Flight profile · Delta Air Lines
DL1597
St. Louis (STL) to Minneapolis (MSP) · scheduled 6:00 AM – 7:46 AM
How DL1597 performs
785 operations, June 2024 – July 2026.
DL1597 arrived on time 89.8% of the time, against 82.2% for all STL → MSP flights, so this departure is 7.6 percentage points better than the route as a whole. Against Delta Air Lines’ own flights on this route it is 2.6 points better.
Source: US DOT Bureau of Transportation Statistics · 785 operations, June 2024 – July 2026 · If DL1597 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where DL1597 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 |
|---|---|---|---|---|---|
| DL1597 | 89.8% | 0.89% | -13 min | 3.3% | 785 |
| Delta Air Lines on STL → MSP | 87.2% | 0.81% | -13 min | 5.5% | 3,314 |
| All STL → MSP flights | 82.2% | 0.77% | -9 min | 6.4% | 6,003 |
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
Why DL1597 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 DL1597 on STL → MSP. 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 DL1597 comes in late, and what that does to the departure.
DL1597 is usually the aircraft’s first flight of the day: the schedule gives it a median of 6.9 hours on the ground at STL, so its “inbound” is mostly the aircraft’s arrival the evening before.
When the aircraft came in 15 or more minutes late, DL1597 pushed back an average of 14 minutes late; when it came in on time or early, an average of 1 minute early.
Each departure is matched to the flight the same aircraft flew into STL just before it, using the tail number in the DOT file, 765 of 778 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 |
|---|---|---|---|
| DL1597 | 23% | 9% | 7% |
| 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 DL1597’s aircraft landed 15 or more minutes late is lower than the network’s and, once the aircraft was late, how often DL1597 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 STL late, does that still matter by the time it reaches MSP?
DL1597 pushes back an average of 4.2 minutes late and reaches the gate at MSP an average of 0.6 minutes early. The 4.9 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 13.7 minutes on the taxiways at STL is about what any departure from the airport in that hour spends.
On arrival at MSP, DL1597 spends 6.5 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 MSP 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 MSP. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 15,316 departures from STL scheduled in the clock hour DL1597 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at MSP (369,815 flights), not just DL1597’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
The hour it leaves STL
Part of any flight’s record belongs to the clock rather than to the flight. DL1597 has one departure time, so this is what that time is worth.
On-time arrival rate. 15,316 departures from STL are scheduled in the 6 AM–7 AM hour over the period, against 198,650 across the whole day.
DL1597 is scheduled out of STL at 6:00 AM, in the 6 AM–7 AM bank. Departures from STL in that hour arrive on time 90.1% of the time against 79.1% across the airport’s whole day — the slot alone is worth 11.0 points better before anything about this particular flight is considered.
The two airport figures cover every departure from STL 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 DL1597 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→JAX Boston to Jacksonville | May 7, 2024 – June 6, 2024 | 26 | — |
| JAX→BOS Jacksonville to Boston | May 7, 2024 – June 6, 2024 | 26 | — |
| BNA→BOS Nashville to Boston | May 11, 2024 – June 1, 2024 | 4 | — |
| BOS→BNA Boston to Nashville | May 11–18, 2024 | 2 | — |
| ATL→AUS Atlanta to Austin | March 10, 2024 – May 6, 2024 | 58 | — |
| AUS→ATL Austin to Atlanta | March 10, 2024 – May 6, 2024 | 58 | — |
| SLC→IAH Salt Lake City to Houston | January 8, 2024 – March 9, 2024 | 62 | — |
| DTW→DEN Detroit to Denver | July 1, 2023 – January 7, 2024 | 182 | 89.0% |
| LAS→SLC Las Vegas to Salt Lake City | December 7–15, 2023 | 9 | — |
| DEN→DTW Denver to Detroit | July 1, 2023 – November 24, 2023 | 74 | — |
Because the same number has served different journeys, the statistics above describe only the route DL1597 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.
15 min late
against a median of 13 min early
Percentiles over 785 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 785 records of DL1597 operating STL → MSP, 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
Analysis last recomputed