Flight number record
OO 4129
SkyWest Airlines · Minneapolis to Washington
- Route
- MSP → IAD
- Departs
- 19:50
- Flights
- 253
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4129, 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 4129 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 an hour and a half on average. That rests on 253 flights, with a median arrival 10 minutes early.
Key figures
On time
77.4%
Arrivals under 15 minutes late, of 248 completed flights
Avg delay
84 min
Across delayed arrivals only, not all flights
Cancelled
1.98%
National rate is 1.89%
1 hour+ late
7.3%
National rate is 8.3%
These figures cover 253 flights between September 2025 and August 2026. The median arrival is 10 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 4129 flies
OO 4129 flies MSP to IAD without a single fixed slot. Its most common scheduled departure was 19:50, used on 55 of 253 flights, with 20:19 (49 flights) and 20:08 (31 flights) next.
- Departs 19:5055 flights21.7%
- Departs 20:1949 flights19.4%
- Departs 20:0831 flights12.3%
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 19:50 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and OO 4129 runs 9 points better at 77.4%. 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 4129 next to MSP to IAD
Every carrier on MSP to IAD combined arrived on time 82.2% of the time across 1,024 flights, so OO 4129 is 5 points behind it. SkyWest flew 849 flights on the same city pair under all its flight numbers, including this one, and those ran 80.3% on time. Across its whole network SkyWest Airlines managed 78.7%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4129thin sample | 253 | 77.4% | 84 min | 1.98% | B |
| All SkyWest Airlines on MSP–IAD | 849 | 80.3% | 68 min | 1.06% | B |
| All carriers on MSP–IAD | 1,024 | 82.2% | 74 min | 1.56% | B |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4129 quarter by quarter
Quarter by quarter OO 4129 held fairly steady: 80.0% in Jan–Mar 2026, 76.7% in Apr–Jun 2026 and 75.4% in Jul–Sep 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Oct–Dec 202512 flights—
- Jan–Mar 202690 flights80.0%
- Apr–Jun 202690 flights76.7%
- Jul–Sep 202661 flights75.4%
Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, OO 4129 did best on Saturday at 86.1% on time and worst on Tuesday at 69.4%. Each day rests on about 36 flights, so a gap of 17 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4129 runs when it is late
OO 4129 often beats the schedule: 99 of 248 completed flights, 40%, arrived 15 minutes or more early. The 56 late arrivals split 22 under half an hour, 16 between 30 and 60 minutes, and 18 an hour or more.
- 15+ min early99 flights39.9%
- Within 15 min93 flights37.5%
- 15–29 min late22 flights8.9%
- 30–59 min late16 flights6.5%
- 1–2 hours late12 flights4.8%
- 2+ hours late6 flights2.4%
Scale runs 0% to 100%.
Share of 248 completed flights by arrival against schedule.
9 of 46 late departures made up the time and arrived on time, 20% of them. In the other direction, 19 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 IAD.
The worst days
Worst days for OO 4129
The latest arrival of the period was on 22 January 2026, 15 hours 13 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 22 January 2026 | 15 hours 13 minutes | Carrier |
| 19 May 2026 | 11 hours 4 minutes | Carrier |
| 9 April 2026 | 10 hours 56 minutes | Carrier |
| 17 March 2026 | 2 hours 36 minutes | Carrier |
| 23 January 2026 | 2 hours 28 minutes | Carrier |
Delay causes
Why OO 4129 runs late
Carrier accounts for 80% of the 4,695 delay minutes carriers reported here, and the remaining four split what is left.
- 80%Carrier
- 10%Extreme weather
- 9%National Airspace System
- 1%Security
The largest share of delay minutes, 80%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,750 of the 4,695 delay minutes reported here. The split is drawn from 4,695 delay minutes reported on OO 4129.
Cancellations sit at 1.98% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
7.3% 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 an hour and a half, which a normal layover absorbs.
The 907 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 two other city pairs in the data, including MSP to RAP (22) and RAP to MSP (22), but none flew often enough under OO 4129 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to MSP to IAD only.
One caution: this is a thin sample. 253 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 4129
For a booking, read OO 4129 as 77.4% on time with 1.98% cancelled over 253 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- MSP to IAD, every carrier and departure
- IAD to MSP, the return direction
- SkyWest Airlines 3783 on the same route78.5%
- Minneapolis-St Paul International (MSP) delay statistics
- Washington Dulles International (IAD) 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.