Forgive me if this has been raised before, but I'm confused as to why for example A6-EBA, which is a 777-300ER is designated as 773, whereas A6-ECY, which is also a 777-300ER, is designated as a 77W.
Is there some significant difference between the two? Both I believe are 2-class aircraft, so I'm puzzled and would appreciate if some of you EK experts could explain.