half (usually all except the distal third) the hind tibia pale yellow.
Taxonomy: