Carrier route record

F9DEN→TYS

Frontier Airlines · Denver to Knoxville

Flights: 129
Period: July 2025 to June 2026
Share of route: 13%
Carriers: 5

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.

Frontier 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 about an hour on average. That is a workable record, not a spotless one. That rests on 129 flights, with a median arrival 9 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Frontier on DEN to TYS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

80.6%

Arrivals under 15 minutes late, of 129 completed flights

Avg delay

63 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 129 flights between July 2025 and June 2026. Beyond the headline rate, 8.5% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Frontier against every carrier on DEN to TYS

Frontier flew 129 of the 967 flights on DEN to TYS, about 13% of it. Its 80.6% on time is 3 points better than the route as a whole, which runs 78.0%. Ranked by on-time rate it is number two 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.

On-time performance by carrier on DEN to TYS
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlinesthin sample	336	81.0%	48 min	0.00%	B+
Frontier Airlines (this page)thin 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 Frontier runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 14 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–8am1 flights—
8am–11am32 flights84.4%
11am–2pm42 flights71.4%
2pm–5pm54 flights85.2%
5pm–8pm—
8pm–5am—

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 71.4% on time against 85.2% for 2pm–5pm. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 2pm–5pm window is the busiest, with 54 flights scheduled in it.

Across the year

Frontier on DEN to TYS through the year

Jul–Sep 202532 flights71.9%
Oct–Dec 202541 flights80.5%
Jan–Mar 202627 flights—
Apr–Jun 202629 flights—

Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 80.6% on time across 129 flights.

Split by quarter, Frontier on DEN to TYS logged 32 flights in Jul–Sep 2025, 41 flights in Oct–Dec 2025, 27 flights in Jan–Mar 2026 and 29 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 80.6% annual figure is the one to use.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 1,565 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.

Late-arriving aircraft
45%
Carrier
33%
National Airspace System
19%
Extreme weather
3%

45% 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 1,565 reported delay minutes here, that single category outweighs weather by 17 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 1,565 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

8.5% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

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 is a different operation and performs like one: it runs 75.2% on time across 129 flights, 5 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.

One caution: this is a thin sample. 129 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 Frontier on DEN to TYS

Put together: treat all of this as provisional. 129 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 80.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 129 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures