Flight number record
OO 4738
SkyWest Airlines · Bismarck to Denver
- Route
- BIS → DEN
- Departs
- 06:00
- Flights
- 362
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4738, 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 4738 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 12 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 2.8 hours. That rests on 362 flights, with a median arrival 20 minutes early.
Set against the rest of the country, OO 4738's record is 12 points better than the US average of 77.3%. That gap is worth roughly 116 fewer late arrivals for every thousand flights.
Key figures
On time
88.9%
Arrivals under 15 minutes late, of 359 completed flights
Avg delay
168 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
1 hour+ late
5.8%
National rate is 8.3%
These figures cover 362 flights between September 2025 and August 2026. The median arrival is 20 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 4738 flies
OO 4738 flies BIS to DEN without a single fixed slot. Its most common scheduled departure was 06:00, used on 170 of 362 flights, with 05:30 (81 flights) and 05:45 (71 flights) next.
- Departs 06:00170 flights47.0%
- Departs 05:3081 flights22.4%
- Departs 05:4571 flights19.6%
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 06:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 4738 runs level with that at 88.9%. 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 4738 next to BIS to DEN
Every carrier on BIS to DEN combined arrived on time 79.9% of the time across 1,433 flights, so OO 4738 is 9 points ahead of it. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4738thin sample | 362 | 88.9% | 168 min | 0.55% | A+ |
| All SkyWest Airlines on BIS–DEN | 1,433 | 79.9% | 107 min | 0.70% | B+ |
| All carriers on BIS–DEN | 1,433 | 79.9% | 107 min | 0.70% | B+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4738 quarter by quarter
Quarter by quarter OO 4738 held fairly steady: 93.3% in Jul–Sep 2025, 85.7% in Oct–Dec 2025, 87.4% in Jan–Mar 2026, 88.9% in Apr–Jun 2026 and 93.4% 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 flights93.3%
- Oct–Dec 202591 flights85.7%
- Jan–Mar 202689 flights87.4%
- Apr–Jun 202691 flights88.9%
- Jul–Sep 202661 flights93.4%
Scale runs 75% to 100%.
By weekday, OO 4738 ranged from 84.6% on Saturday to 96.1% on Wednesday. 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.
Arrival by arrival
How late OO 4738 runs when it is late
OO 4738 often beats the schedule: 240 of 359 completed flights, 67%, arrived 15 minutes or more early. When OO 4738 is late it tends to be very late: 21 of its 40 late arrivals were an hour or more behind, and 16 were two hours or more.
- 15+ min early240 flights66.9%
- Within 15 min79 flights22.0%
- 15–29 min late11 flights3.1%
- 30–59 min late8 flights2.2%
- 1–2 hours late5 flights1.4%
- 2+ hours late16 flights4.5%
Scale runs 0% to 100%.
Share of 359 completed flights by arrival against schedule.
6 of 40 late departures made up the time and arrived on time, 15% of them. Only 6 left on time and still arrived late.
The worst days
Worst days for OO 4738
The latest arrival of the period was on 6 June 2026, 12 hours 16 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 |
|---|---|---|
| 6 June 2026 | 12 hours 16 minutes | Carrier |
| 1 December 2025 | 9 hours 11 minutes | Carrier |
| 16 October 2025 | 9 hours 4 minutes | Carrier |
| 8 June 2026 | 7 hours 27 minutes | Late-arriving aircraft |
| 28 December 2025 | 6 hours 37 minutes | Late-arriving aircraft |
Delay causes
Why OO 4738 runs late
Carrier accounts for 72% of the 6,707 delay minutes carriers reported here, and the remaining four split what is left.
- 72%Carrier
- 26%Late-arriving aircraft
- 2%National Airspace System
- 1%Extreme weather
The largest share of delay minutes, 72%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 4,810 of the 6,707 delay minutes reported here. The split is drawn from 6,707 delay minutes reported on OO 4738.
Cancellations are rare at 0.55%, 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
5.8% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 2.8 hours, which a normal layover absorbs.
The 516 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The same number turns up on three other city pairs in the data, including LIT to DEN (1), DEN to OMA (1) and IDA to DEN (1), but none flew often enough under OO 4738 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BIS to DEN only.
One caution: this is a thin sample. 362 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 4738
For a booking, OO 4738 has one of the better records a US domestic flight can show: 88.9% on time and 0.55% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- BIS to DEN, every carrier and departure
- DEN to BIS, the return direction
- SkyWest Airlines 4694 on the same route86.6%
- SkyWest Airlines 4710 on the same route78.2%
- Denver International (DEN) 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.