Flight profile · Republic Airways
YX5604
Memphis (MEM) to Boston (BOS) · scheduled 6:10 AM – 10:10 AM
How YX5604 performs
670 operations, June 2024 – July 2026.
Source: US DOT Bureau of Transportation Statistics · 670 operations, June 2024 – July 2026 · If YX5604 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where YX5604 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 |
|---|---|---|---|---|---|
| YX5604 | 91.0% | 0.90% | -14 min | 4.1% | 670 |
| Republic Airways on MEM → BOS | 91.5% | 1.06% | -13 min | 3.8% | 1,411 |
| All MEM → BOS flights | 91.5% | 1.06% | -13 min | 3.8% | 1,411 |
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
Why YX5604 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for YX5604 on MEM → 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 YX5604 comes in late, and what that does to the departure.
YX5604 is usually the aircraft’s first flight of the day: the schedule gives it a median of 7 hours on the ground at MEM, so its “inbound” is mostly the aircraft’s arrival the evening before.
When the aircraft came in 15 or more minutes late, YX5604 pushed back an average of 3 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 MEM just before it, using the tail number in the DOT file, 525 of 664 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 |
|---|---|---|---|
| YX5604 | 34% | 11% | 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 YX5604’s aircraft landed 15 or more minutes late is higher than the network’s and, once the aircraft was late, how often YX5604 left 15 or more minutes late is about the same as 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 MEM late, does that still matter by the time it reaches BOS?
YX5604 pushes back an average of 3.8 minutes late and reaches the gate at BOS an average of 4.9 minutes early. The 8.7 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 15.1 minutes on the taxiways at MEM is about what any departure from the airport in that hour spends.
On arrival at BOS, YX5604 spends 9.8 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 about what any arrival at BOS spends on the ground before reaching the gate.
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 10,699 departures from MEM scheduled in the clock hour YX5604 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 YX5604’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
The hour it leaves MEM
Part of any flight’s record belongs to the clock rather than to the flight. YX5604 has one departure time, so this is what that time is worth.
On-time arrival rate. 10,699 departures from MEM are scheduled in the 6 AM–7 AM hour over the period, against 72,794 across the whole day.
YX5604 is scheduled out of MEM at 6:10 AM, in the 6 AM–7 AM bank. Departures from MEM in that hour arrive on time 89.7% of the time against 81.2% across the airport’s whole day — the slot alone is worth 8.5 points better before anything about this particular flight is considered.
The two airport figures cover every departure from MEM 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 YX5604 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→ORD New York to Chicago | February 15, 2026 – March 1, 2026 | 3 | — |
| RDU→BOS Raleigh–Durham to Boston | January 11, 2026 – February 8, 2026 | 7 | — |
| LGA→MEM New York to Memphis | December 24, 2025 – January 1, 2026 | 4 | — |
| LGA→ORF New York to Norfolk | November 16, 2024 – December 14, 2024 | 4 | — |
| CLE→JFK Cleveland to New York | November 28–29, 2024 | 2 | — |
| LGA→JAX New York to Jacksonville | May 7, 2024 – June 6, 2024 | 26 | — |
| JAX→LGA Jacksonville to New York | May 7, 2024 – June 6, 2024 | 23 | — |
| JAX→JFK Jacksonville to New York | April 9, 2024 – May 6, 2024 | 28 | — |
| JFK→JAX New York to Jacksonville | April 9, 2024 – May 6, 2024 | 28 | — |
| BOS→ORD Boston to Chicago | March 16, 2024 – April 6, 2024 | 4 | — |
| BOS→MKE Boston to Milwaukee | January 8, 2024 – March 9, 2024 | 62 | — |
| MKE→BOS Milwaukee to Boston | February 15, 2024 – March 9, 2024 | 23 | — |
| BOS→BWI Boston to Baltimore | October 9, 2023 – January 7, 2024 | 34 | — |
| BWI→BOS Baltimore to Boston | December 26, 2023 – January 6, 2024 | 10 | — |
| ORF→LGA Norfolk to New York | December 24, 2023 – January 1, 2024 | 4 | — |
| PIT→DTW Pittsburgh to Detroit | November 5, 2023 – December 15, 2023 | 40 | — |
| LGA→DCA New York to Washington | October 29, 2023 – November 3, 2023 | 6 | — |
| LGA→BOS New York to Boston | September 5–15, 2023 | 10 | — |
| BOS→DCA Boston to Washington | July 2, 2023 – September 4, 2023 | 56 | — |
| DCA→BOS Washington to Boston | July 2, 2023 – September 4, 2023 | 54 | — |
| IND→LGA Indianapolis to New York | July 15–29, 2023 | 3 | — |
Because the same number has served different journeys, the statistics above describe only the route YX5604 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.
11 min late
against a median of 14 min early
Percentiles over 670 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – July 2026
Data and methodology
Calculated by FlyerIntel from 670 records of YX5604 operating MEM → 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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