UA3520 ChicagoORD · 06:56 LouisvilleSDF · 09:38
UA3520 by United Airlines flies from Chicago (ORD) to Louisville (SDF) for the Tue, Aug 18 departure.
arrived at SDF · 41 min early
Where the minutes go
last 7 operations · gate push → arrivalThe bar is how late it left the gate; the ring is where it actually arrived. Board clocks, not estimates.
The last 30 days
arrival outcome per operationmedian arrival −27 min · 0 cancelled · 7 operations tracked
The route today
live boardsWeather lens
Delay & cancellation outlook for this flight
Measured, 90-day sampleConditions 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.
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 UA3520 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 UA3520 actually runs
Pro Flight Search has tracked every published board update for UA3520 across the ORD and SDF boards: schedule changes, gate pushes and actual clocks. Usually lands ~25 min early. Based on 7 confirmed landings · 7/7 within 15 min of schedule. Pushes back late but makes up time in the air.
The verdict above is that record speaking, so it reflects how UA3520 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: N732YX, N770YX, N745YX, N781YX.
Board clocks recorded as ORD and SDF published them.
Planning around UA3520? 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 — UA3520 Chicago to Louisville on-time performance, measured from the ORD and SDF airport boards.
https://proflightsearch.com/flight/UA3520
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