Carrier route record
YXSDF→ORD
Republic Airways · Louisville to Chicago
- Flights
- 1,736
- Period
- July 2025 to June 2026
- Share of route
- 62%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Republic Airways.
Republic on SDF to ORD lands a B, 5 points better than the national rate of 77.6%. About one flight in six 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 1,736 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 416 at 77.5% on time.
Set against the rest of the country, Republic's SDF to ORD record is 5 points better than the US average of 77.6%. That gap is worth roughly 49 fewer late arrivals for every thousand flights.
Key figures
On time
82.5%
Arrivals under 15 minutes late, of 1,689 completed flights
Avg delay
67 min
Across delayed arrivals only, not all flights
Cancelled
2.71%
National rate is 1.81%
Whole route
79.0%
Every carrier on SDF to ORD, 2,807 flights
These figures cover 1,736 flights between July 2025 and June 2026. The median arrival is 9 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
Republic against every carrier on SDF to ORD
Republic flew 1,736 of the 2,807 flights on SDF to ORD, most of the route. Its 82.5% on time is 4 points better than the route as a whole, which runs 79.0%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from Republic at 82.5% to United at 50.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Envoy Air arrives on time 77.5% of the time; SkyWest Airlines manages 70.9%. Sample sizes sit next to every figure, because a two-point gap across 645 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airways (this page) | 1,736 | 82.5% | 67 min | 2.71% | B |
| Envoy Air | 416 | 77.5% | 78 min | 1.44% | B |
| SkyWest Airlines | 645 | 70.9% | 96 min | 3.88% | C− |
| American Airlinesthin sample | 3 | 66.7% | 48 min | 0.00% | C+ |
| United Airlinesthin sample | 6 | 50.0% | 54 min | 0.00% | F+ |
SkyWest Airlines cancels 3.9% 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.
Flight by flight
Republic flight numbers on SDF to ORD
Departure window
When Republic runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 18 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am784 flights85.9%
- 8am–11am484 flights83.4%
- 11am–2pm196 flights83.3%
- 2pm–5pm28 flights—
- 5pm–8pm243 flights68.2%
- 8pm–5am1 flights—
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 85.9% of the time, against 68.2% for the evening window. That is 18 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 784 flights scheduled in it.
Across the year
Republic on SDF to ORD through the year
September is the best month on the calendar at 92.8% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. May was the busiest month here, with 206 flights.
Across the week, Thursday is the strongest day at 86.5% on time and Friday the weakest at 77.7%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Republic runs late on this route
One category carries most of the weight here. National Airspace System accounts for 46% of the 20,000 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.
- 46%National Airspace System
- 29%Late-arriving aircraft
- 18%Carrier
- 6%Extreme weather
46% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 9,156 minutes out of 20,000, against a national NAS share of 21%. The split is drawn from 19,843 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 85.9% on time here.
Cancellations run at 2.71%, against 1.81% nationally. That is about one flight in 40 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 costs
6.4% 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.
At 286 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 is a different operation and performs like one: it runs 75.0% on time across 1,733 flights, 8 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 8 points of difference.
The sample behind these figures is 1,736 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 Republic on SDF to ORD
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 92.8% on time and November 74.8%, a swing of 18 points. If the dates move at all, move them out of November before you think about anything else. 1,689 completed flights over 12 months sit behind that.
Related
Where to go next
- SDF to ORD, every carrier
- Republic on ORD to SDF, the return leg
- Envoy Air on SDF to ORD77.5%
- SkyWest Airlines on SDF to ORD70.9%
- Republic Airways network-wide record
- Chicago O'Hare International (ORD) delay statistics
- The US routes with the most cancellations
- 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.