Flight number record
F9 3511
Frontier Airlines · Boston to Atlanta
- Route
- BOS → ATL
- Departs
- 12:01
- Flights
- 259
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s F9 3511, check with Frontier Airlines.
F9 3511 draws a D. Roughly 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 5 minutes late.
The national on-time rate over the same period is 77.3%, so F9 3511 runs 14 points behind the country as a whole. Across a thousand flights that is about 139 extra late arrivals.
Key figures
On time
63.4%
Arrivals under 15 minutes late, of 254 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
1.93%
National rate is 1.89%
1 hour+ late
12.6%
National rate is 8.3%
These figures cover 259 flights between September 2025 and August 2026. Beyond the headline rate, 12.6% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Schedule
When F9 3511 flies
F9 3511 flies BOS to ATL without a single fixed slot. Its most common scheduled departure was 12:01, used on 33 of 259 flights.
- Departs 12:0133 flights12.7%
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 12:01 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and F9 3511 runs 15 points worse at 63.4%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Against the route
F9 3511 next to BOS to ATL
Every carrier on BOS to ATL combined arrived on time 76.8% of the time across 5,050 flights, so F9 3511 is 13 points behind it. Frontier flew 453 flights on the same city pair under all its flight numbers, including this one, and those ran 62.6% on time. Across its whole network Frontier Airlines managed 72.7%, which this flight trails by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| F9 3511thin sample | 259 | 63.4% | 76 min | 1.93% | D |
| All Frontier Airlines on BOS–ATL | 453 | 62.6% | 62 min | 2.87% | D |
| All carriers on BOS–ATL | 5,050 | 76.8% | 72 min | 2.24% | B |
| Frontier Airlines, whole network | 213,022 | 72.7% | 84 min | 2.05% | C |
Across the year
F9 3511 quarter by quarter
F9 3511 did not run the same all year. Its best quarter was Apr–Jun 2026 at 73.0% on time and its weakest Jul–Sep 2026 at 50.8%, a swing of 22 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 202521 flights—
- Oct–Dec 202554 flights56.6%
- Jan–Mar 202631 flights63.3%
- Apr–Jun 202691 flights73.0%
- Jul–Sep 202662 flights50.8%
Scale runs 40% to 80%. Rows with fewer than 30 flights show a dash.
By weekday, F9 3511 did best on Thursday at 72.5% on time and worst on Sunday at 47.5%. Each day rests on about 37 flights, so a gap of 25 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late F9 3511 runs when it is late
The 93 late arrivals split 33 under half an hour, 28 between 30 and 60 minutes, and 32 an hour or more.
- 15+ min early63 flights24.8%
- Within 15 min98 flights38.6%
- 15–29 min late33 flights13.0%
- 30–59 min late28 flights11.0%
- 1–2 hours late22 flights8.7%
- 2+ hours late10 flights3.9%
Scale runs 0% to 100%.
Share of 254 completed flights by arrival against schedule.
18 of 81 late departures made up the time and arrived on time, 22% of them. In the other direction, 30 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 ATL.
The worst days
Worst days for F9 3511
The latest arrival of the period was on 5 August 2026, 22 hours 54 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in August 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 5 August 2026 | 22 hours 54 minutes | Carrier |
| 24 August 2026 | 7 hours 54 minutes | Late-arriving aircraft |
| 4 January 2026 | 4 hours 17 minutes | Late-arriving aircraft |
| 25 August 2026 | 4 hours 7 minutes | Late-arriving aircraft |
| 8 November 2025 | 3 hours 28 minutes | Late-arriving aircraft |
Delay causes
Why F9 3511 runs late
Late-arriving aircraft accounts for 46% of the 7,052 delay minutes carriers reported here, and the remaining four split what is left.
- 46%Late-arriving aircraft
- 31%Carrier
- 23%National Airspace System
- 1%Extreme weather
46% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 7,052 reported delay minutes here, that single category outweighs weather by 46 to one. The split is drawn from 7,052 delay minutes reported on F9 3511.
Cancellations sit at 1.93% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
12.6% 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 946 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.
Every one of the 259 flights under F9 3511 in the data flew BOS to ATL. 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 3511
For a booking, F9 3511 is a flight to put a long connection behind. 12.6% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- BOS to ATL, every carrier and departure
- ATL to BOS, the return direction
- Delta Air Lines 695 on the same route86.0%
- Delta Air Lines 322 on the same route78.0%
- Delta Air Lines 973 on the same route79.1%
- Delta Air Lines 456 on the same route89.4%
- Delta Air Lines 385 on the same route86.4%
- Delta Air Lines 923 on the same route87.2%
- Boston Logan International (BOS) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.