Flight number record
MQ 4321
Envoy Air · Chicago to Waterloo
- Route
- ORD → ALO
- Departs
- 22:34
- Flights
- 267
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s MQ 4321, check with Envoy Air. Envoy Air flies under contract for larger airlines, so a ticket for this flight may show a different airline code and number.
MQ 4321 sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 267 flights, with a median arrival 3 minutes early.
The national on-time rate over the same period is 77.3%, so MQ 4321 runs 9 points behind the country as a whole. Across a thousand flights that is about 86 extra late arrivals.
Key figures
On time
68.7%
Arrivals under 15 minutes late, of 252 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
4.87%
National rate is 1.89%
1 hour+ late
13.5%
National rate is 8.3%
These figures cover 267 flights between September 2025 and August 2026. Beyond the headline rate, 13.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When MQ 4321 flies
MQ 4321 flies ORD to ALO without a single fixed slot. Its most common scheduled departure was 22:34, used on 54 of 267 flights, with 22:27 (46 flights) and 21:07 (36 flights) next.
- Departs 22:3454 flights20.2%
- Departs 22:2746 flights17.2%
- Departs 21:0736 flights13.5%
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 22:34 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and MQ 4321 runs level with that at 68.7%. 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
MQ 4321 next to ORD to ALO
Every carrier on ORD to ALO combined arrived on time 71.8% of the time across 654 flights, so MQ 4321 is 3 points behind it. Envoy flew 500 flights on the same city pair under all its flight numbers, including this one, and those ran 73.4% on time. Across its whole network Envoy Air managed 81.0%, which this flight trails by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| MQ 4321thin sample | 267 | 68.7% | 70 min | 4.87% | C− |
| All Envoy Air on ORD–ALO | 500 | 73.4% | 75 min | 3.00% | C |
| All carriers on ORD–ALO | 654 | 71.8% | 89 min | 4.59% | C− |
| Envoy Air, whole network | 320,362 | 81.0% | 70 min | 2.19% | B |
Across the year
MQ 4321 quarter by quarter
Quarter by quarter MQ 4321 held fairly steady: 70.0% in Oct–Dec 2025, 69.8% in Jan–Mar 2026 and 64.4% in Apr–Jun 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202527 flights—
- Oct–Dec 202588 flights70.0%
- Jan–Mar 202689 flights69.8%
- Apr–Jun 202663 flights64.4%
Scale runs 55% to 75%. Rows with fewer than 30 flights show a dash.
By weekday, MQ 4321 did best on Saturday at 82.9% on time and worst on Thursday at 54.3%. Each day rests on about 38 flights, so a gap of 29 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late MQ 4321 runs when it is late
The 79 late arrivals split 24 under half an hour, 21 between 30 and 60 minutes, and 34 an hour or more.
- 15+ min early55 flights21.8%
- Within 15 min118 flights46.8%
- 15–29 min late24 flights9.5%
- 30–59 min late21 flights8.3%
- 1–2 hours late23 flights9.1%
- 2+ hours late11 flights4.4%
Scale runs 0% to 100%.
Share of 252 completed flights by arrival against schedule.
10 of 76 late departures made up the time and arrived on time, 13% of them. In the other direction, 13 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 ALO.
The worst days
Worst days for MQ 4321
The latest arrival of the period was on 28 January 2026, 9 hours 26 minutes behind schedule; most of its delay minutes were filed as extreme weather. The five worst days are spread across January, December and April, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 January 2026 | 9 hours 26 minutes | Extreme weather |
| 30 December 2025 | 4 hours 15 minutes | Extreme weather |
| 3 December 2025 | 4 hours 2 minutes | National Airspace System |
| 27 April 2026 | 3 hours 19 minutes | Late-arriving aircraft |
| 14 April 2026 | 3 hours 3 minutes | Late-arriving aircraft |
Delay causes
Why MQ 4321 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 5,505 reported delay minutes.
- 40%Late-arriving aircraft
- 25%Extreme weather
- 19%National Airspace System
- 16%Carrier
Extreme weather accounts for 25% 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 4.1 times the usual weather exposure. The split is drawn from 5,505 delay minutes reported on MQ 4321.
Cancellations run at 4.87%, against 1.89% nationally. That is about one flight in twenty 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
13.5% 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 same number turns up on one other city pair in the data, including ORD to MSN (28), but none flew often enough under MQ 4321 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ORD to ALO only.
One caution: this is a thin sample. 267 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 MQ 4321
For a booking, the cancellation rate is the figure to plan around on MQ 4321: 4.87% of its 267 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- Chicago O'Hare International (ORD) delay statistics
- Envoy Air on-time record
- Every Envoy Air flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Envoy Air’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.