Flight number record
OO 4721
SkyWest Airlines · Pasco to Denver
- Route
- PSC → DEN
- Departs
- 12:45
- Flights
- 363
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4721, 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 4721 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 10 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 363 flights, with a median arrival 16 minutes early.
Set against the rest of the country, OO 4721's record is 10 points better than the US average of 77.3%. That gap is worth roughly 98 fewer late arrivals for every thousand flights.
Key figures
On time
87.1%
Arrivals under 15 minutes late, of 357 completed flights
Avg delay
81 min
Across delayed arrivals only, not all flights
Cancelled
0.28%
National rate is 1.89%
1 hour+ late
5.9%
National rate is 8.3%
These figures cover 363 flights between September 2025 and August 2026. The median arrival is 16 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 4721 flies
OO 4721 flies PSC to DEN without a single fixed slot. Its most common scheduled departure was 12:45, used on 171 of 363 flights, with 12:08 (71 flights) next.
- Departs 12:45171 flights47.1%
- Departs 12:0871 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 12:45 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and OO 4721 runs 9 points better at 87.1%. 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 4721 next to PSC to DEN
Every carrier on PSC to DEN combined arrived on time 89.1% of the time across 728 flights, so OO 4721 is 2 points behind it. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4721thin sample | 363 | 87.1% | 81 min | 0.28% | A+ |
| All SkyWest Airlines on PSC–DEN | 365 | 87.2% | 81 min | 0.27% | A+ |
| All carriers on PSC–DEN | 728 | 89.1% | 84 min | 0.55% | A+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4721 quarter by quarter
OO 4721 did not run the same all year. Its best quarter was Oct–Dec 2025 at 95.6% on time and its weakest Jan–Mar 2026 at 79.8%, a swing of 16 points on roughly 73 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 flights93.3%
- Oct–Dec 202591 flights95.6%
- Jan–Mar 202690 flights79.8%
- Apr–Jun 202691 flights85.6%
- Jul–Sep 202661 flights84.2%
Scale runs 70% to 100%.
By weekday, OO 4721 did best on Monday at 92.3% on time and worst on Thursday at 78.0%. Each day rests on about 52 flights, so a gap of 14 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4721 runs when it is late
OO 4721 often beats the schedule: 194 of 357 completed flights, 54%, arrived 15 minutes or more early. The 46 late arrivals split 12 under half an hour, 13 between 30 and 60 minutes, and 21 an hour or more.
- 15+ min early194 flights54.3%
- Within 15 min117 flights32.8%
- 15–29 min late12 flights3.4%
- 30–59 min late13 flights3.6%
- 1–2 hours late10 flights2.8%
- 2+ hours late11 flights3.1%
Scale runs 0% to 100%.
Share of 357 completed flights by arrival against schedule.
10 of 46 late departures made up the time and arrived on time, 22% of them. 10 flights left on time and still arrived late.
The worst days
Worst days for OO 4721
The latest arrival of the period was on 2 May 2026, 6 hours 4 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across May, April, February and August, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 2 May 2026 | 6 hours 4 minutes | Carrier |
| 16 April 2026 | 4 hours 35 minutes | Late-arriving aircraft |
| 26 February 2026 | 4 hours 6 minutes | Extreme weather |
| 15 August 2026 | 3 hours 11 minutes | National Airspace System |
| 12 May 2026 | 2 hours 52 minutes | Late-arriving aircraft |
Delay causes
Why OO 4721 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 3,714 reported delay minutes.
- 35%Carrier
- 33%National Airspace System
- 23%Late-arriving aircraft
- 9%Extreme weather
33% 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 1,225 minutes out of 3,714, against a national NAS share of 21%. The split is drawn from 3,714 delay minutes reported on OO 4721.
Cancellations are rare at 0.28%, 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
5.9% 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 a little over an hour, which a normal layover absorbs.
The 853 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.
Every one of the 363 flights under OO 4721 in the data flew PSC to DEN. 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. 363 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 4721
For a booking, OO 4721 has one of the better records a US domestic flight can show: 87.1% on time and 0.28% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- PSC to DEN, every carrier and departure
- DEN to PSC, the return direction
- 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.