Flight number record
DL 2879
Delta Air Lines · Atlanta to Chicago
- Route
- ATL → ORD
- Departs
- 17:42
- Flights
- 340
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s DL 2879, check with Delta Air Lines.
DL 2879 earns an F, which is as low as this site's scale goes for a reason. Only 46.8% of flights arrive inside the 15-minute window, 31 points worse than the national rate of 77.6%. Late arrivals average about an hour. Treat any tight connection here as a coin flip. That rests on 340 flights, with a median arrival 16 minutes late.
The national on-time rate over the same period is 77.6%, so DL 2879 runs 31 points behind the country as a whole. Across a thousand flights that is about 308 extra late arrivals.
Key figures
On time
46.8%
Arrivals under 15 minutes late, of 327 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
2.94%
National rate is 1.81%
1 hour+ late
14.7%
National rate is 8.1%
These figures cover 340 flights between July 2025 and June 2026. Beyond the headline rate, 14.7% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Schedule
When DL 2879 flies
DL 2879 flies ATL to ORD without a single fixed slot. Its most common scheduled departure was 17:42, used on 65 of 340 flights, with 17:29 (38 flights) and 17:38 (34 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 17:4265 flights19.1%
- Departs 17:2938 flights11.2%
- Departs 17:3834 flights10.0%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 17:42 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 2879 runs 21 points worse at 46.8%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
Against the route
DL 2879 next to ATL to ORD
Every carrier on ATL to ORD combined arrived on time 70.6% of the time across 6,406 flights, so DL 2879 is 24 points behind it. Delta flew 2,625 flights on the same city pair under all its flight numbers, including this one, and those ran 69.1% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 35 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 2879thin sample | 340 | 46.8% | 62 min | 2.94% | F |
| All Delta Air Lines on ATL–ORD | 2,625 | 69.1% | 63 min | 2.21% | C |
| All carriers on ATL–ORD | 6,406 | 70.6% | 81 min | 2.34% | C |
| Delta Air Lines, whole network | 1,038,570 | 81.6% | 71 min | 1.62% | B |
Across the year
DL 2879 quarter by quarter
DL 2879 did not run the same all year. Its best quarter was Jul–Sep 2025 at 56.6% on time and its weakest Jan–Mar 2026 at 39.1%, a swing of 18 points on roughly 85 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202587 flights56.6%
- Oct–Dec 202589 flights40.2%
- Jan–Mar 202674 flights39.1%
- Apr–Jun 202690 flights50.0%
Scale runs 30% to 60%. Rows with fewer than 30 flights show a dash.
By weekday, DL 2879 did best on Wednesday at 63.3% on time and worst on Sunday at 34.1%. Each day rests on about 49 flights, so a gap of 29 points is worth noticing but could still narrow in another year.
Delay causes
Why DL 2879 runs late
One category carries most of the weight here. National Airspace System accounts for 55% of the 11,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 55%National Airspace System
- 29%Carrier
- 12%Late-arriving aircraft
- 4%Extreme weather
- 0%Security
55% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 5,962 minutes out of 11,000, against a national NAS share of 21%. The split is drawn from 10,796 delay minutes reported on DL 2879.
Cancellations run at 2.94%, against 1.81% nationally. That is roughly one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and routes
What a delay on this flight costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 14.7% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 606 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The same number turns up on one other city pair in the data, including ORD to ATL (183), but none flew often enough under DL 2879 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ATL to ORD only.
One caution: this is a thin sample. 340 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking DL 2879
For a booking, the cancellation rate is the figure to plan around on DL 2879: 2.94% of its 340 scheduled flights did not operate. A late arrival costs about an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- ATL to ORD, every carrier and departure
- ORD to ATL, the return direction
- Delta Air Lines 2738 on the same route60.6%
- United Airlines 516 on the same route72.9%
- Delta Air Lines 1147 on the same route79.2%
- Frontier Airlines 1441 on the same route70.8%
- United Airlines 1046 on the same route58.9%
- Delta Air Lines 1178 on the same route88.0%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- What a cancellation rate actually tells you (and what it hides)
A flight number here means Delta Air Lines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.