Flight number record

AS 443

Alaska Airlines · Philadelphia to Seattle

Route: PHL → SEA
Departs: 18:52
Flights: 332
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 443, check with Alaska Airlines.

AS 443 draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 55 minutes behind schedule. Build slack into anything you connect to. That rests on 332 flights, with a median arrival 5 minutes late.

The national on-time rate over the same period is 77.6%, so AS 443 runs 17 points behind the country as a whole. Across a thousand flights that is about 168 extra late arrivals.

On time

60.8%

Arrivals under 15 minutes late, of 324 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

2.11%

National rate is 1.81%

1 hour+ late

12.7%

National rate is 8.1%

These figures cover 332 flights between July 2025 and June 2026. Beyond the headline rate, 12.7% 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 443 flies

AS 443 flies PHL to SEA without a single fixed slot. Its most common scheduled departure was 18:52, used on 49 of 332 flights, with 19:06 (36 flights) and 18:47 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 18:5249 flights14.8%
Departs 19:0636 flights10.8%
Departs 18:4735 flights10.5%

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 18:52 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and AS 443 runs 7 points worse at 60.8%. 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 443 next to PHL to SEA

Every carrier on PHL to SEA combined arrived on time 69.5% of the time across 1,327 flights, so AS 443 is 9 points behind it. Alaska flew 656 flights on the same city pair under all its flight numbers, including this one, and those ran 65.6% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight trails by 18 points.

AS 443 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 443thin sample	332	60.8%	54 min	2.11%	D
All Alaska Airlines on PHL–SEA	656	65.6%	54 min	1.52%	C
All carriers on PHL–SEA	1,327	69.5%	52 min	1.81%	C
Alaska Airlines, whole network	293,372	79.1%	52 min	1.28%	B

Across the year

AS 443 quarter by quarter

AS 443 did not run the same all year. Its best quarter was Apr–Jun 2026 at 81.4% on time and its weakest Jul–Sep 2025 at 48.3%, a swing of 33 points on roughly 83 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 202591 flights48.3%
Oct–Dec 202590 flights55.1%
Jan–Mar 202689 flights65.5%
Apr–Jun 202662 flights81.4%

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

By weekday, AS 443 did best on Tuesday at 75.5% on time and worst on Thursday at 50.0%. Each day rests on about 47 flights, so a gap of 26 points is worth noticing but could still narrow in another year.

Delay causes

Why AS 443 runs late

One category carries most of the weight here. National Airspace System accounts for 44% of the 6,838 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

National Airspace System
44%
Late-arriving aircraft
35%
Carrier
19%
Extreme weather
2%
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 6,838 reported delay minutes here, that single category outweighs weather by 18 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 6,838 delay minutes reported on AS 443.

Cancellations sit at 2.11% against a national 1.81%, which is ordinary. Diversions add another 0.30%.

Connections and routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 12.7% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

At 2,379 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 DFW to SEA (28), but none flew often enough under AS 443 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to PHL to SEA only.

One caution: this is a thin sample. 332 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 443

For a booking, AS 443 is a flight to put a long connection behind. 12.7% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.

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