Flight number record

OO 3977

SkyWest Airlines · Lexington to Detroit

Route: LEX → DTW
Departs: 07:45
Flights: 333
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 333 flights, with a median arrival 11 minutes early.

Set against the rest of the country, OO 3977's record is 8 points better than the US average of 77.6%. That gap is worth roughly 75 fewer late arrivals for every thousand flights.

On time

85.1%

Arrivals under 15 minutes late, of 329 completed flights

Avg delay

95 min

Across delayed arrivals only, not all flights

Cancelled

1.20%

National rate is 1.81%

1 hour+ late

7.3%

National rate is 8.1%

These figures cover 333 flights between July 2025 and June 2026. The median arrival is 11 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.

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 134 of 333 flights, with 07:26 (55 flights) and 08:10 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:45134 flights40.2%
Departs 07:2655 flights16.5%
Departs 08:1035 flights10.5%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

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 4 points worse at 85.1%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

OO 3977 next to LEX to DTW

Every carrier on LEX to DTW combined arrived on time 82.6% of the time across 786 flights, so OO 3977 is 3 points ahead of it. SkyWest flew 521 flights on the same city pair under all its flight numbers, including this one, and those ran 82.9% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 6 points.

OO 3977 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 3977thin sample	333	85.1%	95 min	1.20%	A
All SkyWest Airlines on LEX–DTW	521	82.9%	120 min	1.34%	B
All carriers on LEX–DTW	786	82.6%	109 min	1.15%	B
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	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 83 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 202585 flights81.2%
Oct–Dec 202578 flights88.2%
Jan–Mar 202682 flights77.5%
Apr–Jun 202688 flights93.2%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, OO 3977 ranged from 79.2% on Sunday to 89.8% on Thursday. With about 48 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why OO 3977 runs late

One category carries most of the weight here. Carrier accounts for 76% of the 4,662 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
76%
Extreme weather
19%
National Airspace System
5%

Extreme weather accounts for 19% 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 3.1 times the usual weather exposure. The split is drawn from 4,662 delay minutes reported on OO 3977.

Cancellations sit at 1.20% against a national 1.81%, 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 8.1%. That is the figure that decides a connection, and it says 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 same number turns up on three other city pairs in the data, including ELM to DTW (16), HSV to DTW (1) and DTW to HSV (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. 333 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: 85.1% on time and 1.20% cancelled. That is a base rate, not a promise about any single day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures