Flight profile · Republic Airways
YX4585
Boston (BOS) to Indianapolis (IND) · scheduled 5:00 PM – 7:45 PM
How YX4585 performs
855 operations, July 2023 – July 2026.
YX4585 arrived on time 71.4% of the time, against 84.7% for all BOS → IND flights, so this departure is 13.3 percentage points worse than the route as a whole. Against Republic Airways’ own flights on this route it is 13.6 points worse.
Source: US DOT Bureau of Transportation Statistics · 855 operations, July 2023 – July 2026 · If YX4585 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 YX4585 compares to other flight numbers, not just to itself.
This flight runs unusually far behind the carrier's own average on this route, worse than 94% of 11,589 comparable flight numbers.
71.4% on time for this specific departure, against 85.0% for the same carrier's other flights on this route.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – 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 YX4585 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 |
|---|---|---|---|---|---|
| YX4585 | 71.4% | 2.57% | -6 min | 12.3% | 855 |
| Republic Airways on BOS → IND | 85.0% | 1.63% | -13 min | 6.3% | 5,891 |
| All BOS → IND flights | 84.7% | 1.63% | -13 min | 6.3% | 6,128 |
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
Why YX4585 runs late
Where US DOT attributed the delay minutes on this flight.
the inbound aircraft was late, so this flight started late
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 YX4585 on BOS → IND. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies YX4585 comes in late, and what that does to the departure.
When the aircraft came in 15 or more minutes late, YX4585 pushed back an average of 56 minutes late; when it came in on time or early, an average of 3 minutes early.
Each departure is matched to the flight the same aircraft flew into BOS just before it, using the tail number in the DOT file, 805 of 833 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 |
|---|---|---|---|
| YX4585 | 28% | 73% | 6% |
| Network, same turn | 18% | 92% | 12% |
The schedule leaves little slack between the inbound landing and this departure, so a late arrival has almost nowhere to go but into the departure.
The network row is every flight with a scheduled turn of 30 to 44 minutes. How often YX4585’s aircraft landed 15 or more minutes late is higher than the network’s and, once the aircraft was late, how often YX4585 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 July 2023 – July 2026
From pushback to gate
When it leaves BOS late, does that still matter by the time it reaches IND?
YX4585 pushes back an average of 16.5 minutes late and reaches the gate at IND an average of 12.2 minutes late. The 4.2 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. It spends 23.4 minutes on the taxiways at BOS, 1.0 minutes shorter than a typical BOS departure in the same hour.
On arrival at IND, YX4585 spends 10.0 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 3.0 minutes longer than a typical IND arrival (7.0 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 IND. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 30,895 departures from BOS scheduled in the clock hour YX4585 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at IND (147,137 flights), not just YX4585’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
The hour it leaves BOS
Part of any flight’s record belongs to the clock rather than to the flight. YX4585 has one departure time, so this is what that time is worth.
On-time arrival rate. 30,895 departures from BOS are scheduled in the 5 PM–6 PM hour over the period, against 440,893 across the whole day.
YX4585 is scheduled out of BOS at 5:00 PM, in the 5 PM–6 PM bank. Departures from BOS in that hour arrive on time 66.7% of the time against 77.2% across the airport’s whole day — the slot alone is worth 10.5 points worse before anything about this particular flight is considered.
The two airport figures cover every departure from BOS 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 · July 2023 – July 2026 · Hours below 120 departures are not scored.
By day of week
Does YX4585 run worse on particular days?
Thursday is historically the most reliable day and Sunday the least, a gap of 12.0 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Days with fewer than 120 operations are not scored.
Other routes YX4585 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 |
|---|---|---|---|
| BOS→LGA Boston to New York | September 3, 2025 – October 5, 2025 | 28 | — |
| BOS→EYW Boston to Key West | November 9, 2024 – December 14, 2024 | 6 | — |
| CHS→ORD Charleston to Chicago | March 9–30, 2024 | 4 | — |
| ORD→CHS Chicago to Charleston | March 9–30, 2024 | 4 | — |
| IND→BOS Indianapolis to Boston | November 5, 2023 – February 14, 2024 | 87 | — |
Because the same number has served different journeys, the statistics above describe only the route YX4585 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.
72 min late
against a median of 6 min early
YX4585 has an average that understates its risk: a typical arrival is 6 min early, but the worst tenth are 78 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 855 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| YX4725 | Republic Airways | 93.3% | 18 min early | 864 |
| YX5627 | Republic Airways | 87.5% | 13 min early | 673 |
| YX5616 | Republic Airways | 76.3% | 11 min early | 687 |
| YX4585 this flight | Republic Airways | 71.4% | 6 min early | 855 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. YX4585 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 855 records of YX4585 operating BOS → IND, 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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