Flight number record

OO 5421

SkyWest Airlines · Denver to Lubbock

Route: DEN → LBB
Departs: 13:50
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 5421, 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 5421 sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 365 flights, with a median arrival 7 minutes early.

On time

75.4%

Arrivals under 15 minutes late, of 362 completed flights

Avg delay

94 min

Across delayed arrivals only, not all flights

Cancelled

0.55%

National rate is 1.81%

1 hour+ late

13.5%

National rate is 8.1%

These figures cover 365 flights between July 2025 and June 2026. Beyond the headline rate, 13.5% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Schedule

When OO 5421 flies

OO 5421 flies DEN to LBB without a single fixed slot. Its most common scheduled departure was 13:50, used on 98 of 365 flights, with 14:00 (68 flights) and 14:10 (47 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 13:5098 flights26.8%
Departs 14:0068 flights18.6%
Departs 14:1047 flights12.9%

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 13:50 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and OO 5421 runs 3 points worse at 75.4%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

OO 5421 next to DEN to LBB

Every carrier on DEN to LBB combined arrived on time 71.9% of the time across 977 flights, so OO 5421 is 4 points ahead of it. SkyWest flew 707 flights on the same city pair under all its flight numbers, including this one, and those ran 73.7% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight trails by 4 points.

OO 5421 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 5421	365	75.4%	94 min	0.55%	B+
All SkyWest Airlines on DEN–LBB	707	73.7%	102 min	1.56%	C
All carriers on DEN–LBB	977	71.9%	93 min	1.54%	C
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 5421 quarter by quarter

OO 5421 did not run the same all year. Its best quarter was Oct–Dec 2025 at 84.8% on time and its weakest Jan–Mar 2026 at 70.1%, a swing of 15 points on roughly 91 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 202592 flights70.7%
Oct–Dec 202592 flights84.8%
Jan–Mar 202690 flights70.1%
Apr–Jun 202691 flights75.8%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, OO 5421 ranged from 70.6% on Sunday to 81.1% on Tuesday. With about 52 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 5421 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 51% of the 8,382 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.

Late-arriving aircraft
51%
Carrier
34%
National Airspace System
11%
Extreme weather
5%

51% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 8,382 reported delay minutes here, that single category outweighs weather by 10 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 8,382 delay minutes reported on OO 5421.

Cancellations are rare at 0.55%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 13.5% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

Every one of the 365 flights under OO 5421 in the data flew DEN to LBB. 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. 365 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 5421

For a booking, OO 5421 is a flight to put a long connection behind. 13.5% 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.

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