I have covered the tan coloured Beaufort survival waistcoat on the blog a few years ago here. This was not the only variation in the vest however, and it was also produced in olive green as well:

This vest follows the same design as the previous example, but in green, so we have a selection of pockets for survival supplies across the front:

And a small holster for a PP pistol on the left breast:

A pair of small pockets are sewn to the shoulders:

On the rear a pair of tapes and buckles allows the waistcoat to be adjusted to size whilst leaving the back clear to make it more comfortable to wear when sitting down:

The date inside this waistcoat is 2009, much later than the other one I have and indicating that the design remained in manufacture for many years:

As far as I can work out, this waistcoat was issued to aircrew rather than pilots and so would have been used on transports etc. More typically single seater fighter crews had vests with integral lifejackets. The lack of a lifejacket here indicates that it was issued separately and might only have been donned in an emergency. As this takes some space to do, the conclusion is that the users were in a larger aircraft such as a transport. Despite the longevity of these waistcoats, I have struggled to find any photos of crew wearing them so if any reader can help out with more context, please comment below.