Flight number record
YX 5643
Republic Airways · New York to Louisville
- Route
- LGA → SDF
- Departs
- 08:30
- Flights
- 264
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s YX 5643, check with Republic Airways. Republic Airways flies under contract for larger airlines, so a ticket for this flight may show a different airline code and number.
YX 5643 earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 40 minutes. That rests on 264 flights, with a median arrival 14 minutes early.
Set against the rest of the country, YX 5643's record is 9 points better than the US average of 77.6%. That gap is worth roughly 89 fewer late arrivals for every thousand flights.
Key figures
On time
86.5%
Arrivals under 15 minutes late, of 260 completed flights
Avg delay
40 min
Across delayed arrivals only, not all flights
Cancelled
1.52%
National rate is 1.81%
1 hour+ late
2.7%
National rate is 8.1%
These figures cover 264 flights between July 2025 and June 2026. The median arrival is 14 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.
Schedule
When YX 5643 flies
YX 5643 flies LGA to SDF without a single fixed slot. Its most common scheduled departure was 08:30, used on 37 of 264 flights, with 09:00 (31 flights) and 09:11 (30 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 08:3037 flights14.0%
- Departs 09:0031 flights11.7%
- Departs 09:1130 flights11.4%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 08:30 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and YX 5643 runs 2 points better at 86.5%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
YX 5643 next to LGA to SDF
Every carrier on LGA to SDF combined arrived on time 79.8% of the time across 1,062 flights, so YX 5643 is 7 points ahead of it. Republic flew 1,026 flights on the same city pair under all its flight numbers, including this one, and those ran 79.5% on time. Across its whole network Republic Airways managed 78.5%, which this flight beats by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| YX 5643thin sample | 264 | 86.5% | 40 min | 1.52% | A |
| All Republic Airways on LGA–SDF | 1,026 | 79.5% | 73 min | 3.61% | B− |
| All carriers on LGA–SDF | 1,062 | 79.8% | 75 min | 3.58% | B− |
| Republic Airways, whole network | 361,482 | 78.5% | 72 min | 4.08% | B− |
Across the year
YX 5643 quarter by quarter
YX 5643 did not run the same all year. Its best quarter was Jul–Sep 2025 at 93.1% on time and its weakest Oct–Dec 2025 at 78.0%, a swing of 15 points on roughly 66 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 202587 flights93.1%
- Oct–Dec 202551 flights78.0%
- Jan–Mar 202636 flights84.8%
- Apr–Jun 202690 flights85.6%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, YX 5643 did best on Wednesday at 94.4% on time and worst on Friday at 81.1%. Each day rests on about 38 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Delay causes
Why YX 5643 runs late
One category carries most of the weight here. Carrier accounts for 44% of the 1,384 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.
- 44%Carrier
- 28%National Airspace System
- 19%Late-arriving aircraft
- 9%Extreme weather
The largest share of delay minutes, 44%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 605 of the 1,384 delay minutes reported here. The split is drawn from 1,384 delay minutes reported on YX 5643.
Cancellations sit at 1.52% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 2.7% 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 659 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 same number turns up on two other city pairs in the data, including SDF to LGA (235) and SDF to BOS (6), but none flew often enough under YX 5643 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to LGA to SDF only.
One caution: this is a thin sample. 264 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 YX 5643
For a booking, read YX 5643 as 86.5% on time with 1.52% cancelled over 264 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- LGA to SDF, every carrier and departure
- SDF to LGA, the return direction
- LaGuardia (LGA) delay statistics
- Republic Airways on-time record
- Every Republic Airways flight number with a record
- The most and least reliable flight numbers in the US
- Worst months to fly in the US, ranked by the data
A flight number here means Republic Airways’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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.