Carrier route record
UADEN→TYS
United Airlines · Denver to Knoxville
- Flights
- 336
- Period
- July 2025 to June 2026
- Share of route
- 35%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to TYS lands a B+, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 336 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on DEN to TYS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
81.0%
Arrivals under 15 minutes late, of 336 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
Whole route
78.0%
Every carrier on DEN to TYS, 967 flights
These figures cover 336 flights between July 2025 and June 2026. The median arrival is 4 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
United against every carrier on DEN to TYS
United flew 336 of the 967 flights on DEN to TYS, about 35% of it. Its 81.0% on time is 3 points better than the route as a whole, which runs 78.0%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from United at 81.0% to Allegiant at 70.8%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page)thin sample | 336 | 81.0% | 48 min | 0.00% | B+ |
| Frontier Airlinesthin sample | 129 | 80.6% | 63 min | 0.00% | B+ |
| SkyWest Airlines | 393 | 76.1% | 64 min | 1.02% | B |
| Southwest Airlinesthin sample | 43 | 74.4% | 42 min | 0.00% | C+ |
| Allegiant Airthin sample | 66 | 70.8% | 174 min | 1.52% | C |
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am207 flights82.6%
- 11am–2pm65 flights84.6%
- 2pm–5pm—
- 5pm–8pm64 flights71.9%
- 8pm–5am—
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 84.6% on time, ahead of 5pm–8pm at 71.9%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 8am–11am window is the busiest, with 207 flights scheduled in it.
Across the year
United on DEN to TYS through the year
August is the worst month at 64.5% on time, 36 points below November, the best at 100.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. May was the busiest month here, with 62 flights.
Across the week, Wednesday is the strongest day at 87.0% on time and Thursday the weakest at 75.5%. 12 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 3,059 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 50%Late-arriving aircraft
- 28%Carrier
- 22%National Airspace System
50% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 3,059 reported delay minutes here, that single category outweighs weather by 50 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 3,059 reported delay minutes.
Cancellations are rare at 0.00%, below the national 1.81% 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 stage length
What a delay here costs
Badly late arrivals are rare here: only 4.5% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,162 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 81.4% on time across 335 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 336 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 United on DEN to TYS
Put together: treat all of this as provisional. 336 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 81.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 336 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to TYS, every carrier
- United on TYS to DEN, the return leg
- Frontier Airlines on DEN to TYS80.6%
- SkyWest Airlines on DEN to TYS76.1%
- United Airlines network-wide record
- Denver International (DEN) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.