Flight profile · Delta Air Lines
DL506
Seattle (SEA) to Miami (MIA) · scheduled 8:00 AM – 4:05 PM
How DL506 performs
621 operations, December 2024 – August 2026.
Between its first and last recorded date on SEA → MIA, DL506 averaged about one operation a day or more (621 in 621 days, cancelled ones included).
DL506 arrived on time 79.6% of the time, against 78.3% for all SEA → MIA flights, so this departure is 1.3 percentage points better than the route as a whole.
Source: US DOT Bureau of Transportation Statistics · 621 operations, December 2024 – August 2026 · If DL506 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where DL506 is right now
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| DL506 | 79.6% | 0.97% | -8 min | 4.7% | 621 |
| Delta Air Lines on SEA → MIA | 79.6% | 0.97% | -8 min | 4.7% | 621 |
| All SEA → MIA flights | 78.3% | 0.96% | -7 min | 5.8% | 3,137 |
DL506 cancelled 6 of 621 operations (0.97%), close to the 0.96% for SEA → MIA.
Source: FlyerIntel analysis of US DOT BTS data · December 2024 – August 2026
Why DL506 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
weather severe enough to stop this flight specifically
the inbound aircraft was late, so this flight started late
Share of the delay minutes US DOT attributed to each cause for DL506 on SEA → MIA. Only delays of 15 minutes or more are attributed. What the five causes mean
Source: US DOT Bureau of Transportation Statistics · Data covering December 2024 – August 2026
Does a late aircraft delay this flight?
How often the plane that flies DL506 comes in late, and what that does to the departure.
DL506 is usually the aircraft’s first flight of the day: the schedule gives it a median of 7.2 hours on the ground at SEA, so its “inbound” is mostly the aircraft’s arrival the evening before.
The aircraft flying DL506 came in 15 or more minutes late on 20% 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: 554 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 |
|---|---|
| DL506 | 20% |
| Network, same turn | 29% |
A night on the ground absorbs most of a late arrival, so a late inbound matters far less here than on a same-day turn.
The network row is every flight with a scheduled turn of 6 hours or more, usually overnight. How often DL506’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.
Source: US DOT Bureau of Transportation Statistics · Data covering December 2024 – August 2026
From pushback to gate
When it leaves SEA late, does that still matter by the time it reaches MIA?
DL506 pushes back an average of 4.3 minutes late and reaches the gate at MIA an average of 0.9 minutes late. The 3.3 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 24.2 minutes on the taxiways at SEA is about what any departure from the airport in that hour spends.
On arrival at MIA, DL506 spends 12.8 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 3.0 minutes longer than a typical MIA arrival (9.7 min).
Taxi-out is gate to wheels up and sits inside the scheduled block; the hourly comparison is 34,488 SEA departures. Taxi-in is landing to gate, set against 349,140 arrivals at MIA. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · December 2024 – August 2026
The hour it leaves SEA
DL506 has one departure time, 8:00 AM, so this is what that hour at SEA is worth.
On-time arrival rate. 34,488 departures from SEA are scheduled in the 8 AM–9 AM hour over the period, against 526,113 across the whole day.
DL506 is scheduled out of SEA at 8:00 AM, in the 8 AM–9 AM bank. Departures from SEA in that hour arrive on time 83.6% of the time against 78.9% across the airport’s whole day — the slot alone is worth 4.7 points better before anything about this particular flight is considered.
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 · December 2024 – August 2026 · Hours below 120 departures are not scored.
Other routes DL506 has flown
Carriers reassign flight numbers. DL506 also served these 12 other city pairs in the period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| MIA→SEA Miami to Seattle | December 19, 2024 – August 31, 2026 | 422 | 63.3% |
| LAS→ATL Las Vegas to Atlanta | October 7, 2024 – December 18, 2024 | 72 | — |
| MCO→JFK Orlando to New York | September 9, 2024 – October 6, 2024 | 28 | — |
| SAN→ATL San Diego to Atlanta | July 8, 2024 – September 8, 2024 | 31 | — |
| SAT→DTW San Antonio to Detroit | June 7, 2024 – July 7, 2024 | 21 | — |
| LGA→ATL New York to Atlanta | July 5, 2023 – June 6, 2024 | 162 | 89.9% |
| ATL→LEX Atlanta to Lexington | May 11, 2024 – June 1, 2024 | 5 | — |
| LGA→BOS New York to Boston | January 8, 2024 – May 19, 2024 | 55 | — |
| SFO→DTW San Francisco to Detroit | April 9, 2024 – May 6, 2024 | 28 | — |
| SLC→BOS Salt Lake City to Boston | March 10, 2024 – April 8, 2024 | 30 | — |
| ATL→TYS Atlanta to Knoxville/Maryville | December 23, 2023 | 1 | — |
| TYS→ATL Knoxville/Maryville to Atlanta | December 23, 2023 | 1 | — |
The figures above describe only SEA → MIA, the route DL506 flies now.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
32 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 December 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 |
|---|---|---|---|---|
| DL506 this flight | Delta Air Lines | 79.6% | 8 min early | 621 |
| AA1471 | American Airlines | 76.9% | 6 min early | 646 |
| AS305 | Alaska Airlines | 76.6% | 6 min early | 1,033 |
Among all 3 departures on this route with at least 600 operations, DL506 has the highest on-time rate. 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 DL506 operating SEA → MIA, 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