Originally Posted by mnbp

http://flightaware.com/live/flight/DAL617

According to the above list, on 15AUG, DL 617 PDX-NRT canceled, and the continuation 16AUG DL 617 NRT-PEK operated with a 757 instead of a 763. The 744 on 17AUG's DL 617 NRT-PEK could have been to deal with the overflow from the prior day's NRT-PEK-NRT flights being operated with a 757 instead of the usual 763.