Flight number record
AS 477
Alaska Airlines · Seattle to Newark
- Route
- SEA → EWR
- Departs
- 10:05
- Flights
- 330
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 477, check with Alaska Airlines.
AS 477 lands a B, about a point worse than the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 330 flights, with a median arrival 6 minutes early.
Key figures
On time
76.4%
Arrivals under 15 minutes late, of 318 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
2.73%
National rate is 1.89%
1 hour+ late
9.4%
National rate is 8.3%
These figures cover 330 flights between September 2025 and August 2026. Beyond the headline rate, 9.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When AS 477 flies
AS 477 flies SEA to EWR without a single fixed slot. Its most common scheduled departure was 10:05, used on 97 of 330 flights, with 10:09 (70 flights) and 10:00 (48 flights) next.
- Departs 10:0597 flights29.4%
- Departs 10:0970 flights21.2%
- Departs 10:0048 flights14.5%
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 10:05 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and AS 477 runs 8 points worse at 76.4%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
AS 477 next to SEA to EWR
Every carrier on SEA to EWR combined arrived on time 83.4% of the time across 2,264 flights, so AS 477 is 7 points behind it. Alaska flew 1,274 flights on the same city pair under all its flight numbers, including this one, and those ran 82.7% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight trails by 3 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 477thin sample | 330 | 76.4% | 58 min | 2.73% | B |
| All Alaska Airlines on SEA–EWR | 1,274 | 82.7% | 54 min | 2.28% | B |
| All carriers on SEA–EWR | 2,264 | 83.4% | 67 min | 2.12% | B |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 477 quarter by quarter
AS 477 did not run the same all year. Its best quarter was Apr–Jun 2026 at 88.4% on time and its weakest Oct–Dec 2025 at 63.2%, a swing of 25 points on roughly 66 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 flights80.0%
- Oct–Dec 202591 flights63.2%
- Jan–Mar 202690 flights80.5%
- Apr–Jun 202670 flights88.4%
- Jul–Sep 202649 flights73.3%
Scale runs 55% to 95%.
By weekday, AS 477 did best on Wednesday at 88.6% on time and worst on Friday at 66.7%. Each day rests on about 47 flights, so a gap of 22 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 477 runs when it is late
AS 477 often beats the schedule: 105 of 318 completed flights, 33%, arrived 15 minutes or more early. The 75 late arrivals split 31 under half an hour, 14 between 30 and 60 minutes, and 30 an hour or more.
- 15+ min early105 flights33.0%
- Within 15 min138 flights43.4%
- 15–29 min late31 flights9.7%
- 30–59 min late14 flights4.4%
- 1–2 hours late21 flights6.6%
- 2+ hours late9 flights2.8%
Scale runs 0% to 100%.
Share of 318 completed flights by arrival against schedule.
A late pushback is often recovered here: of 97 departures that left 15 minutes late or more, 32 still arrived on time. 10 flights left on time and still arrived late.
The worst days
Worst days for AS 477
The latest arrival of the period was on 9 November 2025, 3 hours 27 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 9 November 2025 | 3 hours 27 minutes | National Airspace System |
| 14 December 2025 | 3 hours 15 minutes | National Airspace System |
| 3 August 2026 | 2 hours 57 minutes | National Airspace System |
| 8 August 2026 | 2 hours 47 minutes | National Airspace System |
| 9 July 2026 | 2 hours 43 minutes | National Airspace System |
Delay causes
Why AS 477 runs late
National Airspace System accounts for 57% of the 4,379 delay minutes carriers reported here, and the remaining four split what is left.
- 57%National Airspace System
- 20%Carrier
- 14%Late-arriving aircraft
- 9%Extreme weather
- 0%Security
57% 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 2,481 minutes out of 4,379, against a national NAS share of 21%. The split is drawn from 4,379 delay minutes reported on AS 477.
Cancellations run at 2.73%, against 1.89% nationally. That is roughly 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
9.4% 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 2,402 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 BOS to SEA (8), but none flew often enough under AS 477 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to EWR only.
One caution: this is a thin sample. 330 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 477
For a booking, the cancellation rate is the figure to plan around on AS 477: 2.73% of its 330 scheduled flights did not operate. A late arrival costs about an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- SEA to EWR, every carrier and departure
- EWR to SEA, the return direction
- Seattle-Tacoma International (SEA) delay statistics
- Newark Liberty International (EWR) 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
- What a cancellation rate actually tells you (and what it hides)
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.