Flight profile · Republic Airways
YX5631
Indianapolis (IND) to Boston (BOS) · scheduled 6:00 AM – 8:35 AM
How YX5631 performs
725 operations, June 2024 – July 2026.
YX5631 arrived on time 93.7% of the time, against 81.7% for all IND → BOS flights, so this departure is 12.0 percentage points better than the route as a whole. Against Republic Airways’ own flights on this route it is 11.8 points better.
Source: US DOT Bureau of Transportation Statistics · 725 operations, June 2024 – July 2026 · If YX5631 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
What stands out
How YX5631 compares to other flight numbers, not just to itself.
This flight runs unusually far ahead of the carrier's own average on this route, better than 95% of 11,589 comparable flight numbers.
93.7% on time for this specific departure, against 81.9% for the same carrier's other flights on this route.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026 · The one thing about this specific departure that ranks most extreme against every other published flight number, out of everything FlyerIntel checks — shown only when something clears a real statistical bar, not for every flight.
Where YX5631 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| YX5631 | 93.7% | 1.10% | -16 min | 1.1% | 725 |
| Republic Airways on IND → BOS | 81.9% | 1.63% | -10 min | 7.4% | 5,891 |
| All IND → BOS flights | 81.7% | 1.62% | -10 min | 7.5% | 6,127 |
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
Why YX5631 runs late
Where US DOT attributed the delay minutes on this flight.
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for YX5631 on IND → BOS. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies YX5631 comes in late, and what that does to the departure.
YX5631 is usually the aircraft’s first flight of the day: the schedule gives it a median of 9.6 hours on the ground at IND, so its “inbound” is mostly the aircraft’s arrival the evening before.
When the aircraft came in 15 or more minutes late, YX5631 pushed back an average of 3 minutes early; when it came in on time or early, an average of 5 minutes early.
Each departure is matched to the flight the same aircraft flew into IND just before it, using the tail number in the DOT file, 580 of 717 departures in all. A departure is left out when that flight is unknown, was cancelled or diverted, or the aircraft had sat for more than 12 hours. A flight the airline cancelled never left and is not in the count, and one flown by a substitute aircraft is matched to the aircraft that flew it, not to the one first planned.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late | Left 15+ late after a late inbound | Left 15+ late after an on-time inbound |
|---|---|---|---|
| YX5631 | 28% | 3% | 4% |
| Network, same turn | 29% | 12% | 9% |
A night on the ground absorbs most of a late arrival, so a late inbound matters far less on a turn this long than on a same-day one.
The network row is every flight with a scheduled turn of 6 hours or more, usually overnight. How often YX5631’s aircraft landed 15 or more minutes late is about the same as the network’s and, once the aircraft was late, how often YX5631 left 15 or more minutes late is lower than the network’s.
More: Which Flight Numbers Pay for a Late Aircraft lists the flight numbers that pass a late aircraft on.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – July 2026
From pushback to gate
When it leaves IND late, does that still matter by the time it reaches BOS?
YX5631 pushes back an average of 3.9 minutes early and reaches the gate at BOS an average of 12.0 minutes early. The 8.1 minutes between those two figures are slack the published schedule already carries, which is why a late pushback on this flight does not reliably become a late arrival. Its 16.4 minutes on the taxiways at IND is about what any departure from the airport in that hour spends.
On arrival at BOS, YX5631 spends 12.6 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is 3.7 minutes longer than a typical BOS arrival (9.0 min).
Departure delay is averaged over every pushback and arrival delay over every completed arrival, so the two counts differ by the flights that never reached BOS. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 16,451 departures from IND scheduled in the clock hour YX5631 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at BOS (440,886 flights), not just YX5631’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
The hour it leaves IND
Part of any flight’s record belongs to the clock rather than to the flight. YX5631 has one departure time, so this is what that time is worth.
On-time arrival rate. 16,451 departures from IND are scheduled in the 6 AM–7 AM hour over the period, against 147,128 across the whole day.
YX5631 is scheduled out of IND at 6:00 AM, in the 6 AM–7 AM bank. Departures from IND in that hour arrive on time 90.9% of the time against 81.9% across the airport’s whole day — the slot alone is worth 9.0 points better before anything about this particular flight is considered.
The two airport figures cover every departure from IND to every destination, so they describe the slot rather than this journey — the like-for-like comparison against the route is above. Hours are scheduled local, and a number whose schedule moved between banks inside the period has no single hour and is not described here at all. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026 · Hours below 120 departures are not scored.
Other routes YX5631 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| LGA→BNA New York to Nashville | September 14, 2024 | 1 | — |
| BOS→CLT Boston to Charlotte | January 8, 2024 – June 6, 2024 | 78 | — |
| CLT→BOS Charlotte to Boston | May 7, 2024 – June 6, 2024 | 30 | — |
| LGA→HHH New York to Hilton Head Island | April 22, 2024 – May 6, 2024 | 15 | — |
| MCI→BOS Kansas City to Boston | March 10, 2024 – April 8, 2024 | 26 | — |
| LGA→CHS New York to Charleston | March 9, 2024 | 1 | — |
| LGA→DCA New York to Washington | September 5, 2023 – January 7, 2024 | 38 | — |
| BOS→DCA Boston to Washington | October 29, 2023 – December 15, 2023 | 9 | — |
| DCA→BOS Washington to Boston | December 7–15, 2023 | 9 | — |
| DCA→LGA Washington to New York | September 5, 2023 – November 4, 2023 | 31 | — |
| BOS→LGA Boston to New York | October 30, 2023 – November 3, 2023 | 5 | — |
| STL→LGA St. Louis to New York | October 9–27, 2023 | 17 | — |
| LGA→RDU New York to Raleigh–Durham | October 8, 2023 | 1 | — |
| BUF→LGA Buffalo to New York | October 6–7, 2023 | 2 | — |
| BOS→MKE Boston to Milwaukee | July 10, 2023 – September 4, 2023 | 48 | — |
| MKE→BOS Milwaukee to Boston | July 10, 2023 – September 4, 2023 | 48 | — |
| BOS→EWR Boston to Newark | July 2–9, 2023 | 6 | — |
Because the same number has served different journeys, the statistics above describe only the route YX5631 currently operates. Blending them would produce an average of two different flights.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
9 min late
against a median of 16 min early
Percentiles over 725 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – July 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| YX5631 this flight | Republic Airways | 93.7% | 16 min early | 725 |
| YX4716 | Republic Airways | 89.9% | 9 min early | 1,105 |
| YX4726 | Republic Airways | 69.3% | 6 min early | 675 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. YX5631 is placed in the same ordering rather than left out of it; the rows around it are the most punctual departures on the route, not all of them, so this is a comparison and not a rank. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 725 records of YX5631 operating IND → BOS, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
Full methodology · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
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