United Airlines operates flight UA399 between Seattle (SEA) and Denver (DEN). This route is typically operated by a 737-900. Based on United Airlines' current Starlink rollout — 665 of 1,575 aircraft equipped (42% of the fleet) — whether this specific flight is equipped depends on the aircraft assigned on the day.
No flights on this route have been observed, and the scheduled aircraft type (B739) is not a reliable guide to the aircraft used, so no rating is shown.
Equipped
Fleet Size
Coverage
The aircraft on this route have not been checked for Starlink. This is not the same as confirming they don't have it.
The aircraft on this route have not been checked for Starlink. This is not the same as confirming they don't have it.
No spam. One email when coverage on SEA→DEN updates.
B739
Based on historical aircraft assignments for this day of the week. Actual aircraft may differ.
The aircraft on this route have not been checked for Starlink. This is not the same as confirming they don't have it — check back as more aircraft are confirmed.
UA399 is used on more than one route, and the aircraft assigned isn't always the same. The score above reflects the best-equipped version, so your flight may differ.
Aircraft recently seen operating this flight
Check the Starlink probability on other United Airlines routes.
We don't yet have enough data to give a confident Starlink prediction for flight UA399. United Airlines is actively rolling out Starlink across its fleet — see the United Airlines page for fleet-wide coverage.
United Airlines uses Starlink satellite WiFi on equipped aircraft. Flight UA399 operates SEA to DEN. We track United Airlines' fleet rollout and confirmed tail numbers to estimate coverage as data accumulates.
The most reliable method is to check your specific tail number after check-in — your boarding pass or the United Airlines app may show the aircraft registration. You can then search that tail number on StarlinkFlights.com.
The aircraft that operate UA399 have not been checked for Starlink, so no confident score can be produced yet. This is not the same as confirming they don't have it — check back as more aircraft are confirmed.
No prediction can guarantee a specific aircraft. Airlines perform last-minute equipment swaps for maintenance, operational needs, or schedule changes — meaning a Starlink-equipped tail can be replaced by a non-equipped one on the day. A score of 80% or above means historical data strongly favours Starlink on this flight, but it is not a guarantee. For the most reliable information, check the airline's gate display or app on the day of departure.
