Flight number record
OO 4038
SkyWest Airlines · Billings to Salt Lake City
- Route
- BIL → SLC
- Departs
- 11:34
- Flights
- 255
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4038, 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 4038 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 17 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 255 flights, with a median arrival 13 minutes early.
Set against the rest of the country, OO 4038's record is 17 points better than the US average of 77.3%. That gap is worth roughly 168 fewer late arrivals for every thousand flights.
Key figures
On time
94.1%
Arrivals under 15 minutes late, of 253 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
0.39%
National rate is 1.89%
1 hour+ late
2.0%
National rate is 8.3%
These figures cover 255 flights between September 2025 and August 2026. The median arrival is 13 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 4038 flies
OO 4038 flies BIL to SLC without a single fixed slot. Its most common scheduled departure was 11:34, used on 67 of 255 flights, with 11:50 (63 flights) and 11:47 (28 flights) next.
- Departs 11:3467 flights26.3%
- Departs 11:5063 flights24.7%
- Departs 11:4728 flights11.0%
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 11:34 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and OO 4038 runs 16 points better at 94.1%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
OO 4038 next to BIL to SLC
Every carrier on BIL to SLC combined arrived on time 91.3% of the time across 1,074 flights, so OO 4038 is 3 points ahead of it. SkyWest flew 709 flights on the same city pair under all its flight numbers, including this one, and those ran 89.9% 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 4038thin sample | 255 | 94.1% | 70 min | 0.39% | A+ |
| All SkyWest Airlines on BIL–SLC | 709 | 89.9% | 84 min | 0.71% | A+ |
| All carriers on BIL–SLC | 1,074 | 91.3% | 88 min | 0.56% | A+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4038 quarter by quarter
Quarter by quarter OO 4038 held fairly steady: 94.4% in Jan–Mar 2026, 94.5% in Apr–Jun 2026 and 91.8% in Jul–Sep 2026. A spread of 3 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Oct–Dec 202512 flights—
- Jan–Mar 202690 flights94.4%
- Apr–Jun 202691 flights94.5%
- Jul–Sep 202662 flights91.8%
Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, OO 4038 ranged from 86.1% on Saturday to 97.3% on Monday. With about 36 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late OO 4038 runs when it is late
OO 4038 often beats the schedule: 110 of 253 completed flights, 43%, arrived 15 minutes or more early. The 15 late arrivals split 5 under half an hour, 5 between 30 and 60 minutes, and 5 an hour or more.
- 15+ min early110 flights43.5%
- Within 15 min128 flights50.6%
- 15–29 min late5 flights2.0%
- 30–59 min late5 flights2.0%
- 1–2 hours late3 flights1.2%
- 2+ hours late2 flights0.8%
Scale runs 0% to 100%.
Share of 253 completed flights by arrival against schedule.
Only 16 of 253 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 4038
The latest arrival of the period was on 29 August 2026, 5 hours 37 minutes behind schedule; most of its delay minutes were filed as extreme weather. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 29 August 2026 | 5 hours 37 minutes | Extreme weather |
| 18 February 2026 | 3 hours 40 minutes | Extreme weather |
| 25 July 2026 | 1 hour 5 minutes | Extreme weather |
| 25 August 2026 | 1 hour 5 minutes | Carrier |
| 15 May 2026 | 1 hour 3 minutes | Carrier |
Delay causes
Why OO 4038 runs late
Extreme weather accounts for 66% of the 1,046 delay minutes carriers reported here, and the remaining four split what is left.
- 66%Extreme weather
- 25%Carrier
- 9%National Airspace System
Extreme weather accounts for 66% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 11.0 times the usual weather exposure. The split is drawn from 1,046 delay minutes reported on OO 4038.
Cancellations are rare at 0.39%, 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 2.0% 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.
OO 4038 is not only a BIL to SLC flight. It also flew SLC to BIL (255 flights, 94.9% 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. 255 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 |
|---|---|---|---|---|---|
| SLC to BILthin sample | 255 | 94.9% | 55 min | 0.39% | A+ |
What to do with this
Booking OO 4038
For a booking, OO 4038 has one of the better records a US domestic flight can show: 94.1% on time and 0.39% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- BIL to SLC, every carrier and departure
- SLC to BIL, the return direction
- Delta Air Lines 1360 on the same route94.0%
- SkyWest Airlines 3828 on the same route85.1%
- 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
- 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.