Flight profile · Frontier Airlines
F91279
Miami (MIA) to Denver (DEN) · scheduled 6:00 AM – 8:21 AM
How F91279 performs
680 operations, November 2023 – July 2026.
F91279 arrived on time 81.9% of the time, against 75.1% for all MIA → DEN flights, so this departure is 6.8 percentage points better than the route as a whole. Against Frontier Airlines’ own flights on this route it is 7.8 points better.
Source: US DOT Bureau of Transportation Statistics · 680 operations, November 2023 – July 2026 · If F91279 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where F91279 is right now
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| F91279 | 81.9% | 1.18% | -9 min | 7.3% | 680 |
| Frontier Airlines on MIA → DEN | 74.1% | 1.35% | -4 min | 10.3% | 1,181 |
| All MIA → DEN flights | 75.1% | 0.74% | -5 min | 9.0% | 7,698 |
Source: FlyerIntel analysis of US DOT BTS data · November 2023 – July 2026
Why F91279 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 F91279 on MIA → DEN. 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 F91279 comes in late, and what that does to the departure.
When the aircraft came in 15 or more minutes late, F91279 pushed back an average of 21 minutes late; when it came in on time or early, an average of 3 minutes late.
Each departure is matched to the flight the same aircraft flew into MIA just before it, using the tail number in the DOT file, 529 of 673 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 |
|---|---|---|---|
| F91279 | 36% | 31% | 11% |
| Network, same turn | 33% | 24% | 11% |
The schedule leaves a long gap on the ground, which gives a late aircraft room to catch up before this flight pushes back.
The network row is every flight with a scheduled turn of 3 to 6 hours. How often F91279’s aircraft landed 15 or more minutes late is about the same as the network’s and, once the aircraft was late, how often F91279 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 MIA late, does that still matter by the time it reaches DEN?
F91279 pushes back an average of 16.3 minutes late and reaches the gate at DEN an average of 7.9 minutes late. The 8.4 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 19.7 minutes on the taxiways at MIA, 1.7 minutes longer than a typical MIA departure in the same hour.
On arrival at DEN, F91279 spends 14.3 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 4.5 minutes longer than a typical DEN arrival (9.8 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 DEN. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 15,120 departures from MIA scheduled in the clock hour F91279 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at DEN (963,027 flights), not just F91279’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · November 2023 – July 2026
The hour it leaves MIA
Part of any flight’s record belongs to the clock rather than to the flight. F91279 has one departure time, so this is what that time is worth.
On-time arrival rate. 15,120 departures from MIA are scheduled in the 6 AM–7 AM hour over the period, against 340,469 across the whole day.
F91279 is scheduled out of MIA at 6:00 AM, in the 6 AM–7 AM bank. Departures from MIA in that hour arrive on time 89.6% of the time against 73.2% across the airport’s whole day — the slot alone is worth 16.4 points better before anything about this particular flight is considered.
The two airport figures cover every departure from MIA 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.
Other routes F91279 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 |
|---|---|---|---|
| CLE→MCO Cleveland to Orlando | August 29, 2023 | 1 | — |
Because the same number has served different journeys, the statistics above describe only the route F91279 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.
36 min late
against a median of 9 min early
Percentiles over 680 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering November 2023 – July 2026
Data and methodology
Calculated by FlyerIntel from 680 records of F91279 operating MIA → DEN, 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
Analysis last recomputed