Flight number record
AS 587
Alaska Airlines · Chicago to Seattle
- Route
- ORD → SEA
- Departs
- 08:00
- Flights
- 267
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 587, check with Alaska Airlines.
AS 587 draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 267 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.3%, so AS 587 runs 11 points behind the country as a whole. Across a thousand flights that is about 114 extra late arrivals.
Key figures
On time
65.9%
Arrivals under 15 minutes late, of 264 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
0.75%
National rate is 1.89%
1 hour+ late
11.4%
National rate is 8.3%
These figures cover 267 flights between September 2025 and August 2026. Beyond the headline rate, 11.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When AS 587 flies
AS 587 flies ORD to SEA without a single fixed slot. Its most common scheduled departure was 08:00, used on 150 of 267 flights, with 08:02 (70 flights) and 07:00 (34 flights) next.
- Departs 08:00150 flights56.2%
- Departs 08:0270 flights26.2%
- Departs 07:0034 flights12.7%
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 08:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and AS 587 runs 18 points worse at 65.9%. 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 587 next to ORD to SEA
Every carrier on ORD to SEA combined arrived on time 67.5% of the time across 5,542 flights, so AS 587 is 2 points behind it. Alaska flew 1,778 flights on the same city pair under all its flight numbers, including this one, and those ran 65.4% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight trails by 14 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 587thin sample | 267 | 65.9% | 73 min | 0.75% | C+ |
| All Alaska Airlines on ORD–SEA | 1,778 | 65.4% | 68 min | 1.80% | C |
| All carriers on ORD–SEA | 5,542 | 67.5% | 66 min | 1.37% | C |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 587 quarter by quarter
AS 587 did not run the same all year. Its best quarter was Apr–Jun 2026 at 73.8% on time and its weakest Oct–Dec 2025 at 55.8%, a swing of 18 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.
- Oct–Dec 202588 flights55.8%
- Jan–Mar 202675 flights70.7%
- Apr–Jun 202642 flights73.8%
- Jul–Sep 202662 flights68.9%
Scale runs 45% to 80%.
By weekday, AS 587 ranged from 60.5% on Sunday to 70.3% on Wednesday. With about 38 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late AS 587 runs when it is late
The 90 late arrivals split 38 under half an hour, 22 between 30 and 60 minutes, and 30 an hour or more.
- 15+ min early49 flights18.6%
- Within 15 min125 flights47.3%
- 15–29 min late38 flights14.4%
- 30–59 min late22 flights8.3%
- 1–2 hours late20 flights7.6%
- 2+ hours late10 flights3.8%
Scale runs 0% to 100%.
Share of 264 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 45 departures that left 15 minutes late or more, only 4 made it up before arrival. In the other direction, 49 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 587
The latest arrival of the period was on 30 November 2025, 12 hours 20 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 November 2025 | 12 hours 20 minutes | Carrier |
| 11 March 2026 | 11 hours 8 minutes | Late-arriving aircraft |
| 8 July 2026 | 10 hours 58 minutes | Carrier |
| 11 December 2025 | 3 hours 53 minutes | Carrier |
| 13 March 2026 | 3 hours 18 minutes | National Airspace System |
Delay causes
Why AS 587 runs late
Carrier accounts for 48% of the 6,566 delay minutes carriers reported here, and the remaining four split what is left.
- 48%Carrier
- 36%National Airspace System
- 15%Late-arriving aircraft
- 1%Extreme weather
- 0%Security
The largest share of delay minutes, 48%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,133 of the 6,566 delay minutes reported here. The split is drawn from 6,566 delay minutes reported on AS 587.
Cancellations are rare at 0.75%, 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
11.4% 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 1,721 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.
Every one of the 267 flights under AS 587 in the data flew ORD to SEA. 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. 267 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 587
For a booking, read AS 587 as 65.9% on time with 0.75% cancelled over 267 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- ORD to SEA, every carrier and departure
- SEA to ORD, the return direction
- Delta Air Lines 2041 on the same route72.8%
- Alaska Airlines 407 on the same route63.4%
- Alaska Airlines 329 on the same route62.5%
- United Airlines 2211 on the same route57.6%
- Chicago O'Hare International (ORD) 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.