Flight number record
AS 508
Alaska Airlines · Seattle to Cincinnati
- Route
- SEA → CVG
- Departs
- 08:39
- Flights
- 348
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 508, check with Alaska Airlines.
AS 508 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 roughly 40 minutes on average. That rests on 348 flights, with a median arrival 10 minutes early.
Set against the rest of the country, AS 508's record is 6 points better than the US average of 77.3%. That gap is worth roughly 63 fewer late arrivals for every thousand flights.
Key figures
On time
83.6%
Arrivals under 15 minutes late, of 341 completed flights
Avg delay
41 min
Across delayed arrivals only, not all flights
Cancelled
1.44%
National rate is 1.89%
1 hour+ late
2.9%
National rate is 8.3%
These figures cover 348 flights between September 2025 and August 2026. The median arrival is 10 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 508 flies
AS 508 flies SEA to CVG without a single fixed slot. Its most common scheduled departure was 08:39, used on 70 of 348 flights, with 10:14 (41 flights) and 12:21 (36 flights) next.
- Departs 08:3970 flights20.1%
- Departs 10:1441 flights11.8%
- Departs 12:2136 flights10.3%
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 08:39 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and AS 508 runs level with that at 83.6%. 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 508 next to SEA to CVG
Every carrier on SEA to CVG combined arrived on time 86.2% of the time across 793 flights, so AS 508 is 3 points behind it. Across its whole network Alaska Airlines managed 79.7%, which this flight beats by 4 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 508thin sample | 348 | 83.6% | 41 min | 1.44% | B |
| All Alaska Airlines on SEA–CVG | 431 | 83.2% | 40 min | 1.16% | B |
| All carriers on SEA–CVG | 793 | 86.2% | 46 min | 1.13% | A |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 508 quarter by quarter
AS 508 did not run the same all year. Its best quarter was Jul–Sep 2026 at 93.5% on time and its weakest Oct–Dec 2025 at 79.5%, a swing of 14 points on roughly 70 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 flights86.7%
- Oct–Dec 202589 flights79.5%
- Jan–Mar 202689 flights82.6%
- Apr–Jun 202691 flights82.4%
- Jul–Sep 202649 flights93.5%
Scale runs 70% to 100%.
By weekday, AS 508 did best on Tuesday at 89.8% on time and worst on Sunday at 70.8%. Each day rests on about 50 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 508 runs when it is late
AS 508 often beats the schedule: 136 of 341 completed flights, 40%, arrived 15 minutes or more early. The 56 late arrivals split 27 under half an hour, 19 between 30 and 60 minutes, and 10 an hour or more.
- 15+ min early136 flights39.9%
- Within 15 min149 flights43.7%
- 15–29 min late27 flights7.9%
- 30–59 min late19 flights5.6%
- 1–2 hours late7 flights2.1%
- 2+ hours late3 flights0.9%
Scale runs 0% to 100%.
Share of 341 completed flights by arrival against schedule.
A late pushback is often recovered here: of 69 departures that left 15 minutes late or more, 26 still arrived on time. 13 flights left on time and still arrived late.
The worst days
Worst days for AS 508
The latest arrival of the period was on 25 December 2025, 2 hours 26 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 |
|---|---|---|
| 25 December 2025 | 2 hours 26 minutes | Carrier |
| 7 April 2026 | 2 hours 14 minutes | National Airspace System |
| 22 March 2026 | 2 hours 8 minutes | Carrier |
| 11 March 2026 | 1 hour 40 minutes | Carrier |
| 2 January 2026 | 1 hour 30 minutes | Late-arriving aircraft |
Delay causes
Why AS 508 runs late
Carrier accounts for 48% of the 2,300 delay minutes carriers reported here, and the remaining four split what is left.
- 48%Carrier
- 27%Late-arriving aircraft
- 26%National Airspace System
The largest share of delay minutes, 48%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,100 of the 2,300 delay minutes reported here. The split is drawn from 2,300 delay minutes reported on AS 508.
Cancellations sit at 1.44% against a national 1.89%, which is ordinary. Diversions add another 0.57%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 2.9% 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.
At 1,965 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.
AS 508 is not only a SEA to CVG flight. It also flew CVG to SEA (278 flights, 71.3% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 348 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| CVG to SEAthin sample | 278 | 71.3% | 54 min | 1.08% | C |
What to do with this
Booking AS 508
For a booking, read AS 508 as 83.6% on time with 1.44% cancelled over 348 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SEA to CVG, every carrier and departure
- CVG to SEA, the return direction
- Delta Air Lines 558 on the same route89.5%
- Seattle-Tacoma International (SEA) delay statistics
- Cincinnati/Northern Kentucky International (CVG) 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
- Worst months to fly in the US, ranked by the data
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.