Route reliability record
ORD→TYS
Chicago to Knoxville
- Flights
- 2,219
- Period
- July 2025 to June 2026
- Distance
- 475 mi
- Carriers
- 5
This route carries a cancellation problem, not just a delay problem: 3.7% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about two flights in three arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 2,219 flights, of which SkyWest Airlines flew 815 at 71.6% on time.
The national on-time rate over the same period is 77.6%, so this route runs 11 points behind the country as a whole. Across a thousand flights that is about 109 extra late arrivals.
Key figures
On time
66.7%
Arrivals under 15 minutes late, of 2,133 completed flights
Avg delay
104 min
Across delayed arrivals only, not all flights
Cancelled
3.74%
National rate is 1.81%
Best carrier
SkyWest
71.6% on time across 815 flights
These figures cover 2,219 flights between July 2025 and June 2026. Beyond the headline rate, 15.3% 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
Which airline is most reliable on ORD to TYS
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 71.6% of the time; PSA Airlines manages 60.2%. Sample sizes sit next to every figure, because a two-point gap across 834 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Airthin sample | 176 | 79.1% | 46 min | 2.27% | B |
| Republic Airwaysthin sample | 78 | 75.6% | 59 min | 0.00% | B+ |
| SkyWest Airlines | 815 | 71.6% | 75 min | 1.84% | C |
| United Airlinesthin sample | 316 | 61.0% | 82 min | 2.53% | D |
| PSA Airlines | 834 | 60.2% | 143 min | 6.71% | D− |
PSA Airlines cancels 6.7% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 25 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am237 flights79.4%
- 8am–11am534 flights73.4%
- 11am–2pm214 flights73.0%
- 2pm–5pm491 flights66.5%
- 5pm–8pm577 flights54.6%
- 8pm–5am166 flights59.4%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 54.6% on time, against 79.4% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 577 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 29 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
January is the weak month at 50.9% on time, against 79.9% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 245 flights.
Across the week, Tuesday is the strongest day at 69.9% on time and Sunday the weakest at 63.3%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 55% of the 74,000 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.
- 55%Late-arriving aircraft
- 25%Carrier
- 12%National Airspace System
- 9%Extreme weather
55% 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 74,000 reported delay minutes here, that single category outweighs weather by 6 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 73,847 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 79.4% on time here.
Cancellations run at 3.74%, against 1.81% nationally. That is about one flight in 25 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 15.3% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 475 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg runs 68.2% on time across 2,220 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 2,219 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking this route
Put together: the delay figures matter less here than the 3.74% cancellation rate. A late arrival costs you close to two hours; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 2,133 completed flights over 12 months sit behind that.
Common questions
ORD to TYS questions
How often is ORD to TYS delayed?
About one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 33.3% of the 2,219 flights in this analysis, against 22.4% nationally. Delayed flights are late by close to two hours on average.
Which airline is most reliable on ORD to TYS?
SkyWest Airlines leads at 71.6% on time across 815 flights. PSA Airlines is at the other end on 60.2%, a gap of 11 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on ORD to TYS?
The 5am–8am departure window is the strongest at 79.4% on time. The 5pm–8pm window is the weakest at 54.6%, 25 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are January delays on ORD to TYS?
January is the weakest month at 50.9% on time, compared with 79.9% in September. Across the year that is 29 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- TYS to ORD — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- Envoy Air on-time record79.1%
- Republic Airways on-time record75.6%
- SkyWest Airlines on-time record71.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. ORD to TYS and TYS to ORD are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.