Apparently an AN-12 (UR-CKL) just flew over me at 22000' and I didn't hear it...
Another memory from the days of yaw... JAT AN-12s had a weekly freight flight out of Heathrow, Saturdays I think it was. Used to growl out over Purley when 28 (as was) was in use... Early 80s? Fred Olsen Electra Saturday mornings as well, though they didn't depart via Purley...