<< I've seen a few do a full 180 inside 2nm from 27R>>
There was a certain A330 from the Gulf region that did it a few months ago and raised a lengthy post here on pprune. Saw it myself - very very very impressive MAP - and was not surprised so many commented on it. I'd say a white knuckle arm rest grip for the PAX. Heading east along the Great Western lines overhead West Drayton open prison!
Have since seen a couple of other 180's - not quite as tight - though certainly heading east by overhead Hillingdon Hospital.