Flight number record

OO 3839

SkyWest Airlines · Salt Lake City to Helena

Route: SLC → HLN
Departs: 21:05
Flights: 255
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s OO 3839, 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 3839 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 18 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 35 minutes. That rests on 255 flights, with a median arrival 15 minutes early.

Set against the rest of the country, OO 3839's record is 18 points better than the US average of 77.3%. That gap is worth roughly 180 fewer late arrivals for every thousand flights.

On time

95.3%

Arrivals under 15 minutes late, of 255 completed flights

Avg delay

35 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.89%

1 hour+ late

0.4%

National rate is 8.3%

These figures cover 255 flights between September 2025 and August 2026. The median arrival is 15 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 3839 flies

OO 3839 flies SLC to HLN without a single fixed slot. Its most common scheduled departure was 21:05, used on 85 of 255 flights, with 20:55 (62 flights) and 21:00 (60 flights) next.

Departs 21:0585 flights33.3%
Departs 20:5562 flights24.3%
Departs 21:0060 flights23.5%

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 21:05 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and OO 3839 runs 25 points better at 95.3%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

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Against the route

OO 3839 next to SLC to HLN

Every carrier on SLC to HLN combined arrived on time 95.2% of the time across 725 flights, so OO 3839 is about level with it. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 17 points.

OO 3839 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 3839thin sample	255	95.3%	35 min	0.00%	A+
All SkyWest Airlines on SLC–HLN	725	95.2%	38 min	0.28%	A+
All carriers on SLC–HLN	725	95.2%	38 min	0.28%	A+
SkyWest Airlines, whole network	855,406	78.7%	88 min	1.79%	B

Across the year

OO 3839 quarter by quarter

Quarter by quarter OO 3839 held fairly steady: 94.4% in Jan–Mar 2026, 96.7% in Apr–Jun 2026 and 93.5% in Jul–Sep 2026. A spread of 3 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Oct–Dec 202512 flights—
Jan–Mar 202690 flights94.4%
Apr–Jun 202691 flights96.7%
Jul–Sep 202662 flights93.5%

Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, OO 3839 did best on Monday at 100.0% on time and worst on Thursday at 83.3%. Each day rests on about 36 flights, so a gap of 17 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late OO 3839 runs when it is late

OO 3839 often beats the schedule: 133 of 255 completed flights, 52%, arrived 15 minutes or more early. Most of the lateness is short. 7 of the 12 late arrivals were under half an hour behind, and 1 reached an hour or more.

15+ min early133 flights52.2%
Within 15 min110 flights43.1%
15–29 min late7 flights2.7%
30–59 min late4 flights1.6%
1–2 hours late0 flights0.0%
2+ hours late1 flights0.4%

Scale runs 0% to 100%.

Share of 255 completed flights by arrival against schedule.

Only 10 of 255 completed flights left 15 minutes late or more, too few to say how often the time is made up.

The worst days

Worst days for OO 3839

The latest arrival of the period was on 16 July 2026, 2 hours 14 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across July, March, June and January, with no single month standing out.

The latest arrivals of OO 3839 in the period
Date	Arrived late by	Largest filed cause
16 July 2026	2 hours 14 minutes	Carrier
14 March 2026	42 minutes	Carrier
19 June 2026	34 minutes	National Airspace System
21 July 2026	34 minutes	Extreme weather
15 January 2026	33 minutes	Extreme weather

Delay causes

Why OO 3839 runs late

Carrier accounts for 76% of the 425 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
76%
Extreme weather
13%
National Airspace System
11%

Extreme weather accounts for 13% 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 2.1 times the usual weather exposure. The split is drawn from 425 delay minutes reported on OO 3839.

Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 0.4% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The same number turns up on one other city pair in the data, including SMF to SEA (110), but none flew often enough under OO 3839 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SLC to HLN only.

One caution: this is a thin sample. 255 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 3839

For a booking, OO 3839 has one of the better records a US domestic flight can show: 95.3% on time and 0.00% 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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures