Originally Posted by
joejones
Yes, but an immediate turn-around from ORD would get into HND after 10 PM, which is bad for connections and ground transportation, especially if there's a delay. ANA has an evening flight from ORD that gets into HND around 9 PM, but they have several flights to Asia leaving around midnight while JAL only has BKK and SIN.
Also, there are slot restrictions at HND and it's easier to get slots between midnight and 6 AM. JAL may well want to use a precious daytime/evening slot for a different purpose.
They also have SGN as a late night departure from Haneda, the SGN flights always seem to draw a lot of US connections.
HND ORD HND is already assigned day time slots. As part of the last allocation. So by moving it out of the slot restrictions they have half a daytime slot, so they could launch a late night departure day time return.