I was always under the impression that HEAVY meant over 300,000 Lbs. Also learned yaers ago that HEAVY was added to the 757 family due to said wake turbulence generated. Heavies other than the 757 family are commercial aviation wise are the 747 and 767 families,A300,A310,A330,A340 families,DC-8,DC-10,MD11 planes,L-1011(tristars) miss those immensely personally and the soon to grace us the heavy of all heavies the A-380 and I dont know about the 787 dreamliner if that is going to be classified as a heavy if someone can advise of such