Flight number record

OO 5499

SkyWest Airlines · Chicago to South Bend

Route: ORD → SBN
Departs: 19:35
Flights: 354
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 5499, 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 5499 earns a D−, which is as low as this site's scale goes for a reason. Only 55.5% of flights arrive inside the 15-minute window, 22 points worse than the national rate of 77.6%. Late arrivals average close to two hours. Treat any tight connection here as a coin flip. That rests on 354 flights, with a median arrival 11 minutes late.

The national on-time rate over the same period is 77.6%, so OO 5499 runs 22 points behind the country as a whole. Across a thousand flights that is about 221 extra late arrivals.

On time

55.5%

Arrivals under 15 minutes late, of 337 completed flights

Avg delay

102 min

Across delayed arrivals only, not all flights

Cancelled

3.95%

National rate is 1.81%

1 hour+ late

23.4%

National rate is 8.1%

These figures cover 354 flights between July 2025 and June 2026. Beyond the headline rate, 23.4% 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 5499 flies

OO 5499 flies ORD to SBN without a single fixed slot. Its most common scheduled departure was 19:35, used on 215 of 354 flights, with 19:45 (71 flights) and 19:40 (68 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 19:35215 flights60.7%
Departs 19:4571 flights20.1%
Departs 19:4068 flights19.2%

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 19:35 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and OO 5499 runs 13 points worse at 55.5%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

OO 5499 next to ORD to SBN

Every carrier on ORD to SBN combined arrived on time 62.7% of the time across 2,704 flights, so OO 5499 is 7 points behind it. SkyWest flew 2,692 flights on the same city pair under all its flight numbers, including this one, and those ran 62.5% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight trails by 24 points.

OO 5499 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 5499thin sample	354	55.5%	102 min	3.95%	D−
All SkyWest Airlines on ORD–SBN	2,692	62.5%	87 min	4.27%	D−
All carriers on ORD–SBN	2,704	62.7%	87 min	4.25%	D−
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 5499 quarter by quarter

OO 5499 did not run the same all year. Its best quarter was Apr–Jun 2026 at 72.9% on time and its weakest Jan–Mar 2026 at 42.9%, a swing of 30 points on roughly 89 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 202588 flights48.2%
Oct–Dec 202585 flights57.8%
Jan–Mar 202690 flights42.9%
Apr–Jun 202691 flights72.9%

Scale runs 35% to 80%. Rows with fewer than 30 flights show a dash.

By weekday, OO 5499 did best on Wednesday at 64.4% on time and worst on Saturday at 42.2%. Each day rests on about 51 flights, so a gap of 22 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 5499 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 58% of the 15,000 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
58%
Carrier
22%
National Airspace System
13%
Extreme weather
7%

58% 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 15,000 reported delay minutes here, that single category outweighs weather by 9 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 15,320 delay minutes reported on OO 5499.

Cancellations run at 3.95%, against 1.81% nationally. That is about one flight in 25 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

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. 23.4% 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 354 flights under OO 5499 in the data flew ORD to SBN. 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. 354 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 5499

For a booking, the cancellation rate is the figure to plan around on OO 5499: 3.95% of its 354 scheduled flights did not operate. A late arrival costs close to two hours, but a cancellation costs the day, so leave a later option open.

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