Flight profile · Delta Air Lines
DL503
Atlanta (ATL) to Portland (PDX) · scheduled 4:45 PM – 7:03 PM
How DL503 performs
993 operations, July 2023 – July 2026.
DL503 arrived on time 76.9% of the time, against 79.9% for all ATL → PDX flights, so this departure is 3.0 percentage points worse than the route as a whole. Against Delta Air Lines’ own flights on this route it is 4.0 points worse.
Source: US DOT Bureau of Transportation Statistics · 993 operations, July 2023 – July 2026 · If DL503 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
What stands out
How DL503 compares to other flight numbers, not just to itself.
Which day you fly matters unusually much here, a wider weekday spread than 90% of 1,710 comparable flight numbers.
84.8% on time on a typical Saturday, against 67.6% on a Sunday.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · The one thing about this specific departure that ranks most extreme against every other published flight number, out of everything FlyerIntel checks — shown only when something clears a real statistical bar, not for every flight.
Where DL503 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
Ask for the position of DL503 right now, if receivers on the ground are hearing it. Nothing is requested until you press the button.
Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| DL503 | 76.9% | 0.40% | -3 min | 7.2% | 993 |
| Delta Air Lines on ATL → PDX | 80.9% | 0.79% | -5 min | 4.9% | 3,926 |
| All ATL → PDX flights | 79.9% | 0.76% | -4 min | 5.4% | 4,445 |
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
Why DL503 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 DL503 on ATL → PDX. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies DL503 comes in late, and what that does to the departure.
The aircraft flying DL503 came in 15 or more minutes late on 12% 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 ATL just before it, using the tail number in the DOT file, 925 of 989 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 |
|---|---|
| DL503 | 12% |
| Network, same turn | 23% |
The schedule leaves a long gap on the ground, which gives a late aircraft room to catch up before this flight pushes back.
The network row is every flight with a scheduled turn of 90 minutes to 3 hours. How often DL503’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 July 2023 – July 2026
From pushback to gate
When it leaves ATL late, does that still matter by the time it reaches PDX?
DL503 pushes back an average of 10.8 minutes late and reaches the gate at PDX an average of 7.6 minutes late. The 3.2 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 17.2 minutes on the taxiways at ATL is about what any departure from the airport in that hour spends.
On arrival at PDX, DL503 spends 4.8 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 PDX 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 PDX. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 60,834 departures from ATL scheduled in the clock hour DL503 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at PDX (187,629 flights), not just DL503’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
The hour it leaves ATL
Part of any flight’s record belongs to the clock rather than to the flight. DL503 has one departure time, so this is what that time is worth.
On-time arrival rate. 60,834 departures from ATL are scheduled in the 4 PM–5 PM hour over the period, against 1,012,247 across the whole day.
DL503 is scheduled out of ATL at 4:45 PM, in the 4 PM–5 PM bank. Departures from ATL in that hour arrive on time 73.3% of the time against 78.7% across the airport’s whole day — the slot alone is worth 5.4 points worse before anything about this particular flight is considered.
The two airport figures cover every departure from ATL 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 · July 2023 – July 2026 · Hours below 120 departures are not scored.
By day of week
Does DL503 run worse on particular days?
Saturday is historically the most reliable day and Sunday the least, a gap of 17.2 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Days with fewer than 120 operations are not scored.
Other routes DL503 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 |
|---|---|---|---|
| ATL→TYS Atlanta to Knoxville/Maryville | February 16, 2025 | 1 | — |
| TYS→ATL Knoxville/Maryville to Atlanta | February 16, 2025 | 1 | — |
| MSP→LAS Minneapolis to Las Vegas | January 9–10, 2025 | 2 | — |
| PDX→ATL Portland to Atlanta | September 25, 2023 – March 6, 2024 | 38 | — |
| FLL→ATL Fort Lauderdale to Atlanta | January 12, 2024 | 1 | — |
| LAS→ATL Las Vegas to Atlanta | January 8, 2024 | 1 | — |
| BDL→ATL Hartford to Atlanta | October 28, 2023 – November 4, 2023 | 6 | — |
| ATL→BDL Atlanta to Hartford | October 29–30, 2023 | 2 | — |
| RSW→ATL Fort Myers to Atlanta | October 10–25, 2023 | 8 | — |
Because the same number has served different journeys, the statistics above describe only the route DL503 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.
44 min late
against a median of 3 min early
Percentiles over 993 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Data and methodology
Calculated by FlyerIntel from 993 records of DL503 operating ATL → PDX, 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