UA3821 SeattleSEA SeattleBFI
UA3821 by United Airlines flies from Seattle (SEA) to Seattle (BFI).
scheduled from SEA
The route today
live boardsWhen it flies
scheduled departuresEach mark is a scheduled departure at its origin-local time. Today is highlighted.
How UA3821 actually runs
Pro Flight Search has tracked every published board update for UA3821 across the SEA and BFI boards: schedule changes, gate pushes and actual clocks. Combined risk score: 33.0/100. Based on airport operations, weather, and cached board history at SEA and BFI.
The verdict above is that record speaking, so it reflects how UA3821 operates rather than what the timetable promises. Numbers refresh as new flights operate.
How this operation is measured
Board log
scheduled → actual, per operationBoard clocks recorded as SEA and BFI published them.
Planning around UA3821? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
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Pro Flight Search — UA3821 Seattle to Seattle on-time performance, measured from the SEA and BFI airport boards.
https://proflightsearch.com/flight/UA3821
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