Flight number record
DL 1040
Delta Air Lines · Austin to Detroit
- Route
- AUS → DTW
- Departs
- 05:20
- Flights
- 359
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1040, check with Delta Air Lines.
DL 1040 earns an A. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 17 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 50 minutes. That rests on 359 flights, with a median arrival 13 minutes early.
Set against the rest of the country, DL 1040's record is 17 points better than the US average of 77.3%. That gap is worth roughly 165 fewer late arrivals for every thousand flights.
Key figures
On time
93.8%
Arrivals under 15 minutes late, of 352 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
1.95%
National rate is 1.89%
1 hour+ late
1.1%
National rate is 8.3%
These figures cover 359 flights between September 2025 and August 2026. The median arrival is 13 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 1040 flies
DL 1040 flies AUS to DTW without a single fixed slot. Its most common scheduled departure was 05:20, used on 140 of 359 flights, with 05:30 (75 flights) and 05:12 (60 flights) next.
- Departs 05:20140 flights39.0%
- Departs 05:3075 flights20.9%
- Departs 05:1260 flights16.7%
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 05:20 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 1040 runs 5 points better at 93.8%. 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 1040 next to AUS to DTW
Every carrier on AUS to DTW combined arrived on time 87.4% of the time across 1,309 flights, so DL 1040 is 6 points ahead of it. Delta flew 1,291 flights on the same city pair under all its flight numbers, including this one, and those ran 87.6% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 13 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1040thin sample | 359 | 93.8% | 48 min | 1.95% | A |
| All Delta Air Lines on AUS–DTW | 1,291 | 87.6% | 101 min | 1.39% | A |
| All carriers on AUS–DTW | 1,309 | 87.4% | 99 min | 1.38% | A |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1040 quarter by quarter
DL 1040 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 86.0%, a swing of 11 points on roughly 72 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 flights96.7%
- Jan–Mar 202688 flights86.0%
- Apr–Jun 202691 flights96.6%
- Jul–Sep 202658 flights94.6%
Scale runs 80% to 100%.
By weekday, DL 1040 ranged from 90.0% on Sunday to 96.2% on Tuesday. With about 51 flights behind each day, a spread of 6 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late DL 1040 runs when it is late
DL 1040 often beats the schedule: 160 of 352 completed flights, 45%, arrived 15 minutes or more early. Most of the lateness is short. 14 of the 22 late arrivals were under half an hour behind, and 4 reached an hour or more.
- 15+ min early160 flights45.5%
- Within 15 min170 flights48.3%
- 15–29 min late14 flights4.0%
- 30–59 min late4 flights1.1%
- 1–2 hours late2 flights0.6%
- 2+ hours late2 flights0.6%
Scale runs 0% to 100%.
Share of 352 completed flights by arrival against schedule.
Only 12 of 352 completed flights left 15 minutes late or more, too few to say how often the time is made up.
The worst days
Worst days for DL 1040
The latest arrival of the period was on 21 February 2026, 5 hours 17 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 21 February 2026 | 5 hours 17 minutes | Carrier |
| 21 July 2026 | 3 hours 26 minutes | Carrier |
| 21 May 2026 | 1 hour 10 minutes | Carrier |
| 28 January 2026 | 1 hour 8 minutes | Carrier |
| 30 November 2025 | 36 minutes | Carrier |
Delay causes
Why DL 1040 runs late
Carrier accounts for 73% of the 1,051 delay minutes carriers reported here, and the remaining four split what is left.
- 73%Carrier
- 21%National Airspace System
- 6%Late-arriving aircraft
The largest share of delay minutes, 73%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 764 of the 1,051 delay minutes reported here. The split is drawn from 1,051 delay minutes reported on DL 1040.
Cancellations sit at 1.95% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 1.1% 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 1,149 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 359 flights under DL 1040 in the data flew AUS to DTW. 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. 359 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 1040
For a booking, read DL 1040 as 93.8% on time with 1.95% cancelled over 359 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- AUS to DTW, every carrier and departure
- DTW to AUS, the return direction
- Delta Air Lines 2736 on the same route80.8%
- Austin-Bergstrom International (AUS) delay statistics
- Detroit Metropolitan Wayne County (DTW) 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
- How to read this site: grades, sample sizes, and honest caveats
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.