Flight number record

OO 4666

SkyWest Airlines · Casper to Denver

Route: CPR → DEN
Departs: 17:55
Flights: 261
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 261 flights, with a median arrival 6 minutes early.

On time

78.5%

Arrivals under 15 minutes late, of 256 completed flights

Avg delay

64 min

Across delayed arrivals only, not all flights

Cancelled

1.15%

National rate is 1.81%

1 hour+ late

7.8%

National rate is 8.1%

These figures cover 261 flights between July 2025 and June 2026. The median arrival is 6 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 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 261 flights, with 18:10 (40 flights) and 18:04 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:5549 flights18.8%
Departs 18:1040 flights15.3%
Departs 18:0437 flights14.2%

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 17:55 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and OO 4666 runs 10 points better at 78.5%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

OO 4666 next to CPR to DEN

Every carrier on CPR to DEN combined arrived on time 81.9% of the time across 2,570 flights, so OO 4666 is 3 points behind it. Across its whole network SkyWest Airlines managed 79.0%, close to this flight's figure.

OO 4666 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4666thin sample	261	78.5%	64 min	1.15%	B
All SkyWest Airlines on CPR–DEN	2,570	81.9%	88 min	0.93%	B+
All carriers on CPR–DEN	2,570	81.9%	88 min	0.93%	B+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	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 65 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 202543 flights69.8%
Oct–Dec 202561 flights83.1%
Jan–Mar 202690 flights86.4%
Apr–Jun 202667 flights69.7%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, OO 4666 did best on Tuesday at 86.5% on time and worst on Friday at 64.9%. Each day rests on about 37 flights, so a gap of 22 points is worth noticing but could still narrow in another year.

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 3,491 reported delay minutes.

National Airspace System
39%
Late-arriving aircraft
29%
Carrier
26%
Extreme weather
7%

39% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,346 minutes out of 3,491, against a national NAS share of 21%. The split is drawn from 3,491 delay minutes reported on OO 4666.

Cancellations sit at 1.15% against a national 1.81%, which is ordinary. Diversions add another 0.77%.

Connections and routes

What a delay on this flight costs

7.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says 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 four other city pairs in the data, including DEN to FCA (49), ORD to CVG (29) and DEN to PIA (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. 261 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, read OO 4666 as 78.5% on time with 1.15% cancelled over 261 flights. Those are rates from the past twelve months, not a forecast for any particular 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