Flight number record
UA 478
United Airlines · Billings to Denver
- Route
- BIL → DEN
- Departs
- 14:35
- Flights
- 359
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 478, check with United Airlines.
UA 478 lands a B+, about a point worse than the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 359 flights, with a median arrival 10 minutes early.
Key figures
On time
76.4%
Arrivals under 15 minutes late, of 356 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
8.1%
National rate is 8.3%
These figures cover 359 flights between September 2025 and August 2026. Beyond the headline rate, 8.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 478 flies
UA 478 flies BIL to DEN without a single fixed slot. Its most common scheduled departure was 14:35, used on 100 of 359 flights, with 14:25 (81 flights) and 14:30 (52 flights) next.
- Departs 14:35100 flights27.9%
- Departs 14:2581 flights22.6%
- Departs 14:3052 flights14.5%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 14:35 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and UA 478 runs 5 points better at 76.4%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
UA 478 next to BIL to DEN
Every carrier on BIL to DEN combined arrived on time 82.5% of the time across 1,774 flights, so UA 478 is 6 points behind it. United flew 725 flights on the same city pair under all its flight numbers, including this one, and those ran 84.1% on time. Across its whole network United Airlines managed 78.8%, which this flight trails by 2 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 478thin sample | 359 | 76.4% | 76 min | 0.00% | B+ |
| All United Airlines on BIL–DEN | 725 | 84.1% | 85 min | 0.28% | B+ |
| All carriers on BIL–DEN | 1,774 | 82.5% | 89 min | 0.96% | B+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 478 quarter by quarter
UA 478 did not run the same all year. Its best quarter was Apr–Jun 2026 at 82.2% on time and its weakest Jul–Sep 2026 at 58.9%, a swing of 23 points on roughly 72 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights60.0%
- Oct–Dec 202591 flights81.3%
- Jan–Mar 202690 flights82.0%
- Apr–Jun 202691 flights82.2%
- Jul–Sep 202657 flights58.9%
Scale runs 50% to 90%.
By weekday, UA 478 did best on Sunday at 88.0% on time and worst on Saturday at 68.0%. Each day rests on about 51 flights, so a gap of 20 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 478 runs when it is late
UA 478 often beats the schedule: 150 of 356 completed flights, 42%, arrived 15 minutes or more early. The 84 late arrivals split 27 under half an hour, 28 between 30 and 60 minutes, and 29 an hour or more.
- 15+ min early150 flights42.1%
- Within 15 min122 flights34.3%
- 15–29 min late27 flights7.6%
- 30–59 min late28 flights7.9%
- 1–2 hours late12 flights3.4%
- 2+ hours late17 flights4.8%
Scale runs 0% to 100%.
Share of 356 completed flights by arrival against schedule.
9 of 67 late departures made up the time and arrived on time, 13% of them. In the other direction, 26 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DEN.
The worst days
Worst days for UA 478
The latest arrival of the period was on 23 July 2026, 7 hours 40 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as national airspace system delay.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 23 July 2026 | 7 hours 40 minutes | Late-arriving aircraft |
| 14 August 2026 | 7 hours 1 minute | National Airspace System |
| 6 March 2026 | 5 hours 57 minutes | Late-arriving aircraft |
| 22 July 2026 | 4 hours 35 minutes | National Airspace System |
| 15 August 2026 | 3 hours 53 minutes | National Airspace System |
Delay causes
Why UA 478 runs late
National Airspace System accounts for 46% of the 6,384 delay minutes carriers reported here, and the remaining four split what is left.
- 46%National Airspace System
- 39%Late-arriving aircraft
- 13%Carrier
- 2%Extreme weather
39% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,384 reported delay minutes here, that single category outweighs weather by 16 to one. The split is drawn from 6,384 delay minutes reported on UA 478.
Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
8.1% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
The same number turns up on three other city pairs in the data, including DEN to LAS (36), ORD to CLE (1) and ORD to MSN (1), but none flew often enough under UA 478 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BIL to DEN only.
One caution: this is a thin sample. 359 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking UA 478
For a booking, UA 478 is one of the weaker ways to fly BIL to DEN: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.
Related
Where to go next
- BIL to DEN, every carrier and departure
- DEN to BIL, the return direction
- United Airlines 372 on the same route91.8%
- SkyWest Airlines 4758 on the same route71.4%
- Denver International (DEN) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means United Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.