Flight profile · United Airlines
UA2278
San Francisco (SFO) to Chicago (ORD) · scheduled 10:50 PM – 4:58 AM
How UA2278 performs
139 operations, 2026-02-12 to 2026-06-30.
UA2278 arrived on time 85.3% of the time, against 79.1% for all SFO → ORD flights — this specific departure is 6.1 percentage points better than the route as a whole. Against United Airlines’s own flights on this route it is 4.6 points better.
Source: US DOT Bureau of Transportation Statistics · 139 operations between 2026-02-12 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| UA2278 | 85.3% | 2.16% | -15 min | 6.6% | 139 |
| United Airlines on SFO → ORD | 80.6% | 1.00% | -8 min | 6.4% | 10,627 |
| All SFO → ORD flights | 79.1% | 1.09% | -8 min | 7.0% | 15,597 |
Source: FlyerIntel analysis of US DOT BTS data · 2026-02-12 to 2026-06-30
Other routes UA2278 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| SAN→SFO San Diego to San Francisco | 2026-02-12 – 2026-06-29 | 111 | 40.9% |
| LGA→ORD New York to Chicago | 2025-10-26 – 2026-02-11 | 101 | 59.0% |
| ORD→SEA Chicago to Seattle | 2023-10-29 – 2025-12-01 | 646 | 80.1% |
| TPA→ORD Tampa to Chicago | 2025-08-01 – 2025-08-18 | 18 | — |
| PIT→ORD Pittsburgh to Chicago | 2025-05-22 – 2025-06-25 | 35 | — |
| ONT→DEN Ontario to Denver | 2025-01-07 – 2025-02-12 | 37 | — |
| ORD→CID Chicago to Cedar Rapids | 2024-12-03 – 2024-12-18 | 16 | — |
| MYR→ORD Myrtle Beach to Chicago | 2024-05-23 – 2024-08-18 | 80 | — |
| SEA→SFO Seattle to San Francisco | 2023-12-21 – 2024-07-31 | 43 | — |
| RDU→IAH Raleigh–Durham to Houston | 2024-01-09 – 2024-02-14 | 37 | — |
| SAV→ORD Savannah to Chicago | 2023-12-23 – 2024-01-08 | 5 | — |
| SEA→EWR Seattle to Newark | 2023-12-01 – 2023-12-20 | 20 | — |
| AUS→ORD Austin to Chicago | 2023-09-05 – 2023-11-27 | 77 | — |
| ORD→SFO Chicago to San Francisco | 2023-09-05 – 2023-10-28 | 54 | — |
| EWR→DEN Newark to Denver | 2023-08-01 – 2023-09-04 | 35 | — |
| EWR→SAN Newark to San Diego | 2023-07-01 – 2023-07-31 | 31 | — |
Because the same number has served different journeys, the statistics above describe only the route UA2278 currently operates. Blending them would produce an average of two different flights.
Why UA2278 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding, fuelling — within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
Share of the delay minutes US DOT attributed to each cause for UA2278 on SFO → ORD. A single late flight can carry more than one cause, and only delays of fifteen minutes or more are attributed at all.
Other departures on SFO → ORD
Same airports, same journey — and not the same odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| AA2614 | American Airlines | 91.6% | 16 min early | 1,083 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 139 records of UA2278 operating SFO → 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 excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
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