Flight number record
OO 4666
SkyWest Airlines · Casper to Denver
- Route
- CPR → DEN
- Departs
- 17:55
- Flights
- 269
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4666, 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 4666 lands a B, level with the national rate of 77.3%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 269 flights, with a median arrival 5 minutes early.
Key figures
On time
77.1%
Arrivals under 15 minutes late, of 262 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
1.86%
National rate is 1.89%
1 hour+ late
7.6%
National rate is 8.3%
These figures cover 269 flights between September 2025 and August 2026. The median arrival is 5 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 4666 flies
OO 4666 flies CPR to DEN without a single fixed slot. Its most common scheduled departure was 17:55, used on 49 of 269 flights, with 18:10 (40 flights) and 18:04 (37 flights) next.
- Departs 17:5549 flights18.2%
- Departs 18:1040 flights14.9%
- Departs 18:0437 flights13.8%
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 17:55 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and OO 4666 runs 9 points better at 77.1%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
OO 4666 next to CPR to DEN
Every carrier on CPR to DEN combined arrived on time 83.1% of the time across 2,629 flights, so OO 4666 is 6 points behind it. Across its whole network SkyWest Airlines managed 78.7%, which this flight trails by 2 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4666thin sample | 269 | 77.1% | 64 min | 1.86% | B |
| All SkyWest Airlines on CPR–DEN | 2,629 | 83.1% | 91 min | 0.95% | B+ |
| All carriers on CPR–DEN | 2,629 | 83.1% | 91 min | 0.95% | B+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4666 quarter by quarter
OO 4666 did not run the same all year. Its best quarter was Jan–Mar 2026 at 86.4% on time and its weakest Apr–Jun 2026 at 69.7%, a swing of 17 points on roughly 67 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 flights76.7%
- Oct–Dec 202561 flights83.1%
- Jan–Mar 202690 flights86.4%
- Apr–Jun 202667 flights69.7%
- Jul–Sep 202621 flights—
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, OO 4666 did best on Tuesday at 89.5% on time and worst on Friday at 64.9%. Each day rests on about 38 flights, so a gap of 25 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4666 runs when it is late
OO 4666 often beats the schedule: 87 of 262 completed flights, 33%, arrived 15 minutes or more early. The 60 late arrivals split 18 under half an hour, 22 between 30 and 60 minutes, and 20 an hour or more.
- 15+ min early87 flights33.2%
- Within 15 min115 flights43.9%
- 15–29 min late18 flights6.9%
- 30–59 min late22 flights8.4%
- 1–2 hours late11 flights4.2%
- 2+ hours late9 flights3.4%
Scale runs 0% to 100%.
Share of 262 completed flights by arrival against schedule.
9 of 51 late departures made up the time and arrived on time, 18% of them. In the other direction, 18 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DEN.
The worst days
Worst days for OO 4666
The latest arrival of the period was on 13 August 2026, 4 hours 42 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The five worst days are spread across August, September, April, December and October, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 August 2026 | 4 hours 42 minutes | National Airspace System |
| 16 September 2025 | 4 hours 14 minutes | Carrier |
| 1 April 2026 | 3 hours 20 minutes | Late-arriving aircraft |
| 19 December 2025 | 3 hours 15 minutes | Extreme weather |
| 27 October 2025 | 2 hours 47 minutes | National Airspace System |
Delay causes
Why OO 4666 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 3,817 reported delay minutes.
- 36%Late-arriving aircraft
- 34%National Airspace System
- 23%Carrier
- 7%Extreme weather
36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 3,817 reported delay minutes here, that single category outweighs weather by 5 to one. The split is drawn from 3,817 delay minutes reported on OO 4666.
Cancellations sit at 1.86% against a national 1.89%, which is ordinary. Diversions add another 0.74%.
Connections and routes
What a delay on this flight costs
7.6% 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 an hour, which a normal layover absorbs.
The same number turns up on five other city pairs in the data, including ORD to CVG (29), SFO to PHX (1) and ORD to TUS (1), but none flew often enough under OO 4666 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to CPR to DEN only.
One caution: this is a thin sample. 269 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 4666
For a booking, OO 4666 is one of the weaker ways to fly CPR to DEN: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.
Related
Where to go next
- CPR to DEN, every carrier and departure
- DEN to CPR, the return direction
- SkyWest Airlines 5245 on the same route84.0%
- SkyWest Airlines 5818 on the same route88.1%
- SkyWest Airlines 4658 on the same route88.5%
- SkyWest Airlines 5513 on the same route91.6%
- SkyWest Airlines 4631 on the same route83.8%
- SkyWest Airlines 5809 on the same route77.1%
- 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
- Why the first flight of the morning is statistically safest
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.