Flight profile · Delta Air Lines
DL2879
Atlanta (ATL) to Chicago (ORD) · scheduled 5:25 PM – 6:49 PM
How DL2879 performs
887 operations, July 2023 – July 2026.
DL2879 arrived on time 54.7% of the time, against 74.1% for all ATL → ORD flights, so this departure is 19.4 percentage points worse than the route as a whole. Against Delta Air Lines’ own flights on this route it is 18.2 points worse.
Source: US DOT Bureau of Transportation Statistics · 887 operations, July 2023 – July 2026 · If DL2879 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 DL2879 compares to other flight numbers, not just to itself.
Which day you fly matters unusually much here, a wider weekday spread than 97% of 1,710 comparable flight numbers.
65.6% on time on a typical Wednesday, against 44.2% on a Sunday.
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 DL2879 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
Ask for the position of DL2879 right now, if receivers on the ground are hearing it. Nothing is requested until you press the button.
Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| DL2879 | 54.7% | 1.47% | 11 min | 13.4% | 887 |
| Delta Air Lines on ATL → ORD | 72.9% | 1.39% | 0 min | 8.1% | 7,714 |
| All ATL → ORD flights | 74.1% | 1.68% | -3 min | 9.5% | 18,588 |
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
Why DL2879 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
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for DL2879 on ATL → ORD. 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 DL2879 comes in late, and what that does to the departure.
When the aircraft came in 15 or more minutes late, DL2879 pushed back an average of 46 minutes late; when it came in on time or early, an average of 13 minutes late.
Each departure is matched to the flight the same aircraft flew into ATL just before it, using the tail number in the DOT file, 779 of 874 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 |
|---|---|---|---|
| DL2879 | 17% | 64% | 21% |
| Network, same turn | 17% | 68% | 9% |
The schedule leaves a normal turn: enough time to clean and board if the aircraft is on time, little to spare if it is not.
The network row is every flight with a scheduled turn of 60 to 89 minutes. How often DL2879’s aircraft landed 15 or more minutes late is about the same as the network’s and, once the aircraft was late, how often DL2879 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 ATL late, does that still matter by the time it reaches ORD?
DL2879 pushes back an average of 20.7 minutes late and arrives a further 5.7 minutes behind that. This departure loses ground between the two gates rather than recovering it, so a late pushback here tends to get worse on the way, not better. It spends 21.9 minutes on the taxiways at ATL, 5.0 minutes longer than a typical ATL departure in the same hour.
On arrival at ORD, DL2879 spends 18.0 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 about what any arrival at ORD 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 ORD. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 52,446 departures from ATL scheduled in the clock hour DL2879 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at ORD (952,666 flights), not just DL2879’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
The hour it leaves ATL
Part of any flight’s record belongs to the clock rather than to the flight. DL2879 has one departure time, so this is what that time is worth.
On-time arrival rate. 52,446 departures from ATL are scheduled in the 5 PM–6 PM hour over the period, against 1,012,247 across the whole day.
DL2879 is scheduled out of ATL at 5:25 PM, in the 5 PM–6 PM bank. Departures from ATL in that hour arrive on time 72.3% of the time against 78.7% across the airport’s whole day — the slot alone is worth 6.4 points worse before anything about this particular flight is considered.
The two airport figures cover every departure from ATL 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 DL2879 run worse on particular days?
Wednesday is historically the most reliable day and Sunday the least, a gap of 21.4 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 DL2879 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 |
|---|---|---|---|
| ORD→ATL Chicago to Atlanta | September 10, 2023 – June 5, 2026 | 435 | 66.0% |
| ATL→CAE Atlanta to Columbia | January 20–31, 2025 | 4 | — |
| CAE→ATL Columbia to Atlanta | January 20–31, 2025 | 4 | — |
| DTW→GSP Detroit to Greenville/Greer/Spartanburg | June 8–30, 2024 | 5 | — |
| MSP→AUS Minneapolis to Austin | May 7, 2024 – June 6, 2024 | 31 | — |
| BIS→MSP Bismarck to Minneapolis | January 7, 2024 | 1 | — |
| LGA→BUF New York to Buffalo | December 16, 2023 – January 6, 2024 | 22 | — |
| ATL→SFO Atlanta to San Francisco | November 6, 2023 – December 13, 2023 | 15 | — |
| ORD→SEA Chicago to Seattle | November 24, 2023 | 1 | — |
Because the same number has served different journeys, the statistics above describe only the route DL2879 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.
76 min late
against a median of 11 min late
DL2879 has an average that understates its risk: a typical arrival is 11 min late, but the worst tenth are 65 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 887 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 |
|---|---|---|---|---|
| DL1178 | Delta Air Lines | 88.3% | 5 min early | 916 |
| DL1147 | Delta Air Lines | 80.4% | 3 min early | 1,054 |
| UA516 | United Airlines | 78.3% | 6 min early | 989 |
| DL1199 | Delta Air Lines | 73.9% | 2 min early | 732 |
| DL1477 | Delta Air Lines | 72.4% | 0 min early | 977 |
| DL2738 | Delta Air Lines | 68.7% | 3 min late | 1,028 |
| UA1046 | United Airlines | 68.2% | 4 min late | 939 |
| DL2879 this flight | Delta Air Lines | 54.7% | 11 min late | 887 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. DL2879 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 887 records of DL2879 operating ATL → ORD, 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