Under the tailcone of the Vulcan is the chemtrail dispersal system....
Well, no. Actually 'tis a Vulcan tanker (note the 50 sqn 'shagging rats' on the fin!) - and the object is the MFI wardrobe which housed the HDU. There are very few photos of the Vulcan tanker around - let alone near a Bear!
Can't really see that clearly, but isn't it a Bear C?
Aarrgh - Scroggs beat me to it! A good refuelling platform, the Vulcan. Much easier to prod than the Victor.