Flight profile · Delta Air Lines
DL831
Seattle (SEA) to Austin (AUS) · scheduled 11:15 AM – 5:50 PM
How DL831 performs
677 operations, June 2024 – July 2026.
Source: US DOT Bureau of Transportation Statistics · 677 operations, June 2024 – July 2026 · If DL831 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where DL831 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| DL831 | 77.2% | 1.18% | -7 min | 7.3% | 677 |
| Delta Air Lines on SEA → AUS | 80.9% | 0.65% | -7 min | 6.7% | 2,749 |
| All SEA → AUS flights | 77.1% | 0.62% | -3 min | 5.6% | 6,405 |
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
Why DL831 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for DL831 on SEA → AUS. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies DL831 comes in late, and what that does to the departure.
The aircraft flying DL831 came in 15 or more minutes late on 11% of the departures where its previous flight is known. There are not enough departures in both groups to say how the flight left after a late one and after an on-time one.
Each departure is matched to the flight the same aircraft flew into SEA just before it, using the tail number in the DOT file, 633 of 669 departures in all. A departure is left out when that flight is unknown, was cancelled or diverted, or the aircraft had sat for more than 12 hours. A flight the airline cancelled never left and is not in the count, and one flown by a substitute aircraft is matched to the aircraft that flew it, not to the one first planned.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late |
|---|---|
| DL831 | 11% |
| Network, same turn | 18% |
The schedule leaves a normal turn: enough time to clean and board if the aircraft is on time, little to spare if it is not.
The network row is every flight with a scheduled turn of 45 to 59 minutes. How often DL831’s aircraft landed 15 or more minutes late is lower than the network’s. There are not enough departures in both groups to compare how it left.
More: Which Flight Numbers Pay for a Late Aircraft lists the flight numbers that pass a late aircraft on.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – July 2026
From pushback to gate
When it leaves SEA late, does that still matter by the time it reaches AUS?
DL831 pushes back an average of 10.1 minutes late and reaches the gate at AUS an average of 6.0 minutes late. The 4.1 minutes between those two figures are slack the published schedule already carries, which is why a late pushback on this flight does not reliably become a late arrival. It spends 21.4 minutes on the taxiways at SEA, 2.3 minutes shorter than a typical SEA departure in the same hour.
On arrival at AUS, DL831 spends 14.9 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is 6.6 minutes longer than a typical AUS arrival (8.3 min).
Departure delay is averaged over every pushback and arrival delay over every completed arrival, so the two counts differ by the flights that never reached AUS. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 44,293 departures from SEA scheduled in the clock hour DL831 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at AUS (272,531 flights), not just DL831’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
The hour it leaves SEA
Part of any flight’s record belongs to the clock rather than to the flight. DL831 has one departure time, so this is what that time is worth.
On-time arrival rate. 44,293 departures from SEA are scheduled in the 11 AM–12 PM hour over the period, against 510,205 across the whole day.
DL831 is scheduled out of SEA at 11:15 AM, in the 11 AM–12 PM bank. Departures from SEA in that hour arrive on time 74.7% of the time against 79.1% across the airport’s whole day — the slot alone is worth 4.4 points worse before anything about this particular flight is considered.
The two airport figures cover every departure from SEA to every destination, so they describe the slot rather than this journey — the like-for-like comparison against the route is above. Hours are scheduled local, and a number whose schedule moved between banks inside the period has no single hour and is not described here at all. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026 · Hours below 120 departures are not scored.
Other routes DL831 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| AUS→SEA Austin to Seattle | July 8, 2024 – July 31, 2026 | 353 | 73.5% |
| MCO→BOS Orlando to Boston | January 6, 2025 – March 8, 2025 | 62 | — |
| JFK→LAS New York to Las Vegas | May 7, 2024 – June 6, 2024 | 31 | — |
| SFO→JFK San Francisco to New York | April 15, 2024 – May 6, 2024 | 19 | — |
| MSP→TUS Minneapolis to Tucson | April 9–14, 2024 | 6 | — |
| TUS→MSP Tucson to Minneapolis | April 9–14, 2024 | 6 | — |
| MSP→LAX Minneapolis to Los Angeles | July 1, 2023 – April 8, 2024 | 221 | 86.4% |
| PHX→DTW Phoenix to Detroit | January 8, 2024 – March 9, 2024 | 62 | — |
Because the same number has served different journeys, the statistics above describe only the route DL831 currently operates. Blending them would produce an average of two different flights.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
40 min late
against a median of 7 min early
Percentiles over 677 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – July 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| DL739 | Delta Air Lines | 86.5% | 11 min early | 681 |
| AS502 | Alaska Airlines | 81.6% | 3 min early | 1,073 |
| DL831 this flight | Delta Air Lines | 77.2% | 7 min early | 677 |
| DL848 | Delta Air Lines | 75.7% | 5 min early | 605 |
| AS318 | Alaska Airlines | 70.0% | 3 min late | 646 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. DL831 is placed in the same ordering rather than left out of it; the rows around it are the most punctual departures on the route, not all of them, so this is a comparison and not a rank. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 677 records of DL831 operating SEA → AUS, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
Full methodology · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
Analysis last recomputed