Flight number record

AS 517

Alaska Airlines · Fort Lauderdale to Seattle

Route: FLL → SEA
Departs: 17:52
Flights: 317
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 517, check with Alaska Airlines.

AS 517 draws a D. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about 55 minutes behind schedule. Build slack into anything you connect to. That rests on 317 flights, with a median arrival 5 minutes late.

The national on-time rate over the same period is 77.6%, so AS 517 runs 14 points behind the country as a whole. Across a thousand flights that is about 135 extra late arrivals.

On time

64.1%

Arrivals under 15 minutes late, of 309 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

1.26%

National rate is 1.81%

1 hour+ late

8.4%

National rate is 8.1%

These figures cover 317 flights between July 2025 and June 2026. Beyond the headline rate, 8.4% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Schedule

When AS 517 flies

AS 517 flies FLL to SEA without a single fixed slot. Its most common scheduled departure was 17:52, used on 50 of 317 flights, with 18:23 (47 flights) and 17:54 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:5250 flights15.8%
Departs 18:2347 flights14.8%
Departs 17:5435 flights11.0%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 17:52 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and AS 517 runs 4 points worse at 64.1%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

AS 517 next to FLL to SEA

Every carrier on FLL to SEA combined arrived on time 69.7% of the time across 826 flights, so AS 517 is 6 points behind it. Across its whole network Alaska Airlines managed 79.1%, which this flight trails by 15 points.

AS 517 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 517thin sample	317	64.1%	54 min	1.26%	D
All Alaska Airlines on FLL–SEA	462	66.5%	56 min	1.30%	C
All carriers on FLL–SEA	826	69.7%	65 min	1.45%	C
Alaska Airlines, whole network	293,372	79.1%	52 min	1.28%	B

Across the year

AS 517 quarter by quarter

AS 517 did not run the same all year. Its best quarter was Apr–Jun 2026 at 80.9% on time and its weakest Jan–Mar 2026 at 48.8%, a swing of 32 points on roughly 79 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Jul–Sep 202592 flights60.4%
Oct–Dec 202589 flights58.1%
Jan–Mar 202645 flights48.8%
Apr–Jun 202691 flights80.9%

Scale runs 40% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, AS 517 did best on Tuesday at 74.4% on time and worst on Sunday at 46.7%. Each day rests on about 45 flights, so a gap of 28 points is worth noticing but could still narrow in another year.

Delay causes

Why AS 517 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 5,996 reported delay minutes.

Late-arriving aircraft
35%
National Airspace System
33%
Carrier
27%
Extreme weather
5%
Security
0%

35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 5,996 reported delay minutes here, that single category outweighs weather by 7 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 5,996 delay minutes reported on AS 517.

Cancellations sit at 1.26% against a national 1.81%, which is ordinary. Diversions add another 1.26%.

Connections and routes

What a delay on this flight costs

8.4% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 55 minutes, which a normal layover absorbs.

At 2,717 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The same number turns up on one other city pair in the data, including SEA to FLL (28), but none flew often enough under AS 517 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to FLL to SEA only.

One caution: this is a thin sample. 317 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking AS 517

For a booking, AS 517 is one of the weaker ways to fly FLL to SEA: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

Where to go next

A flight number here means Alaska Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures