Anyone who photographs dragonflies will take you how difficult flight shots are. There are one or two exceptions to this - some hawkers will hover for a few seconds giving you just enough time to aim, focus and press the shutter. Nevertheless, it takes some practice.
They are fairly common in southern England, and their numbers are boosted by an influx from the continent. They are in flight from July to October (or even November).
This photograph was taken from Bernard's Hide whilst I was waiting for a kingfisher to appear. It hovered right in front of me in the sun, on several occasions. There's a lot of criticism about the ability of Pentax cameras to focus on birds (or dragonflies) in flight, this was one of several taken with my Pentax K3ii the Pentax D FA 150-450mm F4.5-5.6 ED DC AW lens, and in my opinion the detail is excellent, whilst people sitting next to me with their Canons and Nikons were complaining that they couldn't capture any shots. Don't write off Pentax!