Originally Posted by
gregsfortytwo
OP refers to a DTW-SEA flight, not a proper transcon to New York. I know there aren’t any D1 flights to DTW (apart from seasonal Hawaii, although that might be dead again).
AFAIK all continental-48 D1 flights involve one of JFK, BOS, and I think IAD, right? (And then on the other side LAX, SFO, and a very few on SEA.)
DCA-LAX, LAS/SAN also have one daily D1. SEA has at least 1 and sometimes 2 D1 daily.