Flight number record
OO 4939
SkyWest Airlines · Midland to Phoenix
- Route
- MAF → PHX
- Departs
- 09:32
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4939, 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 4939 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 about 3.3 hours. That rests on 365 flights, with a median arrival 15 minutes early.
Set against the rest of the country, OO 4939's record is 10 points better than the US average of 77.3%. That gap is worth roughly 100 fewer late arrivals for every thousand flights.
Key figures
On time
87.3%
Arrivals under 15 minutes late, of 361 completed flights
Avg delay
201 min
Across delayed arrivals only, not all flights
Cancelled
1.10%
National rate is 1.89%
1 hour+ late
8.0%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When OO 4939 flies
OO 4939 flies MAF to PHX without a single fixed slot. Its most common scheduled departure was 09:32, used on 77 of 365 flights, with 06:48 (43 flights) and 06:37 (37 flights) next.
- Departs 09:3277 flights21.1%
- Departs 06:4843 flights11.8%
- Departs 06:3737 flights10.1%
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 09:32 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and OO 4939 runs 3 points better at 87.3%. 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 4939 next to MAF to PHX
Every carrier on MAF to PHX combined arrived on time 87.3% of the time across 367 flights, so OO 4939 is about level with it. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4939 | 365 | 87.3% | 201 min | 1.10% | A |
| All SkyWest Airlines on MAF–PHX | 365 | 87.3% | 201 min | 1.10% | A |
| All carriers on MAF–PHX | 367 | 87.3% | 201 min | 1.09% | A |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4939 quarter by quarter
Quarter by quarter OO 4939 held fairly steady: 86.7% in Jul–Sep 2025, 85.9% in Oct–Dec 2025, 87.4% in Jan–Mar 2026, 87.9% in Apr–Jun 2026 and 88.5% 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.
- Jul–Sep 202530 flights86.7%
- Oct–Dec 202592 flights85.9%
- Jan–Mar 202690 flights87.4%
- Apr–Jun 202691 flights87.9%
- Jul–Sep 202662 flights88.5%
Scale runs 75% to 95%.
By weekday, OO 4939 did best on Wednesday at 98.1% on time and worst on Monday at 78.8%. Each day rests on about 52 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4939 runs when it is late
OO 4939 often beats the schedule: 183 of 361 completed flights, 51%, arrived 15 minutes or more early. When OO 4939 is late it tends to be very late: 29 of its 46 late arrivals were an hour or more behind, and 20 were two hours or more.
- 15+ min early183 flights50.7%
- Within 15 min132 flights36.6%
- 15–29 min late8 flights2.2%
- 30–59 min late9 flights2.5%
- 1–2 hours late9 flights2.5%
- 2+ hours late20 flights5.5%
Scale runs 0% to 100%.
Share of 361 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 52 departures that left 15 minutes late or more, only 6 made it up before arrival. No flight that left on time arrived late.
The worst days
Worst days for OO 4939
The latest arrival of the period was on 20 November 2025, 27 hours 11 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across November, December, March, January and April, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 20 November 2025 | 27 hours 11 minutes | Carrier |
| 14 December 2025 | 12 hours 27 minutes | Carrier |
| 10 March 2026 | 11 hours 39 minutes | Late-arriving aircraft |
| 26 January 2026 | 10 hours 7 minutes | Extreme weather |
| 20 April 2026 | 9 hours 13 minutes | Late-arriving aircraft |
Delay causes
Why OO 4939 runs late
Carrier accounts for 56% of the 9,227 delay minutes carriers reported here, and the remaining four split what is left.
- 56%Carrier
- 32%Late-arriving aircraft
- 10%Extreme weather
- 2%National Airspace System
The largest share of delay minutes, 56%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 5,176 of the 9,227 delay minutes reported here. The split is drawn from 9,227 delay minutes reported on OO 4939.
Cancellations sit at 1.10% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
8.0% 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 3.3 hours, which a normal layover absorbs.
The 581 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 365 flights under OO 4939 in the data flew MAF to PHX. 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. 365 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 4939
For a booking, OO 4939 has one of the better records a US domestic flight can show: 87.3% on time and 1.10% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- Phoenix Sky Harbor International (PHX) 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
- Connecting flights: how much buffer the data says you need
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.