“””But the [des_TFC] does seem to indicate “destination” doesn’t it? Alternate interp for “des”?”””
Another guess: destination traffic delay
That makes more sense if the flight was from Heathrow to Washington area.
I didn't find any indications the route went through Italy.
Hey, we're pretty good amateur planefags, right? Maybe we'll get our Roger Ramjet wings out of this one.
Bagster