Flight number record
DL 1066
Delta Air Lines · San Antonio to Atlanta
- Route
- SAT → ATL
- Departs
- 06:40
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1066, check with Delta Air Lines.
DL 1066 earns an A. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 16 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 10 minutes early.
Set against the rest of the country, DL 1066's record is 16 points better than the US average of 77.3%. That gap is worth roughly 158 fewer late arrivals for every thousand flights.
Key figures
On time
93.1%
Arrivals under 15 minutes late, of 360 completed flights
Avg delay
106 min
Across delayed arrivals only, not all flights
Cancelled
1.10%
National rate is 1.89%
1 hour+ late
2.5%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 10 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 1066 flies
DL 1066 flies SAT to ATL without a single fixed slot. Its most common scheduled departure was 06:40, used on 67 of 365 flights, with 06:30 (64 flights) next.
- Departs 06:4067 flights18.4%
- Departs 06:3064 flights17.5%
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 06:40 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 1066 runs 4 points better at 93.1%. 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 1066 next to SAT to ATL
Every carrier on SAT to ATL combined arrived on time 85.9% of the time across 2,962 flights, so DL 1066 is 7 points ahead of it. Delta flew 2,596 flights on the same city pair under all its flight numbers, including this one, and those ran 87.4% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1066 | 365 | 93.1% | 106 min | 1.10% | A |
| All Delta Air Lines on SAT–ATL | 2,596 | 87.4% | 79 min | 1.93% | A |
| All carriers on SAT–ATL | 2,962 | 85.9% | 76 min | 1.72% | A |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1066 quarter by quarter
DL 1066 did not run the same all year. Its best quarter was Jul–Sep 2025 at 100.0% on time and its weakest Apr–Jun 2026 at 90.0%, a swing of 10 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 flights100.0%
- Oct–Dec 202592 flights92.2%
- Jan–Mar 202690 flights94.4%
- Apr–Jun 202691 flights90.0%
- Jul–Sep 202662 flights93.4%
Scale runs 80% to 100%.
By weekday, DL 1066 ranged from 86.3% on Saturday to 98.1% on Wednesday. With about 52 flights behind each day, a spread of 12 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late DL 1066 runs when it is late
DL 1066 often beats the schedule: 113 of 360 completed flights, 31%, arrived 15 minutes or more early. The 25 late arrivals split 12 under half an hour, 4 between 30 and 60 minutes, and 9 an hour or more.
- 15+ min early113 flights31.4%
- Within 15 min222 flights61.7%
- 15–29 min late12 flights3.3%
- 30–59 min late4 flights1.1%
- 1–2 hours late4 flights1.1%
- 2+ hours late5 flights1.4%
Scale runs 0% to 100%.
Share of 360 completed flights by arrival against schedule.
6 of 24 late departures made up the time and arrived on time, 25% of them. Only 7 left on time and still arrived late.
The worst days
Worst days for DL 1066
The latest arrival of the period was on 11 August 2026, 12 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 |
|---|---|---|
| 11 August 2026 | 12 hours 26 minutes | Carrier |
| 25 January 2026 | 7 hours | Extreme weather |
| 3 May 2026 | 5 hours 29 minutes | Carrier |
| 29 December 2025 | 3 hours 57 minutes | Carrier |
| 27 January 2026 | 3 hours 12 minutes | Carrier |
Delay causes
Why DL 1066 runs late
Carrier accounts for 65% of the 2,645 delay minutes carriers reported here, and the remaining four split what is left.
- 65%Carrier
- 19%Extreme weather
- 16%National Airspace System
Extreme weather accounts for 19% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.2 times the usual weather exposure. The split is drawn from 2,645 delay minutes reported on DL 1066.
Cancellations sit at 1.10% against a national 1.89%, which is ordinary. Diversions add another 0.27%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 2.5% 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 874 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 1066 in the data flew SAT 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 1066
For a booking, DL 1066 has one of the better records a US domestic flight can show: 93.1% on time and 1.10% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- SAT to ATL, every carrier and departure
- ATL to SAT, the return direction
- Delta Air Lines 1073 on the same route93.8%
- Delta Air Lines 1408 on the same route80.1%
- Delta Air Lines 998 on the same route92.2%
- Delta Air Lines 1676 on the same route86.7%
- San Antonio International (SAT) 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.