The only scheduled YLW → SEA departure in the next 48 hours is on a Starlink-equipped aircraft.
Counted from live tail assignments over the next 48 hours. A route with no equipped departures today can still get one — assignments publish about two days before departure.
No flight numbers recorded on this route yet. The route cache fills in as departures are observed.
Want the reverse leg? SEA to YLW, or compare a full itinerary.