Definitely an L1011, for absolute certain. I flew on those exact services a good number of times from 1988 until mid-1991, and the type was always a TriStar 200 or 250.
I don't think Delta ever used series 500s on the CVG
run (barring equipment substitutions), although once or twice I did notice 500s on the ramp at LGW
. Either way, it's beyond question that until the 1990s the only basic type Delta ever used on UK flights, whether from ATL
, was the L-1011 TriStar.
If you tell us the seat allocations, it might at least be possible to settle whether the particular TrisStars they flew on were short-body 500s or one of the standard-body models.
There's a faint chance I might actually have been on one or other of the flights your grandparents took, JetJock22. Like many of us, I have all my flights recorded. It's a stunningly long shot, but it might be worth telling us the precise dates... Who knows? Maybe I could clear this up for you, real pronto!