Flight number record
OO 4311
SkyWest Airlines · Elko to Salt Lake City
- Route
- EKO → SLC
- Departs
- 06:30
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4311, 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 4311 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 19 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 3.2 hours. That rests on 365 flights, with a median arrival 23 minutes early.
Set against the rest of the country, OO 4311's record is 19 points better than the US average of 77.3%. That gap is worth roughly 191 fewer late arrivals for every thousand flights.
Key figures
On time
96.4%
Arrivals under 15 minutes late, of 362 completed flights
Avg delay
191 min
Across delayed arrivals only, not all flights
Cancelled
0.82%
National rate is 1.89%
1 hour+ late
2.2%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 23 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 4311 flies
OO 4311 is scheduled to leave Elko (EKO) at 06:30 local time and reach Salt Lake City (SLC) at 08:34. That slot held for 364 of the 365 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.
- Departs 06:30364 flights99.7%
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 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 4311 runs 7 points better at 96.4%. 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 4311 next to EKO to SLC
Every carrier on EKO to SLC combined arrived on time 95.5% of the time across 579 flights, so OO 4311 is about level with it. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 18 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4311 | 365 | 96.4% | 191 min | 0.82% | A+ |
| All SkyWest Airlines on EKO–SLC | 579 | 95.5% | 140 min | 0.69% | A+ |
| All carriers on EKO–SLC | 579 | 95.5% | 140 min | 0.69% | A+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4311 quarter by quarter
Quarter by quarter OO 4311 held fairly steady: 100.0% in Jul–Sep 2025, 98.9% in Oct–Dec 2025, 96.6% in Jan–Mar 2026, 92.2% in Apr–Jun 2026 and 96.8% in Jul–Sep 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights100.0%
- Oct–Dec 202592 flights98.9%
- Jan–Mar 202690 flights96.6%
- Apr–Jun 202691 flights92.2%
- Jul–Sep 202662 flights96.8%
Scale runs 85% to 100%.
By weekday, OO 4311 ranged from 90.4% on Saturday to 100.0% on Monday. With about 52 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 OO 4311 runs when it is late
OO 4311 often beats the schedule: 287 of 362 completed flights, 79%, arrived 15 minutes or more early. When OO 4311 is late it tends to be very late: 8 of its 13 late arrivals were an hour or more behind, and 5 were two hours or more.
- 15+ min early287 flights79.3%
- Within 15 min62 flights17.1%
- 15–29 min late1 flights0.3%
- 30–59 min late4 flights1.1%
- 1–2 hours late3 flights0.8%
- 2+ hours late5 flights1.4%
Scale runs 0% to 100%.
Share of 362 completed flights by arrival against schedule.
Only 13 of 362 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 4311
The latest arrival of the period was on 4 August 2026, 11 hours 23 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 4 August 2026 | 11 hours 23 minutes | Carrier |
| 7 April 2026 | 7 hours 56 minutes | Carrier |
| 13 June 2026 | 6 hours 48 minutes | Carrier |
| 25 February 2026 | 4 hours 32 minutes | Extreme weather |
| 21 June 2026 | 2 hours 51 minutes | Carrier |
Delay causes
Why OO 4311 runs late
Carrier accounts for 88% of the 2,476 delay minutes carriers reported here, and the remaining four split what is left.
- 88%Carrier
- 11%Extreme weather
- 1%National Airspace System
The largest share of delay minutes, 88%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,186 of the 2,476 delay minutes reported here. The split is drawn from 2,476 delay minutes reported on OO 4311.
Cancellations are rare at 0.82%, 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 2.2% 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 4311 in the data flew EKO to SLC. 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 4311
For a booking, OO 4311 has one of the better records a US domestic flight can show: 96.4% on time and 0.82% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- Salt Lake City International (SLC) 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
- The best day of the week to fly, and why it is the second lever
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.