Flight number record
YX 5721
Republic Airways · Boston to New York
- Route
- BOS → LGA
- Departs
- 17:00
- Flights
- 314
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s YX 5721, 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 5721 draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 314 flights, with a median arrival 6 minutes early.
The national on-time rate over the same period is 77.3%, so YX 5721 runs 10 points behind the country as a whole. Across a thousand flights that is about 102 extra late arrivals.
Key figures
On time
67.1%
Arrivals under 15 minutes late, of 283 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
9.87%
National rate is 1.89%
1 hour+ late
13.4%
National rate is 8.3%
These figures cover 314 flights between September 2025 and August 2026. Beyond the headline rate, 13.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When YX 5721 flies
YX 5721 is scheduled to leave Boston (BOS) at 17:00 local time and reach New York (LGA) at 18:30. That slot held for 307 of the 314 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.
- Departs 17:00307 flights97.8%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 17:00 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and YX 5721 runs level with that at 67.1%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
YX 5721 next to BOS to LGA
Every carrier on BOS to LGA combined arrived on time 76.2% of the time across 7,442 flights, so YX 5721 is 9 points behind it. Republic flew 6,971 flights on the same city pair under all its flight numbers, including this one, and those ran 75.2% on time. Across its whole network Republic Airways managed 78.1%, which this flight trails by 11 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| YX 5721thin sample | 314 | 67.1% | 75 min | 9.87% | C− |
| All Republic Airways on BOS–LGA | 6,971 | 75.2% | 77 min | 6.50% | B− |
| All carriers on BOS–LGA | 7,442 | 76.2% | 78 min | 6.40% | B− |
| Republic Airways, whole network | 364,452 | 78.1% | 74 min | 4.55% | B− |
Across the year
YX 5721 quarter by quarter
Quarter by quarter YX 5721 held fairly steady: 64.3% in Oct–Dec 2025, 65.2% in Jan–Mar 2026, 72.3% in Apr–Jun 2026 and 62.8% in Jul–Sep 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights—
- Oct–Dec 202589 flights64.3%
- Jan–Mar 202654 flights65.2%
- Apr–Jun 202688 flights72.3%
- Jul–Sep 202653 flights62.8%
Scale runs 55% to 80%. Rows with fewer than 30 flights show a dash.
By weekday, YX 5721 did best on Saturday at 87.9% on time and worst on Sunday at 52.3%. Each day rests on about 45 flights, so a gap of 36 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late YX 5721 runs when it is late
YX 5721 often beats the schedule: 89 of 283 completed flights, 31%, arrived 15 minutes or more early. The 93 late arrivals split 23 under half an hour, 32 between 30 and 60 minutes, and 38 an hour or more.
- 15+ min early89 flights31.4%
- Within 15 min101 flights35.7%
- 15–29 min late23 flights8.1%
- 30–59 min late32 flights11.3%
- 1–2 hours late25 flights8.8%
- 2+ hours late13 flights4.6%
Scale runs 0% to 100%.
Share of 283 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 95 departures that left 15 minutes late or more, only 10 made it up before arrival. 8 flights left on time and still arrived late.
The worst days
Worst days for YX 5721
The latest arrival of the period was on 6 July 2026, 13 hours 39 minutes behind schedule; most of its delay minutes were filed as extreme weather. The five worst days are spread across July, January, February and March, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 July 2026 | 13 hours 39 minutes | Extreme weather |
| 30 January 2026 | 7 hours 17 minutes | Carrier |
| 7 February 2026 | 3 hours 39 minutes | Late-arriving aircraft |
| 15 July 2026 | 2 hours 50 minutes | National Airspace System |
| 12 March 2026 | 2 hours 43 minutes | Late-arriving aircraft |
Delay causes
Why YX 5721 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,011 reported delay minutes.
- 34%National Airspace System
- 33%Late-arriving aircraft
- 26%Carrier
- 7%Extreme weather
34% 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 2,358 minutes out of 7,011, against a national NAS share of 21%. The split is drawn from 7,011 delay minutes reported on YX 5721.
Cancellations run at 9.87%, against 1.89% nationally. That is about one flight in ten 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 routes
What a delay on this flight costs
13.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The same number turns up on one other city pair in the data, including IND to BOS (5), but none flew often enough under YX 5721 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BOS to LGA only.
One caution: this is a thin sample. 314 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 5721
For a booking, the cancellation rate is the figure to plan around on YX 5721: 9.87% of its 314 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- BOS to LGA, every carrier and departure
- LGA to BOS, the return direction
- Republic Airways 5736 on the same route73.5%
- Republic Airways 5716 on the same route61.4%
- Republic Airways 5744 on the same route85.8%
- Republic Airways 5831 on the same route62.2%
- Republic Airways 5730 on the same route77.1%
- Republic Airways 5732 on the same route86.1%
- Boston Logan International (BOS) delay statistics
- 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
- Why the first flight of the morning is statistically safest
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.