Originally Posted by
johnnyappleseed
This forum has led me to believe that one of the uses of "United xxx heavy" was when 2 flights with the same number are in the air simultaneously (which apparently is incorrect), so I hadn't considered this. Thanks.
Nope, the "heavy" designation goes to any aircraft over 255,000lbs, or very close to that. In the UA fleet that would be the 767, 777, and 747, although the 757-200 that UA flies comes very close in weight and has the wake of a heavy.