Flight profile · Frontier Airlines
F91448
San Francisco (SFO) to Atlanta (ATL) · scheduled 10:29 PM – 6:15 AM
How F91448 performs
790 operations, November 2023 – July 2026.
F91448 arrived on time 58.6% of the time, against 81.1% for all SFO → ATL flights, so this departure is 22.5 percentage points worse than the route as a whole. Against Frontier Airlines’ own flights on this route it is 1.0 points worse.
Source: US DOT Bureau of Transportation Statistics · 790 operations, November 2023 – July 2026 · If F91448 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
What stands out
How F91448 compares to other flight numbers, not just to itself.
This flight runs unusually far behind the SFO → ATL route as a whole, worse than 98% of 11,788 comparable flight numbers.
58.6% on time for this specific departure, against 81.1% for every SFO → ATL flight.
Source: FlyerIntel analysis of US DOT BTS data · November 2023 – July 2026 · The one thing about this specific departure that ranks most extreme against every other published flight number, out of everything FlyerIntel checks — shown only when something clears a real statistical bar, not for every flight.
Where F91448 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 |
|---|---|---|---|---|---|
| F91448 | 58.6% | 2.78% | 8 min | 15.8% | 790 |
| Frontier Airlines on SFO → ATL | 59.6% | 3.30% | 8 min | 15.5% | 940 |
| All SFO → ATL flights | 81.1% | 0.94% | -7 min | 5.7% | 10,070 |
F91448 has cancelled 2.78% of its scheduled departures (22 of 790), against 0.94% for all SFO → ATL flights — this specific departure cancels 1.8 percentage points more 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 F91448 specifically, not about the route it flies.
Source: FlyerIntel analysis of US DOT BTS data · November 2023 – July 2026
Why F91448 runs late
Where US DOT attributed the delay minutes on this flight.
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
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 F91448 on SFO → ATL. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering November 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies F91448 comes in late, and what that does to the departure.
When the aircraft came in 15 or more minutes late, F91448 pushed back an average of 65 minutes late; when it came in on time or early, an average of 7 minutes late.
Each departure is matched to the flight the same aircraft flew into SFO just before it, using the tail number in the DOT file, 752 of 769 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 |
|---|---|---|---|
| F91448 | 42% | 80% | 19% |
| Network, same turn | 17% | 68% | 9% |
The schedule leaves a normal turn: enough time to clean and board if the aircraft is on time, little to spare if it is not.
The network row is every flight with a scheduled turn of 60 to 89 minutes. How often F91448’s aircraft landed 15 or more minutes late is higher than the network’s and, once the aircraft was late, how often F91448 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 November 2023 – July 2026
From pushback to gate
When it leaves SFO late, does that still matter by the time it reaches ATL?
F91448 pushes back an average of 35.2 minutes late and reaches the gate at ATL an average of 28.1 minutes late. The 7.1 minutes between those two figures are slack the published schedule already carries, which is why a late pushback on this flight does not reliably become a late arrival. It spends 20.5 minutes on the taxiways at SFO, 1.2 minutes shorter than a typical SFO departure in the same hour.
On arrival at ATL, F91448 spends 18.5 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 9.0 minutes longer than a typical ATL arrival (9.6 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 ATL. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 25,191 departures from SFO scheduled in the clock hour F91448 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at ATL (1,012,161 flights), not just F91448’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · November 2023 – July 2026
The hour it leaves SFO
Part of any flight’s record belongs to the clock rather than to the flight. F91448 has one departure time, so this is what that time is worth.
On-time arrival rate. 25,191 departures from SFO are scheduled in the 10 PM–11 PM hour over the period, against 435,779 across the whole day.
F91448 is scheduled out of SFO at 10:29 PM, in the 10 PM–11 PM bank. Departures from SFO in that hour arrive on time 79.1% of the time against 78.7% across the airport’s whole day, so the hour F91448 leaves in is an ordinary one for SFO and explains nothing about its record either way.
The two airport figures cover every departure from SFO 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 · November 2023 – July 2026 · Hours below 120 departures are not scored.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
83 min late
against a median of 8 min late
F91448 has an average that understates its risk: a typical arrival is 8 min late, but the worst tenth are 75 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 790 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering November 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 |
|---|---|---|---|---|
| DL570 | Delta Air Lines | 92.4% | 10 min early | 785 |
| DL640 | Delta Air Lines | 89.2% | 10 min early | 784 |
| DL690 | Delta Air Lines | 80.9% | 5 min early | 696 |
| F91448 this flight | Frontier Airlines | 58.6% | 8 min late | 790 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. F91448 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 790 records of F91448 operating SFO → ATL, 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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