Flight number record
OO 5911
SkyWest Airlines · Helena to Denver
- Route
- HLN → DEN
- Departs
- 14:30
- Flights
- 363
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 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 lands a B+, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That rests on 363 flights, with a median arrival 10 minutes early.
Key figures
On time
79.8%
Arrivals under 15 minutes late, of 356 completed flights
Avg delay
107 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
1 hour+ late
10.4%
National rate is 8.3%
These figures cover 363 flights between September 2025 and August 2026. Beyond the headline rate, 10.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 85 of 363 flights, with 14:20 (81 flights) and 14:25 (53 flights) next.
- Departs 14:3085 flights23.4%
- Departs 14:2081 flights22.3%
- Departs 14:2553 flights14.6%
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 14:30 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and OO 5911 runs 8 points better at 79.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Against the route
OO 5911 next to HLN to DEN
Every carrier on HLN to DEN combined arrived on time 84.0% of the time across 783 flights, so OO 5911 is 4 points behind it. Across its whole network SkyWest Airlines managed 78.7%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 5911thin sample | 363 | 79.8% | 107 min | 0.55% | B+ |
| All SkyWest Airlines on HLN–DEN | 783 | 84.0% | 103 min | 0.38% | B+ |
| All carriers on HLN–DEN | 783 | 84.0% | 103 min | 0.38% | B+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | 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 2026 at 66.7%, a swing of 20 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 202530 flights—
- Oct–Dec 202591 flights82.2%
- Jan–Mar 202690 flights86.7%
- Apr–Jun 202691 flights81.1%
- Jul–Sep 202661 flights66.7%
Scale runs 60% 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 Saturday at 74.0%. Each day rests on about 52 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 5911 runs when it is late
OO 5911 often beats the schedule: 153 of 356 completed flights, 43%, arrived 15 minutes or more early. When OO 5911 is late it tends to be very late: 37 of its 72 late arrivals were an hour or more behind, and 24 were two hours or more.
- 15+ min early153 flights43.0%
- Within 15 min131 flights36.8%
- 15–29 min late19 flights5.3%
- 30–59 min late16 flights4.5%
- 1–2 hours late13 flights3.7%
- 2+ hours late24 flights6.7%
Scale runs 0% to 100%.
Share of 356 completed flights by arrival against schedule.
9 of 59 late departures made up the time and arrived on time, 15% of them. In the other direction, 22 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DEN.
The worst days
Worst days for OO 5911
The latest arrival of the period was on 8 May 2026, 9 hours 1 minute behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across May, December, November, March and August, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 8 May 2026 | 9 hours 1 minute | Carrier |
| 17 December 2025 | 7 hours 16 minutes | Extreme weather |
| 7 November 2025 | 6 hours 24 minutes | Carrier |
| 14 March 2026 | 4 hours 54 minutes | National Airspace System |
| 15 August 2026 | 4 hours 45 minutes | Extreme weather |
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 7,671 reported delay minutes.
- 32%Carrier
- 25%National Airspace System
- 22%Extreme weather
- 21%Late-arriving aircraft
Extreme weather accounts for 22% 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 3.6 times the usual weather exposure. The split is drawn from 7,671 delay minutes reported on OO 5911.
Cancellations are rare at 0.55%, below the national 1.89% 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
10.4% 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 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.
Every one of the 363 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. 363 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, read OO 5911 as 79.8% on time with 0.55% cancelled over 363 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- HLN to DEN, every carrier and departure
- DEN to HLN, the return direction
- Denver International (DEN) 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.