Flight number record
AS 505
Alaska Airlines · Seattle to Los Angeles
- Route
- SEA → LAX
- Departs
- 06:03
- Flights
- 339
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 505, check with Alaska Airlines.
AS 505 lands a B+, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about 40 minutes on average. That rests on 339 flights, with a median arrival 3 minutes early.
Set against the rest of the country, AS 505's record is 6 points better than the US average of 77.3%. That gap is worth roughly 55 fewer late arrivals for every thousand flights.
Key figures
On time
82.8%
Arrivals under 15 minutes late, of 337 completed flights
Avg delay
41 min
Across delayed arrivals only, not all flights
Cancelled
0.29%
National rate is 1.89%
1 hour+ late
2.7%
National rate is 8.3%
These figures cover 339 flights between September 2025 and August 2026. The median arrival is 3 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Schedule
When AS 505 flies
AS 505 flies SEA to LAX without a single fixed slot. Its most common scheduled departure was 06:03, used on 70 of 339 flights, with 09:00 (50 flights) and 10:59 (48 flights) next.
- Departs 06:0370 flights20.6%
- Departs 09:0050 flights14.7%
- Departs 10:5948 flights14.2%
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 06:03 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and AS 505 runs 7 points worse at 82.8%. 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 505 next to SEA to LAX
Every carrier on SEA to LAX combined arrived on time 82.0% of the time across 7,536 flights, so AS 505 is about level with it. Alaska flew 3,293 flights on the same city pair under all its flight numbers, including this one, and those ran 80.4% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight beats by 3 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 505thin sample | 339 | 82.8% | 41 min | 0.29% | B+ |
| All Alaska Airlines on SEA–LAX | 3,293 | 80.4% | 42 min | 0.91% | B+ |
| All carriers on SEA–LAX | 7,536 | 82.0% | 59 min | 0.81% | B+ |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 505 quarter by quarter
AS 505 did not run the same all year. Its best quarter was Apr–Jun 2026 at 90.5% on time and its weakest Jul–Sep 2026 at 77.0%, a swing of 14 points on roughly 68 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 flights90.0%
- Oct–Dec 202573 flights80.8%
- Jan–Mar 202690 flights78.7%
- Apr–Jun 202684 flights90.5%
- Jul–Sep 202662 flights77.0%
Scale runs 70% to 95%.
By weekday, AS 505 did best on Monday at 92.5% on time and worst on Wednesday at 72.7%. Each day rests on about 48 flights, so a gap of 20 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 505 runs when it is late
The 58 late arrivals split 28 under half an hour, 21 between 30 and 60 minutes, and 9 an hour or more.
- 15+ min early79 flights23.4%
- Within 15 min200 flights59.3%
- 15–29 min late28 flights8.3%
- 30–59 min late21 flights6.2%
- 1–2 hours late7 flights2.1%
- 2+ hours late2 flights0.6%
Scale runs 0% to 100%.
Share of 337 completed flights by arrival against schedule.
12 of 49 late departures made up the time and arrived on time, 24% of them. In the other direction, 21 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 LAX.
The worst days
Worst days for AS 505
The latest arrival of the period was on 13 March 2026, 3 hours 29 minutes behind schedule; most of its delay minutes were filed as extreme weather. On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 March 2026 | 3 hours 29 minutes | Extreme weather |
| 27 December 2025 | 2 hours 1 minute | Late-arriving aircraft |
| 13 July 2026 | 1 hour 29 minutes | Carrier |
| 2 December 2025 | 1 hour 27 minutes | Late-arriving aircraft |
| 30 January 2026 | 1 hour 20 minutes | Late-arriving aircraft |
Delay causes
Why AS 505 runs late
Carrier accounts for 43% of the 2,356 delay minutes carriers reported here, and the remaining four split what is left.
- 43%Carrier
- 32%National Airspace System
- 18%Late-arriving aircraft
- 7%Extreme weather
The largest share of delay minutes, 43%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,011 of the 2,356 delay minutes reported here. The split is drawn from 2,356 delay minutes reported on AS 505.
Cancellations are rare at 0.29%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 2.7% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 954 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
Every one of the 339 flights under AS 505 in the data flew SEA to LAX. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 339 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 505
For a booking, read AS 505 as 82.8% on time with 0.29% cancelled over 339 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SEA to LAX, every carrier and departure
- LAX to SEA, the return direction
- Delta Air Lines 2769 on the same route83.8%
- Delta Air Lines 2861 on the same route74.2%
- Delta Air Lines 1628 on the same route90.6%
- Delta Air Lines 2830 on the same route83.8%
- Delta Air Lines 2914 on the same route84.0%
- Delta Air Lines 2854 on the same route74.8%
- Seattle-Tacoma International (SEA) delay statistics
- Los Angeles International (LAX) 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
- The best time of day to fly, according to 7.05 million flight records
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.