Flight number record

OO 5911

SkyWest Airlines · Helena to Denver

Route: HLN → DEN
Departs: 14:30
Flights: 364
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 5911, 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 5911 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 close to two hours behind schedule. That rests on 364 flights, with a median arrival 6 minutes early.

On time

75.3%

Arrivals under 15 minutes late, of 356 completed flights

Avg delay

111 min

Across delayed arrivals only, not all flights

Cancelled

0.27%

National rate is 1.81%

1 hour+ late

13.8%

National rate is 8.1%

These figures cover 364 flights between July 2025 and June 2026. Beyond the headline rate, 13.8% 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 5911 flies

OO 5911 flies HLN to DEN without a single fixed slot. Its most common scheduled departure was 14:30, used on 98 of 364 flights, with 14:25 (53 flights) and 14:34 (49 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 14:3098 flights26.9%
Departs 14:2553 flights14.6%
Departs 14:3449 flights13.5%

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 14:30 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and OO 5911 runs 3 points better at 75.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

OO 5911 next to HLN to DEN

Every carrier on HLN to DEN combined arrived on time 78.9% of the time across 844 flights, so OO 5911 is 4 points behind it. Across its whole network SkyWest Airlines managed 79.0%, which this flight trails by 4 points.

OO 5911 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 5911thin sample	364	75.3%	111 min	0.27%	B+
All SkyWest Airlines on HLN–DEN	844	78.9%	105 min	0.71%	B+
All carriers on HLN–DEN	844	78.9%	105 min	0.71%	B+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 5911 quarter by quarter

OO 5911 did not run the same all year. Its best quarter was Jan–Mar 2026 at 86.7% on time and its weakest Jul–Sep 2025 at 50.0%, a swing of 37 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 flights50.0%
Oct–Dec 202591 flights82.2%
Jan–Mar 202690 flights86.7%
Apr–Jun 202691 flights81.1%

Scale runs 40% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, OO 5911 did best on Sunday at 86.5% on time and worst on Wednesday at 70.0%. Each day rests on about 52 flights, so a gap of 17 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 5911 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 9,751 reported delay minutes.

Carrier
30%
National Airspace System
26%
Late-arriving aircraft
25%
Extreme weather
19%

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 3.0 times the usual weather exposure. The split is drawn from 9,751 delay minutes reported on OO 5911.

Cancellations are rare at 0.27%, 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. 13.8% 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.

The 594 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

Every one of the 364 flights under OO 5911 in the data flew HLN to DEN. 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. 364 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 5911

For a booking, OO 5911 is a flight to put a long connection behind. 13.8% 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