Flight number record

AS 278

Alaska Airlines · Portland to Los Angeles

Route: PDX → LAX
Departs: 17:40
Flights: 344
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 278, check with Alaska Airlines.

AS 278 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 344 flights, with a median arrival 8 minutes early.

Set against the rest of the country, AS 278's record is 12 points better than the US average of 77.6%. That gap is worth roughly 116 fewer late arrivals for every thousand flights.

On time

89.2%

Arrivals under 15 minutes late, of 344 completed flights

Avg delay

70 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

1 hour+ late

3.8%

National rate is 8.1%

These figures cover 344 flights between July 2025 and June 2026. The median arrival is 8 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.

Schedule

When AS 278 flies

AS 278 flies PDX to LAX without a single fixed slot. Its most common scheduled departure was 17:40, used on 66 of 344 flights, with 17:49 (47 flights) and 17:35 (45 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:4066 flights19.2%
Departs 17:4947 flights13.7%
Departs 17:3545 flights13.1%

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 17:40 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and AS 278 runs 21 points better at 89.2%. 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 278 next to PDX to LAX

Every carrier on PDX to LAX combined arrived on time 87.4% of the time across 4,403 flights, so AS 278 is 2 points ahead of it. Alaska flew 1,897 flights on the same city pair under all its flight numbers, including this one, and those ran 86.5% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight beats by 10 points.

AS 278 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 278thin sample	344	89.2%	70 min	0.00%	A+
All Alaska Airlines on PDX–LAX	1,897	86.5%	49 min	0.84%	A+
All carriers on PDX–LAX	4,403	87.4%	79 min	0.89%	A+
Alaska Airlines, whole network	293,372	79.1%	52 min	1.28%	B

Across the year

AS 278 quarter by quarter

Quarter by quarter AS 278 held fairly steady: 91.8% in Jul–Sep 2025, 86.5% in Oct–Dec 2025, 89.4% in Jan–Mar 2026 and 89.4% in Apr–Jun 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202585 flights91.8%
Oct–Dec 202589 flights86.5%
Jan–Mar 202685 flights89.4%
Apr–Jun 202685 flights89.4%

Scale runs 80% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, AS 278 did best on Tuesday at 98.1% on time and worst on Friday at 80.0%. Each day rests on about 49 flights, so a gap of 18 points is worth noticing but could still narrow in another year.

Delay causes

Why AS 278 runs late

One category carries most of the weight here. Carrier accounts for 53% of the 2,603 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.

Carrier
53%
Late-arriving aircraft
39%
National Airspace System
8%
Extreme weather
0%

39% 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 2,603 reported delay minutes here, that single category outweighs weather by 39 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 2,603 delay minutes reported on AS 278.

Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are 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 3.8% land an hour or more behind schedule, against 8.1% 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 833 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

Every one of the 344 flights under AS 278 in the data flew PDX 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. 344 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 278

For a booking, AS 278 has one of the better records a US domestic flight can show: 89.2% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.

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