Flight number record
OO 3909
SkyWest Airlines · Detroit to Kalamazoo
- Route
- DTW → AZO
- Departs
- 22:55
- Flights
- 320
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 3909, 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 3909 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 about 2.5 hours on average. That rests on 320 flights, with a median arrival 9 minutes early.
Key figures
On time
77.2%
Arrivals under 15 minutes late, of 307 completed flights
Avg delay
148 min
Across delayed arrivals only, not all flights
Cancelled
3.75%
National rate is 1.89%
1 hour+ late
13.4%
National rate is 8.3%
These figures cover 320 flights between September 2025 and August 2026. Beyond the headline rate, 13.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When OO 3909 flies
OO 3909 flies DTW to AZO without a single fixed slot. Its most common scheduled departure was 22:55, used on 181 of 320 flights.
- Departs 22:55181 flights56.6%
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 22:55 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and OO 3909 runs 7 points better at 77.2%. 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 3909 next to DTW to AZO
Every carrier on DTW to AZO combined arrived on time 75.2% of the time across 1,058 flights, so OO 3909 is 2 points ahead of it. Across its whole network SkyWest Airlines managed 78.7%, which this flight trails by 2 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 3909thin sample | 320 | 77.2% | 148 min | 3.75% | B− |
| All SkyWest Airlines on DTW–AZO | 1,058 | 75.2% | 118 min | 2.46% | B |
| All carriers on DTW–AZO | 1,058 | 75.2% | 118 min | 2.46% | B |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 3909 quarter by quarter
OO 3909 did not run the same all year. Its best quarter was Jul–Sep 2025 at 100.0% on time and its weakest Jan–Mar 2026 at 55.4%, a swing of 45 points on roughly 64 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 flights100.0%
- Oct–Dec 202578 flights82.9%
- Jan–Mar 202659 flights55.4%
- Apr–Jun 202691 flights77.8%
- Jul–Sep 202662 flights78.2%
Scale runs 45% to 100%.
By weekday, OO 3909 did best on Saturday at 94.7% on time and worst on Wednesday at 70.0%. Each day rests on about 46 flights, so a gap of 25 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 3909 runs when it is late
OO 3909 often beats the schedule: 79 of 307 completed flights, 26%, arrived 15 minutes or more early. When OO 3909 is late it tends to be very late: 41 of its 70 late arrivals were an hour or more behind, and 23 were two hours or more.
- 15+ min early79 flights25.7%
- Within 15 min158 flights51.5%
- 15–29 min late8 flights2.6%
- 30–59 min late21 flights6.8%
- 1–2 hours late18 flights5.9%
- 2+ hours late23 flights7.5%
Scale runs 0% to 100%.
Share of 307 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 70 departures that left 15 minutes late or more, only 8 made it up before arrival. 8 flights left on time and still arrived late.
The worst days
Worst days for OO 3909
The latest arrival of the period was on 16 January 2026, 13 hours 19 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 16 January 2026 | 13 hours 19 minutes | Carrier |
| 27 May 2026 | 11 hours 10 minutes | Carrier |
| 19 May 2026 | 10 hours 40 minutes | Extreme weather |
| 21 August 2026 | 9 hours 53 minutes | Extreme weather |
| 15 February 2026 | 9 hours 29 minutes | Carrier |
Delay causes
Why OO 3909 runs late
Carrier accounts for 65% of the 10,000 delay minutes carriers reported here, and the remaining four split what is left.
- 65%Carrier
- 32%Extreme weather
- 3%National Airspace System
Extreme weather accounts for 32% 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 5.3 times the usual weather exposure. The split is drawn from 10,383 delay minutes reported on OO 3909.
Cancellations run at 3.75%, against 1.89% nationally. That is about one flight in 25 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and routes
What a delay on this flight costs
13.4% 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.
The same number turns up on one other city pair in the data, including DTW to MKE (16), but none flew often enough under OO 3909 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DTW to AZO only.
One caution: this is a thin sample. 320 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 3909
For a booking, the cancellation rate is the figure to plan around on OO 3909: 3.75% of its 320 scheduled flights did not operate. A late arrival costs about 2.5 hours, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- DTW to AZO, every carrier and departure
- AZO to DTW, the return direction
- SkyWest Airlines 3986 on the same route77.4%
- 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.