Flight profile · Delta Air Lines
DL820
Salt Lake City (SLC) to Washington (DCA) · scheduled 9:55 AM – 4:00 PM
How DL820 performs
784 operations, June 2024 – July 2026.
DL820 arrived on time 83.3% of the time, against 85.0% for all SLC → DCA flights, so this departure is 1.7 percentage points worse than the route as a whole. Against Delta Air Lines’ own flights on this route it is 1.7 points worse.
Source: US DOT Bureau of Transportation Statistics · 784 operations, June 2024 – July 2026 · If DL820 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where DL820 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 |
|---|---|---|---|---|---|
| DL820 | 83.3% | 1.15% | -6 min | 3.0% | 784 |
| Delta Air Lines on SLC → DCA | 85.0% | 0.80% | -8 min | 2.9% | 1,126 |
| All SLC → DCA flights | 85.0% | 0.80% | -8 min | 2.9% | 1,126 |
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
Why DL820 runs late
Where US DOT attributed the delay minutes on this flight.
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s 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 DL820 on SLC → DCA. 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 DL820 comes in late, and what that does to the departure.
The aircraft flying DL820 came in 15 or more minutes late on 7% 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 SLC just before it, using the tail number in the DOT file, 690 of 775 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 |
|---|---|
| DL820 | 7% |
| Network, same turn | 17% |
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 60 to 89 minutes. How often DL820’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 SLC late, does that still matter by the time it reaches DCA?
DL820 pushes back an average of 4.3 minutes late and reaches the gate at DCA an average of 0.6 minutes early. The 4.9 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. Its 19.4 minutes on the taxiways at SLC is about what any departure from the airport in that hour spends.
On arrival at DCA, DL820 spends 6.9 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 about what any arrival at DCA spends on the ground before reaching the gate.
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 DCA. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 26,936 departures from SLC scheduled in the clock hour DL820 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at DCA (435,126 flights), not just DL820’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · June 2024 – July 2026
The hour it leaves SLC
Part of any flight’s record belongs to the clock rather than to the flight. DL820 has one departure time, so this is what that time is worth.
On-time arrival rate. 26,936 departures from SLC are scheduled in the 9 AM–10 AM hour over the period, against 355,300 across the whole day.
DL820 is scheduled out of SLC at 9:55 AM, in the 9 AM–10 AM bank. Departures from SLC in that hour arrive on time 88.0% of the time against 84.0% across the airport’s whole day — the slot alone is worth 4.0 points better before anything about this particular flight is considered.
The two airport figures cover every departure from SLC 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 DL820 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 |
|---|---|---|---|
| DCA→SLC Washington to Salt Lake City | June 7, 2024 – July 31, 2026 | 783 | 76.8% |
| SFO→JFK San Francisco to New York | June 6, 2024 | 1 | — |
| LGA→MCO New York to Orlando | September 6, 2023 – June 1, 2024 | 33 | — |
| MSP→ATL Minneapolis to Atlanta | April 11, 2024 – May 6, 2024 | 16 | — |
| ATL→BZN Atlanta to Bozeman | March 10, 2024 – April 8, 2024 | 30 | — |
| BZN→ATL Bozeman to Atlanta | March 10, 2024 – April 8, 2024 | 30 | — |
| SAN→SLC San Diego to Salt Lake City | January 8, 2024 – March 9, 2024 | 62 | — |
| MCO→LGA Orlando to New York | September 5, 2023 – January 7, 2024 | 84 | — |
| MSP→SEA Minneapolis to Seattle | November 5, 2023 – December 15, 2023 | 38 | — |
| ATL→SAV Atlanta to Savannah | December 4, 2023 | 1 | — |
| ATL→SRQ Atlanta to Sarasota/Bradenton | July 9–31, 2023 | 23 | — |
| SRQ→ATL Sarasota/Bradenton to Atlanta | July 9–31, 2023 | 23 | — |
| BOS→CVG Boston to Cincinnati / Covington | July 1–8, 2023 | 6 | — |
| CVG→BOS Cincinnati / Covington to Boston | July 1–8, 2023 | 6 | — |
| LAS→LAX Las Vegas to Los Angeles | July 5, 2023 | 1 | — |
| LAX→LAS Los Angeles to Las Vegas | July 5, 2023 | 1 | — |
Because the same number has served different journeys, the statistics above describe only the route DL820 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.
25 min late
against a median of 6 min early
Percentiles over 784 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering June 2024 – July 2026
Data and methodology
Calculated by FlyerIntel from 784 records of DL820 operating SLC → DCA, 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