Flight number record

YX 4636

Republic Airways · Boston to Indianapolis

Route: BOS → IND
Departs: 10:45
Flights: 268
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s YX 4636, 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 4636 earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 268 flights, with a median arrival 14 minutes early.

Set against the rest of the country, YX 4636's record is 10 points better than the US average of 77.6%. That gap is worth roughly 95 fewer late arrivals for every thousand flights.

On time

87.1%

Arrivals under 15 minutes late, of 264 completed flights

Avg delay

69 min

Across delayed arrivals only, not all flights

Cancelled

1.49%

National rate is 1.81%

1 hour+ late

5.3%

National rate is 8.1%

These figures cover 268 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 4636 flies

YX 4636 flies BOS to IND without a single fixed slot. Its most common scheduled departure was 10:45, used on 37 of 268 flights, with 13:25 (34 flights) and 12:45 (27 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 10:4537 flights13.8%
Departs 13:2534 flights12.7%
Departs 12:4527 flights10.1%

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 10:45 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and YX 4636 runs 3 points better at 87.1%. 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 4636 next to BOS to IND

Every carrier on BOS to IND combined arrived on time 81.6% of the time across 2,017 flights, so YX 4636 is 6 points ahead of it. Republic flew 1,962 flights on the same city pair under all its flight numbers, including this one, and those ran 81.9% on time. Across its whole network Republic Airways managed 78.5%, which this flight beats by 9 points.

YX 4636 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
YX 4636thin sample	268	87.1%	69 min	1.49%	A
All Republic Airways on BOS–IND	1,962	81.9%	68 min	2.24%	B
All carriers on BOS–IND	2,017	81.6%	68 min	2.23%	B
Republic Airways, whole network	361,482	78.5%	72 min	4.08%	B−

Across the year

YX 4636 quarter by quarter

Quarter by quarter YX 4636 held fairly steady: 90.2% in Jul–Sep 2025, 85.7% in Oct–Dec 2025, 85.2% in Jan–Mar 2026 and 85.4% in Apr–Jun 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights90.2%
Oct–Dec 202578 flights85.7%
Jan–Mar 202657 flights85.2%
Apr–Jun 202641 flights85.4%

Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, YX 4636 ranged from 82.1% on Tuesday to 92.3% on Friday. With about 38 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why YX 4636 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 56% of the 2,331 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.

Late-arriving aircraft
56%
Carrier
22%
National Airspace System
15%
Extreme weather
7%

56% 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 2,331 reported delay minutes here, that single category outweighs weather by 8 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 2,331 delay minutes reported on YX 4636.

Cancellations sit at 1.49% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and routes

What a delay on this flight costs

5.3% 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 a little over an hour, which a normal layover absorbs.

The 818 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 five other city pairs in the data, including PIT to PHL (44), ORD to AVL (21) and AVL to ORD (21), but none flew often enough under YX 4636 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BOS to IND only.

One caution: this is a thin sample. 268 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 4636

For a booking, YX 4636 has one of the better records a US domestic flight can show: 87.1% on time and 1.49% cancelled. That is a base rate, not a promise about any single day.

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