Flight profile · United Airlines
UA636
Chicago (ORD) to Burlington (BTV) · scheduled 6:20 PM – 9:42 PM
How UA636 performs
297 operations, 2025-08-19 to 2026-06-30.
UA636 arrived on time 64.3% of the time, against 74.5% for all ORD → BTV flights — this specific departure is 10.2 percentage points worse than the route as a whole. Against United Airlines’s own flights on this route it is 11.3 points worse.
Source: US DOT Bureau of Transportation Statistics · 297 operations between 2025-08-19 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| UA636 | 64.3% | 0.67% | 5 min | 10.9% | 297 |
| United Airlines on ORD → BTV | 75.6% | 0.59% | -2 min | 8.5% | 1,866 |
| All ORD → BTV flights | 74.5% | 1.19% | -3 min | 9.2% | 3,206 |
Source: FlyerIntel analysis of US DOT BTS data · 2025-08-19 to 2026-06-30
Other routes UA636 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 |
|---|---|---|---|
| MSO→ORD Missoula to Chicago | 2026-05-21 – 2026-06-30 | 41 | — |
| ORD→EWR Chicago to Newark | 2026-05-23 – 2026-05-30 | 2 | — |
| HDN→ORD Hayden to Chicago | 2026-01-06 – 2026-04-05 | 90 | 71.6% |
| PNS→ORD Pensacola to Chicago | 2025-09-25 – 2026-01-05 | 66 | — |
| ORD→SFO Chicago to San Francisco | 2025-12-02 – 2025-12-17 | 16 | — |
| TUS→ORD Tucson to Chicago | 2025-09-02 – 2025-09-24 | 23 | — |
| IAH→SAT Houston to San Antonio | 2025-05-22 – 2025-08-18 | 82 | — |
| PHX→IAH Phoenix to Houston | 2025-06-26 – 2025-08-18 | 54 | — |
| IAH→LGA Houston to New York | 2025-07-17 – 2025-07-17 | 1 | — |
| MSP→IAH Minneapolis to Houston | 2025-05-22 – 2025-06-25 | 29 | — |
| IAD→LAS Washington to Las Vegas | 2025-01-07 – 2025-05-21 | 135 | 82.2% |
| LAX→CLE Los Angeles to Cleveland | 2024-09-26 – 2025-01-06 | 53 | — |
| IAD→SFO Washington to San Francisco | 2024-12-03 – 2024-12-18 | 16 | — |
| ORD→LAX Chicago to Los Angeles | 2024-09-26 – 2024-10-26 | 31 | — |
| CHS→IAH Charleston to Houston | 2024-06-28 – 2024-09-24 | 84 | — |
| MFR→SFO Medford to San Francisco | 2024-06-27 – 2024-06-27 | 1 | — |
| CMH→EWR Columbus to Newark | 2024-05-23 – 2024-06-26 | 25 | — |
| AUS→SFO Austin to San Francisco | 2024-05-02 – 2024-05-22 | 20 | — |
| EWR→IAH Newark to Houston | 2024-05-05 – 2024-05-05 | 1 | — |
| JAX→IAH Jacksonville to Houston | 2024-02-15 – 2024-03-31 | 42 | — |
| RSW→DEN Fort Myers to Denver | 2024-03-09 – 2024-03-30 | 4 | — |
| FLL→DEN Fort Lauderdale to Denver | 2024-01-09 – 2024-02-14 | 37 | — |
| BTV→IAD Burlington to Washington | 2023-07-03 – 2024-01-08 | 101 | 69.0% |
| IAD→SMF Washington to Sacramento | 2023-12-21 – 2024-01-08 | 9 | — |
| SFO→AUS San Francisco to Austin | 2024-01-06 – 2024-01-06 | 1 | — |
| GRR→ORD Grand Rapids to Chicago | 2023-10-30 – 2023-12-20 | 44 | — |
| ORD→CVG Chicago to Cincinnati / Covington | 2023-11-28 – 2023-12-20 | 20 | — |
| RDU→ORD Raleigh–Durham to Chicago | 2023-12-02 – 2023-12-16 | 3 | — |
| RNO→ORD Reno to Chicago | 2023-09-09 – 2023-09-24 | 6 | — |
| ORD→SYR Chicago to Syracuse | 2023-07-01 – 2023-09-03 | 29 | — |
Because the same number has served different journeys, the statistics above describe only the route UA636 currently operates. Blending them would produce an average of two different flights.
Why UA636 runs late
Where US DOT attributed the delay minutes on this flight.
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding, fuelling — within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for UA636 on ORD → BTV. 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 ORD → BTV
Same airports, same journey — and not the same odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| UA786 | United Airlines | 81.6% | 7 min early | 707 |
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 297 records of UA636 operating ORD → BTV, 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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