About 1 in 6 AA 3421 flights from Champaign arrived 15+ minutes late, diverted or cancelled over the past year (16%); 1.4% were cancelled. The typical flight landed 16 minutes early.
AA 3421: CMI → ORD
Scheduled to leave Champaign at 6:05 a.m. local time, operated by Envoy as MQ 3421. Over the past year it arrived on time 84% of the time (141 flights), in line with other AA flights on the route at that hour (85%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 22 | 77% |
| Tuesday | 14 | — |
| Wednesday | 21 | 90% |
| Thursday | 21 | 81% |
| Friday | 21 | 86% |
| Saturday | 21 | 90% |
| Sunday | 21 | 76% |
Why it was late
All flights CMI → ORD · Connecting off AA 3421? Check the risk
Questions
How often is AA 3421 from CMI to ORD late?
American Airlines 3421 from Champaign/Urbana, IL to Chicago, IL arrived 15 or more minutes late, was diverted or was cancelled on 16% of 141 scheduled flights between September 2025 and August 2026. 1.4% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check American Airlines for today's flight. Method.