Flight number record
OO 3977
SkyWest Airlines · Lexington to Detroit
- Route
- LEX → DTW
- Departs
- 07:45
- Flights
- 329
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 3977, 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 3977 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 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs close to two hours. That rests on 329 flights, with a median arrival 13 minutes early.
Set against the rest of the country, OO 3977's record is 11 points better than the US average of 77.3%. That gap is worth roughly 110 fewer late arrivals for every thousand flights.
Key figures
On time
88.3%
Arrivals under 15 minutes late, of 325 completed flights
Avg delay
124 min
Across delayed arrivals only, not all flights
Cancelled
1.22%
National rate is 1.89%
1 hour+ late
6.5%
National rate is 8.3%
These figures cover 329 flights between September 2025 and August 2026. The median arrival is 13 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 3977 flies
OO 3977 flies LEX to DTW without a single fixed slot. Its most common scheduled departure was 07:45, used on 113 of 329 flights, with 07:35 (78 flights) and 07:26 (55 flights) next.
- Departs 07:45113 flights34.3%
- Departs 07:3578 flights23.7%
- Departs 07:2655 flights16.7%
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 07:45 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 3977 runs level with that at 88.3%. 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 3977 next to LEX to DTW
Every carrier on LEX to DTW combined arrived on time 84.2% of the time across 788 flights, so OO 3977 is 4 points ahead of it. SkyWest flew 571 flights on the same city pair under all its flight numbers, including this one, and those ran 84.9% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 3977thin sample | 329 | 88.3% | 124 min | 1.22% | A |
| All SkyWest Airlines on LEX–DTW | 571 | 84.9% | 137 min | 1.23% | B |
| All carriers on LEX–DTW | 788 | 84.2% | 121 min | 1.14% | B |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 3977 quarter by quarter
OO 3977 did not run the same all year. Its best quarter was Apr–Jun 2026 at 93.2% on time and its weakest Jan–Mar 2026 at 77.5%, a swing of 16 points on roughly 82 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 202524 flights—
- Oct–Dec 202578 flights88.2%
- Jan–Mar 202682 flights77.5%
- Apr–Jun 202688 flights93.2%
- Jul–Sep 202657 flights91.2%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, OO 3977 did best on Thursday at 95.9% on time and worst on Monday at 81.2%. Each day rests on about 47 flights, so a gap of 15 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 3977 runs when it is late
OO 3977 often beats the schedule: 143 of 325 completed flights, 44%, arrived 15 minutes or more early. When OO 3977 is late it tends to be very late: 21 of its 38 late arrivals were an hour or more behind, and 16 were two hours or more.
- 15+ min early143 flights44.0%
- Within 15 min144 flights44.3%
- 15–29 min late8 flights2.5%
- 30–59 min late9 flights2.8%
- 1–2 hours late5 flights1.5%
- 2+ hours late16 flights4.9%
Scale runs 0% to 100%.
Share of 325 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 35 departures that left 15 minutes late or more, only 4 made it up before arrival. 7 flights left on time and still arrived late.
The worst days
Worst days for OO 3977
The latest arrival of the period was on 18 March 2026, 9 hours 41 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 |
|---|---|---|
| 18 March 2026 | 9 hours 41 minutes | Carrier |
| 17 August 2026 | 7 hours 48 minutes | Extreme weather |
| 5 December 2025 | 4 hours 51 minutes | Carrier |
| 5 July 2026 | 3 hours 42 minutes | Carrier |
| 8 June 2026 | 3 hours 36 minutes | Carrier |
Delay causes
Why OO 3977 runs late
Carrier accounts for 63% of the 4,726 delay minutes carriers reported here, and the remaining four split what is left.
- 63%Carrier
- 33%Extreme weather
- 4%National Airspace System
Extreme weather accounts for 33% 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 5.4 times the usual weather exposure. The split is drawn from 4,726 delay minutes reported on OO 3977.
Cancellations sit at 1.22% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
6.5% 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 close to two hours, which a normal layover absorbs.
The same number turns up on three other city pairs in the data, including ELM to DTW (16), DTW to HSV (1) and HSV to DTW (1), but none flew often enough under OO 3977 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to LEX to DTW only.
One caution: this is a thin sample. 329 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 3977
For a booking, OO 3977 has one of the better records a US domestic flight can show: 88.3% on time and 1.22% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- LEX to DTW, every carrier and departure
- DTW to LEX, 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
- The best time of day to fly, according to 7.05 million flight records
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.