Flight number record
DL 1247
Delta Air Lines · Chicago to Atlanta
- Route
- ORD → ATL
- Departs
- 06:45
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1247, check with Delta Air Lines.
DL 1247 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs close to two hours. That rests on 365 flights, with a median arrival 14 minutes early.
Set against the rest of the country, DL 1247's record is 11 points better than the US average of 77.3%. That gap is worth roughly 105 fewer late arrivals for every thousand flights.
Key figures
On time
87.8%
Arrivals under 15 minutes late, of 362 completed flights
Avg delay
101 min
Across delayed arrivals only, not all flights
Cancelled
0.82%
National rate is 1.89%
1 hour+ late
4.7%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 14 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.
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Schedule
When DL 1247 flies
DL 1247 flies ORD to ATL without a single fixed slot. Its most common scheduled departure was 06:45, used on 120 of 365 flights, with 07:10 (60 flights) and 06:35 (53 flights) next.
- Departs 06:45120 flights32.9%
- Departs 07:1060 flights16.4%
- Departs 06:3553 flights14.5%
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 06:45 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 1247 runs level with that at 87.8%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
DL 1247 next to ORD to ATL
Every carrier on ORD to ATL combined arrived on time 74.1% of the time across 6,495 flights, so DL 1247 is 14 points ahead of it. Delta flew 2,629 flights on the same city pair under all its flight numbers, including this one, and those ran 79.8% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 7 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1247 | 365 | 87.8% | 101 min | 0.82% | A+ |
| All Delta Air Lines on ORD–ATL | 2,629 | 79.8% | 84 min | 2.40% | B |
| All carriers on ORD–ATL | 6,495 | 74.1% | 81 min | 2.31% | C |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1247 quarter by quarter
DL 1247 did not run the same all year. Its best quarter was Jul–Sep 2025 at 96.7% on time and its weakest Jan–Mar 2026 at 82.0%, a swing of 15 points on roughly 73 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 flights87.0%
- Jan–Mar 202690 flights82.0%
- Apr–Jun 202691 flights91.1%
- Jul–Sep 202662 flights88.5%
Scale runs 75% to 100%.
By weekday, DL 1247 did best on Tuesday at 96.2% on time and worst on Saturday at 82.4%. Each day rests on about 52 flights, so a gap of 14 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1247 runs when it is late
DL 1247 often beats the schedule: 178 of 362 completed flights, 49%, arrived 15 minutes or more early. The 44 late arrivals split 15 under half an hour, 12 between 30 and 60 minutes, and 17 an hour or more.
- 15+ min early178 flights49.2%
- Within 15 min140 flights38.7%
- 15–29 min late15 flights4.1%
- 30–59 min late12 flights3.3%
- 1–2 hours late8 flights2.2%
- 2+ hours late9 flights2.5%
Scale runs 0% to 100%.
Share of 362 completed flights by arrival against schedule.
9 of 36 late departures made up the time and arrived on time, 25% of them. 17 flights left on time and still arrived late.
The worst days
Worst days for DL 1247
The latest arrival of the period was on 15 November 2025, 11 hours 26 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 15 November 2025 | 11 hours 26 minutes | Carrier |
| 6 May 2026 | 10 hours 58 minutes | Carrier |
| 30 November 2025 | 6 hours 2 minutes | Carrier |
| 22 August 2026 | 6 hours 1 minute | Carrier |
| 7 December 2025 | 4 hours 50 minutes | National Airspace System |
Delay causes
Why DL 1247 runs late
Carrier accounts for 72% of the 4,437 delay minutes carriers reported here, and the remaining four split what is left.
- 72%Carrier
- 21%National Airspace System
- 4%Late-arriving aircraft
- 3%Extreme weather
The largest share of delay minutes, 72%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,211 of the 4,437 delay minutes reported here. The split is drawn from 4,437 delay minutes reported on DL 1247.
Cancellations are rare at 0.82%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 4.7% 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.
Every one of the 365 flights under DL 1247 in the data flew ORD to ATL. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 365 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 1247
For a booking, DL 1247 has one of the better records a US domestic flight can show: 87.8% on time and 0.82% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- ORD to ATL, every carrier and departure
- ATL to ORD, the return direction
- Delta Air Lines 1264 on the same route91.3%
- United Airlines 356 on the same route73.1%
- Delta Air Lines 1147 on the same route79.3%
- Delta Air Lines 1178 on the same route85.4%
- Frontier Airlines 1596 on the same route72.4%
- United Airlines 1398 on the same route56.2%
- Chicago O'Hare International (ORD) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) 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
- Worst months to fly in the US, ranked by the data
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.