Flight profile · United Airlines
UA661
Newark (EWR) to Chicago (ORD) · scheduled 4:45 PM – 6:34 PM
How UA661 performs
627 operations, September 2024 – August 2026.
Between its first and last recorded date on EWR → ORD, UA661 averaged about 6 operations a week (627 in 705 days, cancelled ones included).
UA661 arrived on time 51.2% of the time, against 73.2% for all EWR → ORD flights, so this departure is 22.0 percentage points worse than the route as a whole. Against United Airlines’ own flights on this route it is 22.5 points worse.
Source: US DOT Bureau of Transportation Statistics · 627 operations, September 2024 – August 2026 · If UA661 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
What stands out
How UA661 compares to other flight numbers, not just to itself.
This flight runs unusually far behind the carrier's own average on this route, worse than 99% of 12,152 comparable flight numbers.
51.2% on time for this specific departure, against 73.7% for the same carrier's other flights on this route.
Source: FlyerIntel analysis of US DOT BTS data · September 2024 – August 2026 · The one thing about this specific departure that ranks most extreme against every other published flight number, out of everything FlyerIntel checks — shown only when something clears a real statistical bar, not for every flight.
Where UA661 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| UA661 | 51.2% | 2.39% | 14 min | 16.7% | 627 |
| United Airlines on EWR → ORD | 73.7% | 2.24% | -4 min | 10.4% | 13,383 |
| All EWR → ORD flights | 73.2% | 2.93% | -5 min | 11.3% | 19,004 |
UA661 cancelled 15 of 627 operations (2.39%), below the 2.93% for EWR → ORD.
16.7% of UA661’s arrivals were an hour or more late, against 11.3% across EWR → ORD, so the long delays are more common on this number than on the route.
Source: FlyerIntel analysis of US DOT BTS data · September 2024 – August 2026
Why UA661 runs late
Where US DOT attributed the delay minutes on this flight.
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for UA661 on EWR → ORD. Only delays of 15 minutes or more are attributed. What the five causes mean
Source: US DOT Bureau of Transportation Statistics · Data covering September 2024 – August 2026
Does a late aircraft delay this flight?
How often the plane that flies UA661 comes in late, and what that does to the departure.
The aircraft flying UA661 came in 15 or more minutes late on 21% of the departures where its previous flight is known. There are not enough departures in both groups to say how the flight left after a late one and after an on-time one.
Matched by tail number to the aircraft’s previous flight into EWR: 427 of 615 departures. Unknown, cancelled or diverted inbounds and gaps over 12 hours are left out.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late |
|---|---|
| UA661 | 21% |
| Network, same turn | 17% |
81 scheduled minutes is enough to clean and board when the aircraft is on time, with little to spare when it is not.
The network row is every flight with a scheduled turn of 60 to 89 minutes. How often UA661’s aircraft landed 15 or more minutes late is higher than the network’s. There are not enough departures in both groups to compare how it left.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2024 – August 2026
From pushback to gate
When it leaves EWR late, does that still matter by the time it reaches ORD?
UA661 pushes back an average of 23.9 minutes late and arrives a further 10.2 minutes behind that. This departure loses ground between the two gates rather than recovering it, so a late pushback here tends to get worse on the way, not better. It spends 27.5 minutes on the taxiways at EWR, 2.3 minutes longer than a typical EWR departure in the same hour.
On arrival at ORD, UA661 spends 29.7 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is 11.7 minutes longer than a typical ORD arrival (18.0 min).
Taxi-out is gate to wheels up and sits inside the scheduled block; the hourly comparison is 26,608 EWR departures. Taxi-in is landing to gate, set against 985,848 arrivals at ORD. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · September 2024 – August 2026
The hour it leaves EWR
UA661 has one departure time, 4:45 PM, so this is what that hour at EWR is worth.
On-time arrival rate. 26,608 departures from EWR are scheduled in the 4 PM–5 PM hour over the period, against 397,593 across the whole day.
UA661 is scheduled out of EWR at 4:45 PM, in the 4 PM–5 PM bank. Departures from EWR in that hour arrive on time 73.4% of the time against 77.5% across the airport’s whole day — the slot alone is worth 4.1 points worse before anything about this particular flight is considered.
Both airport figures cover every destination from EWR, so they describe the slot, not this journey; the route comparison is above. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · September 2024 – August 2026 · Hours below 120 departures are not scored.
Other routes UA661 has flown
Carriers reassign flight numbers. UA661 also served these 25 other city pairs in the period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| SNA→EWR Santa Ana to Newark | February 12, 2026 – August 31, 2026 | 178 | 90.4% |
| ORD→IND Chicago to Indianapolis | August 11–31, 2026 | 21 | — |
| ORD→LAX Chicago to Los Angeles | October 26, 2025 – August 10, 2026 | 199 | 63.6% |
| TPA→EWR Tampa to Newark | May 1, 2025 – January 5, 2026 | 39 | — |
| PIT→ORD Pittsburgh to Chicago | December 2–17, 2025 | 16 | — |
| SEA→EWR Seattle to Newark | October 26–31, 2025 | 6 | — |
| ORD→FAT Chicago to Fresno | September 25, 2025 – October 24, 2025 | 26 | — |
| ORD→DSM Chicago to Des Moines | August 19, 2025 – September 24, 2025 | 37 | — |
| MYR→EWR Myrtle Beach to Newark | August 19, 2025 – September 1, 2025 | 14 | — |
| CLE→IAH Cleveland to Houston | August 1–18, 2025 | 18 | — |
| CLT→EWR Charlotte to Newark | June 26, 2025 – July 31, 2025 | 36 | — |
| PBI→EWR West Palm Beach to Newark | April 1, 2025 – June 25, 2025 | 50 | — |
| ORD→SLC Chicago to Salt Lake City | February 15, 2024 – June 24, 2025 | 409 | 66.0% |
| RSW→EWR Fort Myers to Newark | January 7, 2025 – February 12, 2025 | 37 | — |
| ORD→DEN Chicago to Denver | January 7, 2025 – February 12, 2025 | 36 | — |
| SLC→IAD Salt Lake City to Washington | December 19, 2024 – January 6, 2025 | 17 | — |
| MIA→EWR Miami to Newark | October 27, 2024 – December 2, 2024 | 32 | — |
| ORD→PSP Chicago to Palm Springs | November 30, 2024 – December 1, 2024 | 2 | — |
| TPA→ORD Tampa to Chicago | September 29, 2023 – September 25, 2024 | 204 | 60.9% |
| EWR→TPA Newark to Tampa | September 29, 2023 – February 14, 2024 | 120 | 91.4% |
| TPA→IAH Tampa to Houston | January 9, 2024 – February 14, 2024 | 37 | — |
| ORD→EWR Chicago to Newark | October 29, 2023 – November 27, 2023 | 29 | — |
| ORD→AUS Chicago to Austin | September 29, 2023 | 1 | — |
| EWR→IAH Newark to Houston | September 5–15, 2023 | 11 | — |
| EWR→SAV Newark to Savannah | July 1, 2023 – September 4, 2023 | 65 | — |
The figures above describe only EWR → ORD, the route UA661 flies now.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
94 min late
against a median of 14 min late
UA661 has an average that understates its risk: a typical arrival is 14 min late, but the worst tenth are 80 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 627 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2024 – August 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| UA1525 | United Airlines | 80.4% | 10 min early | 806 |
| UA546 | United Airlines | 63.4% | 3 min late | 633 |
| UA661 this flight | United Airlines | 51.2% | 14 min late | 627 |
| UA254 | United Airlines | 46.9% | 17 min late | 763 |
Among all 4 departures on this route with at least 600 operations, UA661 has the 3rd highest on-time rate, 29.2 points behind the best. Every departure here has at least 600 operations; the other rows are the most punctual on the route, not all of them.
Data and methodology
Calculated by FlyerIntel from 627 records of UA661 operating EWR → ORD, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule; cancelled and diverted flights are reported separately, not in the on-time rate.
Full methodology · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
Analysis last recomputed