Flight number record
F9 4211
Frontier Airlines · Atlanta to Austin
- Route
- ATL → AUS
- Departs
- 15:23
- Flights
- 259
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s F9 4211, check with Frontier Airlines.
F9 4211 draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 259 flights, with a median arrival right on schedule.
The national on-time rate over the same period is 77.6%, so F9 4211 runs 12 points behind the country as a whole. Across a thousand flights that is about 116 extra late arrivals.
Key figures
On time
66.0%
Arrivals under 15 minutes late, of 250 completed flights
Avg delay
77 min
Across delayed arrivals only, not all flights
Cancelled
3.47%
National rate is 1.81%
1 hour+ late
12.0%
National rate is 8.1%
These figures cover 259 flights between July 2025 and June 2026. Beyond the headline rate, 12.0% 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 F9 4211 flies
F9 4211 flies ATL to AUS without a single fixed slot. Its most common scheduled departure was 15:23, used on 39 of 259 flights. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 15:2339 flights15.1%
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 15:23 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and F9 4211 runs 6 points worse at 66.0%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
F9 4211 next to ATL to AUS
Every carrier on ATL to AUS combined arrived on time 79.8% of the time across 4,545 flights, so F9 4211 is 14 points behind it. Across its whole network Frontier Airlines managed 73.2%, which this flight trails by 7 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| F9 4211thin sample | 259 | 66.0% | 77 min | 3.47% | C− |
| All Frontier Airlines on ATL–AUSthin sample | 275 | 66.5% | 78 min | 3.27% | C− |
| All carriers on ATL–AUS | 4,545 | 79.8% | 58 min | 1.39% | B |
| Frontier Airlines, whole network | 205,332 | 73.2% | 84 min | 1.85% | C |
Across the year
F9 4211 quarter by quarter
F9 4211 did not run the same all year. Its best quarter was Jan–Mar 2026 at 78.7% on time and its weakest Jul–Sep 2025 at 54.7%, a swing of 24 points on roughly 65 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 202559 flights54.7%
- Oct–Dec 202556 flights60.0%
- Jan–Mar 202662 flights78.7%
- Apr–Jun 202682 flights67.9%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, F9 4211 did best on Thursday at 83.3% on time and worst on Saturday at 53.3%. Each day rests on about 37 flights, so a gap of 30 points is worth noticing but could still narrow in another year.
Delay causes
Why F9 4211 runs late
One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 6,522 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.
- 45%Late-arriving aircraft
- 31%Carrier
- 22%National Airspace System
- 1%Extreme weather
45% 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 6,522 reported delay minutes here, that single category outweighs weather by 45 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 6,522 delay minutes reported on F9 4211.
Cancellations run at 3.47%, against 1.81% nationally. That is about one flight in 30 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. 12.0% 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.
The 813 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
Every one of the 259 flights under F9 4211 in the data flew ATL to AUS. 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. 259 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 F9 4211
For a booking, the cancellation rate is the figure to plan around on F9 4211: 3.47% of its 259 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
- ATL to AUS, every carrier and departure
- AUS to ATL, the return direction
- Delta Air Lines 2976 on the same route93.2%
- Delta Air Lines 2886 on the same route86.9%
- Delta Air Lines 1397 on the same route77.5%
- Delta Air Lines 1491 on the same route74.4%
- Delta Air Lines 2104 on the same route84.2%
- Delta Air Lines 1170 on the same route70.9%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Austin-Bergstrom International (AUS) delay statistics
- Frontier Airlines on-time record
- Every Frontier Airlines 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 Frontier 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.