Flight number record
OO 4159
SkyWest Airlines · Detroit to Appleton
- Route
- DTW → ATW
- Departs
- 21:09
- Flights
- 251
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4159, 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 4159 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.3%. The late ones land about 2.1 hours behind schedule. That rests on 251 flights, with a median arrival 11 minutes early.
The national on-time rate over the same period is 77.3%, so OO 4159 runs 6 points behind the country as a whole. Across a thousand flights that is about 61 extra late arrivals.
Key figures
On time
71.2%
Arrivals under 15 minutes late, of 243 completed flights
Avg delay
127 min
Across delayed arrivals only, not all flights
Cancelled
2.39%
National rate is 1.89%
1 hour+ late
18.5%
National rate is 8.3%
These figures cover 251 flights between September 2025 and August 2026. Beyond the headline rate, 18.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When OO 4159 flies
OO 4159 flies DTW to ATW without a single fixed slot. Its most common scheduled departure was 21:09, used on 86 of 251 flights, with 20:15 (58 flights) and 20:05 (36 flights) next.
- Departs 21:0986 flights34.3%
- Departs 20:1558 flights23.1%
- Departs 20:0536 flights14.3%
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 21:09 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and OO 4159 runs level with that at 71.2%. 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 4159 next to DTW to ATW
Every carrier on DTW to ATW combined arrived on time 75.1% of the time across 1,042 flights, so OO 4159 is 4 points behind it. SkyWest flew 974 flights on the same city pair under all its flight numbers, including this one, and those ran 74.5% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight trails by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4159thin sample | 251 | 71.2% | 127 min | 2.39% | C |
| All SkyWest Airlines on DTW–ATW | 974 | 74.5% | 98 min | 1.54% | C |
| All carriers on DTW–ATW | 1,042 | 75.1% | 96 min | 1.44% | B |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4159 quarter by quarter
OO 4159 did not run the same all year. Its best quarter was Jul–Sep 2026 at 80.3% on time and its weakest Jan–Mar 2026 at 57.5%, a swing of 23 points on roughly 84 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.
- Oct–Dec 202512 flights—
- Jan–Mar 202686 flights57.5%
- Apr–Jun 202691 flights76.7%
- Jul–Sep 202662 flights80.3%
Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, OO 4159 did best on Saturday at 85.3% on time and worst on Sunday at 63.6%. Each day rests on about 36 flights, so a gap of 22 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4159 runs when it is late
OO 4159 often beats the schedule: 101 of 243 completed flights, 42%, arrived 15 minutes or more early. When OO 4159 is late it tends to be very late: 45 of its 70 late arrivals were an hour or more behind, and 21 were two hours or more.
- 15+ min early101 flights41.6%
- Within 15 min72 flights29.6%
- 15–29 min late16 flights6.6%
- 30–59 min late9 flights3.7%
- 1–2 hours late24 flights9.9%
- 2+ hours late21 flights8.6%
Scale runs 0% to 100%.
Share of 243 completed flights by arrival against schedule.
9 of 75 late departures made up the time and arrived on time, 12% of them. Only 4 left on time and still arrived late.
The worst days
Worst days for OO 4159
The latest arrival of the period was on 11 March 2026, 13 hours 38 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 11 March 2026 | 13 hours 38 minutes | Carrier |
| 18 March 2026 | 12 hours 8 minutes | Carrier |
| 28 January 2026 | 11 hours 40 minutes | National Airspace System |
| 21 July 2026 | 9 hours 30 minutes | Carrier |
| 30 December 2025 | 5 hours 19 minutes | Carrier |
Delay causes
Why OO 4159 runs late
Carrier accounts for 75% of the 8,875 delay minutes carriers reported here, and the remaining four split what is left.
- 75%Carrier
- 14%National Airspace System
- 11%Extreme weather
Extreme weather accounts for 11% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.8 times the usual weather exposure. The split is drawn from 8,875 delay minutes reported on OO 4159.
Cancellations sit at 2.39% against a national 1.89%, which is ordinary. Diversions add another 0.80%.
Connections and routes
What a delay on this flight costs
18.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
Every one of the 251 flights under OO 4159 in the data flew DTW to ATW. 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. 251 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 4159
For a booking, OO 4159 is a flight to put a long connection behind. 18.5% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- DTW to ATW, every carrier and departure
- ATW to DTW, the return direction
- Detroit Metropolitan Wayne County (DTW) 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
- How often a connection fails at the major US hubs
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.