UA3551 ChicagoORD · 21:20 LouisvilleSDF · 23:56
UA3551 by United Airlines flies from Chicago (ORD) to Louisville (SDF) for the Sun, Sep 13 departure.
departs ORD · on schedule
board checked 35m ago · checking again in 45s
Where the minutes go
last 4 operations · gate push → arrivalThe bar is how late it left the gate; the ring is where it actually arrived. Board clocks, not estimates.
The route today
live boardsWeather lens
Delay & cancellation outlook for this flight
Early read, sample still buildingConditions at ORD and SDF are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. For this route and airline, under conditions like today's, over the last 90 days. This route's tracked sample is still thin — treat these as an early read, not a precise forecast.
Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →
When it flies
scheduled departuresEach mark is a scheduled departure at its origin-local time. Today is highlighted.
Other Chicago to Louisville flights today
same route · United AirlinesIf UA3551 is cancelled, these are the other United Airlines nonstop flights from Chicago to Louisville on the same day, with scheduled departure times in ORD local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →
How UA3551 actually runs
Pro Flight Search has tracked every published board update for UA3551 across the ORD and SDF boards: schedule changes, gate pushes and actual clocks. Early read — pattern not clear yet. Only 3 completed legs so far: landed -9 min. Not enough to call it.
The verdict above is that record speaking, so it reflects how UA3551 operates rather than what the timetable promises. Numbers refresh as new flights operate.
How this operation is measured
Board log
scheduled → actual, per operationAircraft
Recent tails: N784YX, N756YX.
Board clocks recorded as ORD and SDF published them.
Planning around UA3551? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.
Pro Flight Search — UA3551 Chicago to Louisville on-time performance, measured from the ORD and SDF airport boards.
https://proflightsearch.com/flight/UA3551
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