Flight number record
AS 443
Alaska Airlines · Philadelphia to Seattle
- Route
- PHL → SEA
- Departs
- 16:26
- Flights
- 333
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 443, check with Alaska Airlines.
AS 443 draws a D. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 50 minutes behind schedule. Build slack into anything you connect to. That rests on 333 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.3%, so AS 443 runs 13 points behind the country as a whole. Across a thousand flights that is about 134 extra late arrivals.
Key figures
On time
63.9%
Arrivals under 15 minutes late, of 324 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
2.70%
National rate is 1.89%
1 hour+ late
10.2%
National rate is 8.3%
These figures cover 333 flights between September 2025 and August 2026. Beyond the headline rate, 10.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When AS 443 flies
AS 443 flies PHL to SEA without a single fixed slot. Its most common scheduled departure was 16:26, used on 69 of 333 flights, with 19:06 (36 flights) and 18:47 (35 flights) next.
- Departs 16:2669 flights20.7%
- Departs 19:0636 flights10.8%
- Departs 18:4735 flights10.5%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 16:26 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and AS 443 runs 8 points worse at 63.9%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
AS 443 next to PHL to SEA
Every carrier on PHL to SEA combined arrived on time 69.4% of the time across 1,431 flights, so AS 443 is 6 points behind it. Alaska flew 657 flights on the same city pair under all its flight numbers, including this one, and those ran 68.0% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight trails by 16 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 443thin sample | 333 | 63.9% | 52 min | 2.70% | D |
| All Alaska Airlines on PHL–SEA | 657 | 68.0% | 51 min | 1.67% | C |
| All carriers on PHL–SEA | 1,431 | 69.4% | 54 min | 1.82% | C |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | 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 Oct–Dec 2025 at 55.1%, a swing of 26 points on roughly 67 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 202530 flights63.3%
- Oct–Dec 202590 flights55.1%
- Jan–Mar 202689 flights65.5%
- Apr–Jun 202662 flights81.4%
- Jul–Sep 202662 flights57.6%
Scale runs 45% to 85%.
By weekday, AS 443 did best on Tuesday at 68.8% on time and worst on Thursday at 56.8%. Each day rests on about 48 flights, so a gap of 12 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 443 runs when it is late
The 117 late arrivals split 40 under half an hour, 44 between 30 and 60 minutes, and 33 an hour or more.
- 15+ min early60 flights18.5%
- Within 15 min147 flights45.4%
- 15–29 min late40 flights12.3%
- 30–59 min late44 flights13.6%
- 1–2 hours late26 flights8.0%
- 2+ hours late7 flights2.2%
Scale runs 0% to 100%.
Share of 324 completed flights by arrival against schedule.
24 of 84 late departures made up the time and arrived on time, 29% of them. In the other direction, 57 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SEA.
The worst days
Worst days for AS 443
The latest arrival of the period was on 28 July 2026, 4 hours 36 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The five worst days are spread across July, August, October and December, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 July 2026 | 4 hours 36 minutes | National Airspace System |
| 20 August 2026 | 3 hours 23 minutes | Carrier |
| 27 August 2026 | 2 hours 38 minutes | Late-arriving aircraft |
| 1 October 2025 | 2 hours 36 minutes | Late-arriving aircraft |
| 26 December 2025 | 2 hours 29 minutes | National Airspace System |
Delay causes
Why AS 443 runs late
National Airspace System accounts for 49% of the 6,124 delay minutes carriers reported here, and the remaining four split what is left.
- 49%National Airspace System
- 28%Late-arriving aircraft
- 21%Carrier
- 1%Extreme weather
- 0%Security
49% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,028 minutes out of 6,124, against a national NAS share of 21%. The split is drawn from 6,124 delay minutes reported on AS 443.
Cancellations run at 2.70%, against 1.89% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and routes
What a delay on this flight costs
10.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection 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. 333 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, the cancellation rate is the figure to plan around on AS 443: 2.70% of its 333 scheduled flights did not operate. A late arrival costs roughly 50 minutes, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- PHL to SEA, every carrier and departure
- SEA to PHL, the return direction
- Philadelphia International (PHL) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Alaska Airlines on-time record
- Every Alaska Airlines flight number with a record
- The most and least reliable flight numbers in the US
- How often a connection fails at the major US hubs
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.