Flight number record

YX 5721

Republic Airways · Boston to New York

Route: BOS → LGA
Departs: 17:00
Flights: 323
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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 sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 10 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 323 flights, with a median arrival 8 minutes early.

The national on-time rate over the same period is 77.6%, so YX 5721 runs 10 points behind the country as a whole. Across a thousand flights that is about 95 extra late arrivals.

On time

68.1%

Arrivals under 15 minutes late, of 295 completed flights

Avg delay

72 min

Across delayed arrivals only, not all flights

Cancelled

8.67%

National rate is 1.81%

1 hour+ late

13.9%

National rate is 8.1%

These figures cover 323 flights between July 2025 and June 2026. Beyond the headline rate, 13.9% 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.

Schedule

When YX 5721 flies

YX 5721 is scheduled to leave Boston (BOS) at 17:00 local time and reach New York (LGA) at 18:33. That slot held for 316 of the 323 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.

Departs 17:00316 flights97.8%

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 17:00 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and YX 5721 runs level with that at 68.1%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

YX 5721 next to BOS to LGA

Every carrier on BOS to LGA combined arrived on time 77.7% of the time across 7,251 flights, so YX 5721 is 10 points behind it. Republic flew 6,708 flights on the same city pair under all its flight numbers, including this one, and those ran 76.6% on time. Across its whole network Republic Airways managed 78.5%, which this flight trails by 10 points.

YX 5721 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
YX 5721thin sample	323	68.1%	72 min	8.67%	C−
All Republic Airways on BOS–LGA	6,708	76.6%	75 min	5.81%	B−
All carriers on BOS–LGA	7,251	77.7%	77 min	5.70%	B−
Republic Airways, whole network	361,482	78.5%	72 min	4.08%	B−

Across the year

YX 5721 quarter by quarter

Quarter by quarter YX 5721 held fairly steady: 69.5% in Jul–Sep 2025, 64.3% in Oct–Dec 2025, 65.2% in Jan–Mar 2026 and 72.3% in Apr–Jun 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights69.5%
Oct–Dec 202589 flights64.3%
Jan–Mar 202654 flights65.2%
Apr–Jun 202688 flights72.3%

Scale runs 55% to 80%. Rows with fewer than 30 flights show a dash.

By weekday, YX 5721 did best on Saturday at 90.5% on time and worst on Sunday at 51.2%. Each day rests on about 46 flights, so a gap of 39 points is worth noticing but could still narrow in another year.

Delay causes

Why YX 5721 runs late

One category carries most of the weight here. National Airspace System accounts for 43% of the 6,732 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.

National Airspace System
43%
Late-arriving aircraft
30%
Carrier
27%

43% 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 2,906 minutes out of 6,732, against a national NAS share of 21%. The split is drawn from 6,732 delay minutes reported on YX 5721.

Cancellations run at 8.67%, against 1.81% nationally. That is about one flight in twelve 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 13.9% 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.

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. 323 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: 8.67% of its 323 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.

Where to go next

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.

Key figures