In the late '80s, Britannia put some sponsored pilots through Trent Air Services as was (now Cabair). As part of the promotional / advertising / self publicity, Britannia flew a 767 into Cranfield. Don't know if they took everyone for a quick jolly or not.
I went to Cranfield (Trent) in 1988 and it was before mid-88, I would guess 1987.
HTH