Flight number record
OO 4128
SkyWest Airlines · Eugene to Seattle
- Route
- EUG → SEA
- Departs
- 07:00
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4128, check with SkyWest Airlines. SkyWest Airlines flies under contract for larger airlines, so a ticket for this flight may show a different airline code and number.
OO 4128 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 16 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 365 flights, with a median arrival 15 minutes early.
Set against the rest of the country, OO 4128's record is 16 points better than the US average of 77.3%. That gap is worth roughly 164 fewer late arrivals for every thousand flights.
Key figures
On time
93.7%
Arrivals under 15 minutes late, of 363 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
0.27%
National rate is 1.89%
1 hour+ late
2.8%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 15 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 OO 4128 flies
OO 4128 flies EUG to SEA without a single fixed slot. Its most common scheduled departure was 07:00, used on 75 of 365 flights, with 06:15 (61 flights) and 06:10 (60 flights) next.
- Departs 07:0075 flights20.5%
- Departs 06:1561 flights16.7%
- Departs 06:1060 flights16.4%
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 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 4128 runs 4 points better at 93.7%. 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
OO 4128 next to EUG to SEA
Every carrier on EUG to SEA combined arrived on time 87.5% of the time across 1,897 flights, so OO 4128 is 6 points ahead of it. SkyWest flew 1,632 flights on the same city pair under all its flight numbers, including this one, and those ran 86.9% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 15 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4128 | 365 | 93.7% | 75 min | 0.27% | A+ |
| All SkyWest Airlines on EUG–SEA | 1,632 | 86.9% | 68 min | 1.41% | A |
| All carriers on EUG–SEA | 1,897 | 87.5% | 66 min | 1.37% | A |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4128 quarter by quarter
OO 4128 did not run the same all year. Its best quarter was Jul–Sep 2025 at 100.0% on time and its weakest Jan–Mar 2026 at 88.8%, a swing of 11 points on roughly 73 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 flights100.0%
- Oct–Dec 202592 flights91.3%
- Jan–Mar 202690 flights88.8%
- Apr–Jun 202691 flights97.8%
- Jul–Sep 202662 flights95.1%
Scale runs 80% to 100%.
By weekday, OO 4128 ranged from 90.4% on Sunday to 96.2% on Monday. With about 52 flights behind each day, a spread of 6 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late OO 4128 runs when it is late
OO 4128 often beats the schedule: 186 of 363 completed flights, 51%, arrived 15 minutes or more early. The 23 late arrivals split 8 under half an hour, 5 between 30 and 60 minutes, and 10 an hour or more.
- 15+ min early186 flights51.2%
- Within 15 min154 flights42.4%
- 15–29 min late8 flights2.2%
- 30–59 min late5 flights1.4%
- 1–2 hours late5 flights1.4%
- 2+ hours late5 flights1.4%
Scale runs 0% to 100%.
Share of 363 completed flights by arrival against schedule.
Only 17 of 363 completed flights left 15 minutes late or more, too few to say how often the time is made up.
The worst days
Worst days for OO 4128
The latest arrival of the period was on 22 February 2026, 6 hours 17 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 22 February 2026 | 6 hours 17 minutes | Carrier |
| 7 March 2026 | 2 hours 22 minutes | Carrier |
| 3 August 2026 | 2 hours 17 minutes | Carrier |
| 2 October 2025 | 2 hours 12 minutes | Carrier |
| 29 March 2026 | 2 hours 9 minutes | Carrier |
Delay causes
Why OO 4128 runs late
Carrier accounts for 96% of the 1,725 delay minutes carriers reported here, and the remaining four split what is left.
- 96%Carrier
- 3%National Airspace System
- 1%Extreme weather
The largest share of delay minutes, 96%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,658 of the 1,725 delay minutes reported here. The split is drawn from 1,725 delay minutes reported on OO 4128.
Cancellations are rare at 0.27%, 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 2.8% 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.
Every one of the 365 flights under OO 4128 in the data flew EUG 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. 365 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 OO 4128
For a booking, OO 4128 has one of the better records a US domestic flight can show: 93.7% on time and 0.27% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- EUG to SEA, every carrier and departure
- SEA to EUG, the return direction
- SkyWest Airlines 4124 on the same route90.7%
- Seattle-Tacoma International (SEA) delay statistics
- SkyWest Airlines on-time record
- Every SkyWest 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 SkyWest 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.