AA were flip flopping between between B752 and B763 last week, couldn't figure out why initially. DL were also switching between B763 and B764, any ideas which of those is scheduled for the summer?
DL is 763 for most of the summer as aircraft route ATL-DUB-JFK and JFK-DUB-ATL. 764 scheduled for winter and was to increase capacity to JFK after they decided to close ATL in November/December. If I am correct it was a very short notice decision something about their B744's being withdrawn earlier than planned. 764 currently showing for this coming winter again.
AA 763 was for a brief period during peak season.