Flight number record

OO 4128

SkyWest Airlines · Eugene to Seattle

Route: EUG → SEA
Departs: 06:30
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 365 flights, with a median arrival 16 minutes early.

Set against the rest of the country, OO 4128's record is 16 points better than the US average of 77.6%. That gap is worth roughly 161 fewer late arrivals for every thousand flights.

On time

93.7%

Arrivals under 15 minutes late, of 364 completed flights

Avg delay

78 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

1 hour+ late

2.7%

National rate is 8.1%

These figures cover 365 flights between July 2025 and June 2026. The median arrival is 16 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 OO 4128 flies

OO 4128 flies EUG to SEA without a single fixed slot. Its most common scheduled departure was 06:30, used on 111 of 365 flights, with 07:00 (75 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 06:30111 flights30.4%
Departs 07:0075 flights20.5%

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 06:30 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.

Against the route

OO 4128 next to EUG to SEA

Every carrier on EUG to SEA combined arrived on time 87.8% of the time across 1,954 flights, so OO 4128 is 6 points ahead of it. SkyWest flew 1,565 flights on the same city pair under all its flight numbers, including this one, and those ran 88.3% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 15 points.

OO 4128 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4128	365	93.7%	78 min	0.00%	A+
All SkyWest Airlines on EUG–SEA	1,565	88.3%	65 min	1.41%	A
All carriers on EUG–SEA	1,954	87.8%	62 min	1.38%	A
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 4128 quarter by quarter

Quarter by quarter OO 4128 held fairly steady: 96.7% in Jul–Sep 2025, 91.3% in Oct–Dec 2025, 88.8% in Jan–Mar 2026 and 97.8% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights96.7%
Oct–Dec 202592 flights91.3%
Jan–Mar 202690 flights88.8%
Apr–Jun 202691 flights97.8%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, OO 4128 ranged from 88.5% on Saturday to 100.0% on Monday. With about 52 flights behind each day, a spread of 12 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why OO 4128 runs late

One category carries most of the weight here. Carrier accounts for 95% of the 1,782 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
95%
National Airspace System
4%
Extreme weather
1%

The largest share of delay minutes, 95%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,696 of the 1,782 delay minutes reported here. The split is drawn from 1,782 delay minutes reported on OO 4128.

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 2.7% 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.

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 0.00% cancelled. That is a base rate, not a promise about any single day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures