Flight profile · Delta Air Lines
DL2851
Seattle (SEA) to Denver (DEN) · scheduled 7:55 PM – 11:28 PM
How DL2851 performs
621 operations, June 2024 – August 2026.
Between its first and last recorded date on SEA → DEN, DL2851 averaged about 5 operations a week (621 in 816 days, cancelled ones included).
DL2851 arrived on time 75.1% of the time, against 77.5% for all SEA → DEN flights, so this departure is 2.4 percentage points worse than the route as a whole.
Source: US DOT Bureau of Transportation Statistics · 621 operations, June 2024 – August 2026 · If DL2851 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where DL2851 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 |
|---|---|---|---|---|---|
| DL2851 | 75.1% | 0.97% | -8 min | 7.8% | 621 |
| Delta Air Lines on SEA → DEN | 74.9% | 0.64% | -5 min | 8.0% | 2,967 |
| All SEA → DEN flights | 77.5% | 0.73% | -5 min | 6.8% | 20,943 |
DL2851 cancelled 6 of 621 operations (0.97%), close to the 0.73% for SEA → DEN.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – August 2026
Why DL2851 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
Share of the delay minutes US DOT attributed to each cause for DL2851 on SEA → DEN. Only delays of 15 minutes or more are attributed. What the five causes mean
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – August 2026
Does a late aircraft delay this flight?
How often the plane that flies DL2851 comes in late, and what that does to the departure.
The aircraft flying DL2851 came in 15 or more minutes late on 15% 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.
Matched by tail number to the aircraft’s previous flight into SEA: 590 of 615 departures. Unknown, cancelled or diverted inbounds and gaps over 12 hours are left out.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late |
|---|---|
| DL2851 | 15% |
| Network, same turn | 17% |
66 scheduled minutes is enough to clean and board when the aircraft is on time, with little to spare when it is not.
The network row is every flight with a scheduled turn of 60 to 89 minutes. How often DL2851’s aircraft landed 15 or more minutes late is about the same as the network’s. There are not enough departures in both groups to compare how it left.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – August 2026
From pushback to gate
When it leaves SEA late, does that still matter by the time it reaches DEN?
DL2851 pushes back an average of 12.0 minutes late and reaches the gate at DEN an average of 6.6 minutes late. The 5.4 minutes between those two figures are slack the published schedule already carries, so a late pushback is partly, not fully, made up before the gate. Its 20.0 minutes on the taxiways at SEA is about what any departure from the airport in that hour spends.
On arrival at DEN, DL2851 spends 12.6 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 2.8 minutes longer than a typical DEN arrival (9.8 min).
Taxi-out is gate to wheels up and sits inside the scheduled block; the hourly comparison is 30,675 SEA departures. Taxi-in is landing to gate, set against 991,579 arrivals at DEN. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – August 2026
The hour it leaves SEA
DL2851 has one departure time, 7:55 PM, so this is what that hour at SEA is worth.
On-time arrival rate. 30,675 departures from SEA are scheduled in the 7 PM–8 PM hour over the period, against 526,113 across the whole day.
DL2851 is scheduled out of SEA at 7:55 PM, in the 7 PM–8 PM bank. Departures from SEA in that hour arrive on time 77.2% of the time against 78.9% across the airport’s whole day, so the hour DL2851 leaves in is an ordinary one for SEA and explains nothing about its record either way.
Both airport figures cover every destination from SEA, so they describe the slot, not this journey; the route comparison is above. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – August 2026 · Hours below 120 departures are not scored.
Other routes DL2851 has flown
Carriers reassign flight numbers. DL2851 also served these 7 other city pairs in the period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| ATL→JAX Atlanta to Jacksonville | January 15, 2024 – May 6, 2024 | 73 | — |
| BTV→ATL Burlington to Atlanta | December 16, 2023 – January 7, 2024 | 23 | — |
| IND→DTW Indianapolis to Detroit | October 9, 2023 – December 15, 2023 | 59 | — |
| DTW→IND Detroit to Indianapolis | October 9, 2023 – December 15, 2023 | 57 | — |
| IND→ATL Indianapolis to Atlanta | September 5, 2023 – October 8, 2023 | 34 | — |
| ATL→CAE Atlanta to Columbia | July 5, 2023 – September 4, 2023 | 43 | — |
| PNS→ATL Pensacola to Atlanta | July 1–8, 2023 | 2 | — |
The figures above describe only SEA → DEN, the route DL2851 flies now.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
47 min late
against a median of 8 min early
Percentiles over 621 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – August 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| AS682 | Alaska Airlines | 86.8% | 8 min early | 966 |
| UA757 | United Airlines | 83.9% | 9 min early | 1,158 |
| DL2851 this flight | Delta Air Lines | 75.1% | 8 min early | 621 |
| AS642 | Alaska Airlines | 75.0% | 2 min early | 688 |
| F93406 | Frontier Airlines | 74.8% | 3 min early | 685 |
| AS620 | Alaska Airlines | 73.1% | 2 min early | 731 |
Among all 6 departures on this route with at least 600 operations, DL2851 has the 3rd highest on-time rate, 11.7 points behind the best. Every departure here has at least 600 operations; the other rows are the most punctual on the route, not all of them.
Data and methodology
Calculated by FlyerIntel from 621 records of DL2851 operating SEA → DEN, 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 reported separately, not in the on-time rate.
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