Flight profile · SkyWest Airlines
OO4803
Milwaukee (MKE) to Chicago (ORD) · scheduled 7:00 AM – 8:05 AM
How OO4803 performs
1,001 operations, September 2023 – July 2026.
OO4803 arrived on time 81.1% of the time, against 72.4% for all MKE → ORD flights, so this departure is 8.7 percentage points better than the route as a whole. Against SkyWest Airlines’ own flights on this route it is 9.0 points better.
Source: US DOT Bureau of Transportation Statistics · 1,001 operations, September 2023 – July 2026 · If OO4803 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where OO4803 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| OO4803 | 81.1% | 1.50% | -6 min | 10.5% | 1,001 |
| SkyWest Airlines on MKE → ORD | 72.1% | 2.78% | -3 min | 12.5% | 10,528 |
| All MKE → ORD flights | 72.4% | 2.91% | -3 min | 12.3% | 11,098 |
OO4803 has cancelled 1.50% of its scheduled departures (15 of 1,001), against 2.91% for all MKE → ORD flights — this specific departure cancels 1.4 percentage points less often than the route as a whole. Different flight numbers on the same route can carry different aircraft, crews and schedules, so this is a fact about OO4803 specifically, not about the route it flies.
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026
Why OO4803 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for OO4803 on MKE → ORD. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies OO4803 comes in late, and what that does to the departure.
OO4803 is usually the aircraft’s first flight of the day: the schedule gives it a median of 9.5 hours on the ground at MKE, so its “inbound” is mostly the aircraft’s arrival the evening before.
When the aircraft came in 15 or more minutes late, OO4803 pushed back an average of 28 minutes late; when it came in on time or early, an average of 5 minutes late.
Each departure is matched to the flight the same aircraft flew into MKE just before it, using the tail number in the DOT file, 842 of 986 departures in all. A departure is left out when that flight is unknown, was cancelled or diverted, or the aircraft had sat for more than 12 hours. A flight the airline cancelled never left and is not in the count, and one flown by a substitute aircraft is matched to the aircraft that flew it, not to the one first planned.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late | Left 15+ late after a late inbound | Left 15+ late after an on-time inbound |
|---|---|---|---|
| OO4803 | 27% | 25% | 10% |
| Network, same turn | 29% | 12% | 9% |
A night on the ground absorbs most of a late arrival, so a late inbound matters far less on a turn this long than on a same-day one.
The network row is every flight with a scheduled turn of 6 hours or more, usually overnight. How often OO4803’s aircraft landed 15 or more minutes late is about the same as the network’s and, once the aircraft was late, how often OO4803 left 15 or more minutes late is higher than the network’s.
More: Which Flight Numbers Pay for a Late Aircraft lists the flight numbers that pass a late aircraft on.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2023 – July 2026
From pushback to gate
When it leaves MKE late, does that still matter by the time it reaches ORD?
On arrival at ORD, OO4803 spends 19.5 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is 1.7 minutes longer than a typical ORD arrival (17.8 min).
Departure delay is averaged over every pushback and arrival delay over every completed arrival, so the two counts differ by the flights that never reached ORD. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 8,039 departures from MKE scheduled in the clock hour OO4803 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at ORD (952,666 flights), not just OO4803’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026
The hour it leaves MKE
Part of any flight’s record belongs to the clock rather than to the flight. OO4803 has one departure time, so this is what that time is worth.
On-time arrival rate. 8,039 departures from MKE are scheduled in the 7 AM–8 AM hour over the period, against 87,869 across the whole day.
OO4803 is scheduled out of MKE at 7:00 AM, in the 7 AM–8 AM bank. Departures from MKE in that hour arrive on time 86.8% of the time against 80.7% across the airport’s whole day — the slot alone is worth 6.1 points better before anything about this particular flight is considered.
The two airport figures cover every departure from MKE to every destination, so they describe the slot rather than this journey — the like-for-like comparison against the route is above. Hours are scheduled local, and a number whose schedule moved between banks inside the period has no single hour and is not described here at all. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026 · Hours below 120 departures are not scored.
By day of week
Does OO4803 run worse on particular days?
Wednesday is historically the most reliable day and Tuesday the least, a gap of 11.6 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026 · Days with fewer than 120 operations are not scored.
Other routes OO4803 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| AMA→IAH Amarillo to Houston | March 30, 2025 – April 30, 2025 | 32 | — |
| LIT→ORD Little Rock to Chicago | December 3, 2024 | 1 | — |
| ORD→CRW Chicago to Charleston | September 5–28, 2023 | 24 | — |
| SUN→SFO Hailey to San Francisco | July 3, 2023 – September 4, 2023 | 46 | — |
| DCA→ORD Washington to Chicago | August 5, 2023 – September 3, 2023 | 10 | — |
| EUG→SFO Eugene to San Francisco | July 1–30, 2023 | 10 | — |
Because the same number has served different journeys, the statistics above describe only the route OO4803 currently operates. Blending them would produce an average of two different flights.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
64 min late
against a median of 6 min early
OO4803 has an average that understates its risk: a typical arrival is 6 min early, but the worst tenth are 70 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 1,001 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2023 – July 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| OO5799 | SkyWest Airlines | 85.5% | 19 min early | 718 |
| OO4803 this flight | SkyWest Airlines | 81.1% | 6 min early | 1,001 |
| OO5402 | SkyWest Airlines | 74.7% | 1 min early | 1,058 |
| OO4740 | SkyWest Airlines | 74.1% | 1 min early | 960 |
| OO5648 | SkyWest Airlines | 58.3% | 9 min late | 894 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. OO4803 is placed in the same ordering rather than left out of it; the rows around it are the most punctual departures on the route, not all of them, so this is a comparison and not a rank. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 1,001 records of OO4803 operating MKE → ORD, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
Full methodology · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
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