Flight number record
DL 1147
Delta Air Lines · Atlanta to Chicago
- Route
- ATL → ORD
- Departs
- 09:00
- Flights
- 351
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1147, check with Delta Air Lines.
DL 1147 lands a B, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That rests on 351 flights, with a median arrival 4 minutes early.
Key figures
On time
79.0%
Arrivals under 15 minutes late, of 338 completed flights
Avg delay
46 min
Across delayed arrivals only, not all flights
Cancelled
2.85%
National rate is 1.89%
1 hour+ late
4.4%
National rate is 8.3%
These figures cover 351 flights between September 2025 and August 2026. The median arrival is 4 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Schedule
When DL 1147 flies
DL 1147 flies ATL to ORD without a single fixed slot. Its most common scheduled departure was 09:00, used on 59 of 351 flights, with 09:02 (53 flights) and 09:08 (40 flights) next.
- Departs 09:0059 flights16.8%
- Departs 09:0253 flights15.1%
- Departs 09:0840 flights11.4%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 09:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and DL 1147 runs 5 points worse at 79.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Against the route
DL 1147 next to ATL to ORD
Every carrier on ATL to ORD combined arrived on time 69.0% of the time across 6,493 flights, so DL 1147 is 10 points ahead of it. Delta flew 2,631 flights on the same city pair under all its flight numbers, including this one, and those ran 67.6% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 2 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1147thin sample | 351 | 79.0% | 46 min | 2.85% | B |
| All Delta Air Lines on ATL–ORD | 2,631 | 67.6% | 63 min | 2.20% | C |
| All carriers on ATL–ORD | 6,493 | 69.0% | 83 min | 2.40% | C |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1147 quarter by quarter
DL 1147 did not run the same all year. Its best quarter was Jul–Sep 2025 at 96.7% on time and its weakest Oct–Dec 2025 at 66.7%, a swing of 30 points on roughly 70 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 202530 flights96.7%
- Oct–Dec 202592 flights66.7%
- Jan–Mar 202690 flights71.6%
- Apr–Jun 202686 flights85.9%
- Jul–Sep 202653 flights90.4%
Scale runs 60% to 100%.
By weekday, DL 1147 did best on Wednesday at 89.4% on time and worst on Tuesday at 71.1%. Each day rests on about 50 flights, so a gap of 18 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1147 runs when it is late
Most of the lateness is short. 36 of the 71 late arrivals were under half an hour behind, and 15 reached an hour or more.
- 15+ min early48 flights14.2%
- Within 15 min219 flights64.8%
- 15–29 min late36 flights10.7%
- 30–59 min late20 flights5.9%
- 1–2 hours late7 flights2.1%
- 2+ hours late8 flights2.4%
Scale runs 0% to 100%.
Share of 338 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 44 departures that left 15 minutes late or more, only 4 made it up before arrival. In the other direction, 31 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at ORD.
The worst days
Worst days for DL 1147
The latest arrival of the period was on 30 November 2025, 3 hours 9 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 November 2025 | 3 hours 9 minutes | National Airspace System |
| 7 December 2025 | 3 hours 1 minute | National Airspace System |
| 14 January 2026 | 2 hours 40 minutes | National Airspace System |
| 29 November 2025 | 2 hours 29 minutes | National Airspace System |
| 3 May 2026 | 2 hours 22 minutes | Carrier |
Delay causes
Why DL 1147 runs late
National Airspace System accounts for 60% of the 3,252 delay minutes carriers reported here, and the remaining four split what is left.
- 60%National Airspace System
- 35%Carrier
- 5%Late-arriving aircraft
- 1%Extreme weather
60% 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 1,943 minutes out of 3,252, against a national NAS share of 21%. The split is drawn from 3,252 delay minutes reported on DL 1147.
Cancellations run at 2.85%, against 1.89% nationally. That is roughly one flight in 40 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
Badly late arrivals are rare here: only 4.4% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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.
DL 1147 is not only a ATL to ORD flight. It also flew ORD to ATL (350 flights, 79.3% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 351 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| ORD to ATLthin sample | 350 | 79.3% | 66 min | 3.14% | B− |
What to do with this
Booking DL 1147
For a booking, the cancellation rate is the figure to plan around on DL 1147: 2.85% of its 351 scheduled flights did not operate. A late arrival costs about 45 minutes, 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 route57.6%
- United Airlines 516 on the same route70.8%
- Delta Air Lines 1477 on the same route72.9%
- Delta Air Lines 2879 on the same route45.6%
- Frontier Airlines 1441 on the same route72.7%
- Delta Air Lines 1199 on the same route70.6%
- 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.