Flight profile · Alaska Airlines
AS517
Fort Lauderdale (FLL) to Seattle (SEA) · scheduled 10:00 AM – 10:00 PM
How AS517 performs
1,047 operations, July 2023 – July 2026.
AS517 arrived on time 68.8% of the time, against 72.7% for all FLL → SEA flights, so this departure is 3.9 percentage points worse than the route as a whole. Against Alaska Airlines’ own flights on this route it is 1.9 points worse.
Source: US DOT Bureau of Transportation Statistics · 1,047 operations, July 2023 – July 2026 · If AS517 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 AS517 compares to other flight numbers, not just to itself.
Which day you fly matters unusually much here, a wider weekday spread than 98% of 1,710 comparable flight numbers.
79.5% on time on a typical Tuesday, against 56.8% 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 AS517 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 AS517 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 |
|---|---|---|---|---|---|
| AS517 | 68.8% | 2.10% | 0 min | 7.9% | 1,047 |
| Alaska Airlines on FLL → SEA | 70.7% | 2.45% | 0 min | 6.9% | 1,591 |
| All FLL → SEA flights | 72.7% | 1.92% | -2 min | 7.5% | 2,714 |
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
Why AS517 runs late
Where US DOT attributed the delay minutes on this flight.
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
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 AS517 on FLL → SEA. 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 AS517 comes in late, and what that does to the departure.
When the aircraft came in 15 or more minutes late, AS517 pushed back an average of 49 minutes late; when it came in on time or early, an average of 5 minutes late.
Each departure is matched to the flight the same aircraft flew into FLL just before it, using the tail number in the DOT file, 1,006 of 1,027 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 | Left 15+ late after a late inbound | Left 15+ late after an on-time inbound |
|---|---|---|---|
| AS517 | 21% | 80% | 12% |
| Network, same turn | 17% | 68% | 9% |
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 AS517’s aircraft landed 15 or more minutes late is higher than the network’s and, once the aircraft was late, how often AS517 left 15 or more minutes late is higher than the network’s.
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 FLL late, does that still matter by the time it reaches SEA?
AS517 pushes back an average of 15.3 minutes late and reaches the gate at SEA an average of 9.6 minutes late. The 5.7 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 23.5 minutes on the taxiways at FLL, 5.8 minutes longer than a typical FLL departure in the same hour.
On arrival at SEA, AS517 spends 13.0 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 1.1 minutes longer than a typical SEA arrival (11.9 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 SEA. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 11,039 departures from FLL scheduled in the clock hour AS517 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at SEA (510,187 flights), not just AS517’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
The hour it leaves FLL
Part of any flight’s record belongs to the clock rather than to the flight. AS517 has one departure time, so this is what that time is worth.
On-time arrival rate. 11,039 departures from FLL are scheduled in the 10 AM–11 AM hour over the period, against 278,691 across the whole day.
AS517 is scheduled out of FLL at 10:00 AM, in the 10 AM–11 AM bank. Departures from FLL in that hour arrive on time 81.5% of the time against 72.6% across the airport’s whole day — the slot alone is worth 8.9 points better before anything about this particular flight is considered.
The two airport figures cover every departure from FLL 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 AS517 run worse on particular days?
Tuesday is historically the most reliable day and Sunday the least, a gap of 22.7 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 AS517 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 |
|---|---|---|---|
| SEA→FLL Seattle to Fort Lauderdale | May 13, 2026 – June 9, 2026 | 28 | — |
Because the same number has served different journeys, the statistics above describe only the route AS517 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.
52 min late
against a median of 0 min early
Percentiles over 1,047 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 1,047 records of AS517 operating FLL → SEA, 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