Flight number record
AA 12
American Airlines · Los Angeles to Boston
- Route
- LAX → BOS
- Departs
- 08:00
- Flights
- 364
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AA 12, check with American Airlines.
AA 12 lands a B, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 364 flights, with a median arrival 7 minutes early.
Key figures
On time
78.8%
Arrivals under 15 minutes late, of 359 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
1.37%
National rate is 1.89%
1 hour+ late
9.5%
National rate is 8.3%
These figures cover 364 flights between September 2025 and August 2026. Beyond the headline rate, 9.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When AA 12 flies
AA 12 flies LAX to BOS without a single fixed slot. Its most common scheduled departure was 08:00, used on 97 of 364 flights, with 08:30 (52 flights) and 08:15 (43 flights) next.
- Departs 08:0097 flights26.6%
- Departs 08:3052 flights14.3%
- Departs 08:1543 flights11.8%
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 08:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and AA 12 runs 5 points worse at 78.8%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
AA 12 next to LAX to BOS
Every carrier on LAX to BOS combined arrived on time 76.2% of the time across 4,797 flights, so AA 12 is 3 points ahead of it. American flew 1,184 flights on the same city pair under all its flight numbers, including this one, and those ran 74.1% on time. Across its whole network American Airlines managed 74.7%, which this flight beats by 4 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AA 12thin sample | 364 | 78.8% | 76 min | 1.37% | B |
| All American Airlines on LAX–BOS | 1,184 | 74.1% | 94 min | 1.60% | C |
| All carriers on LAX–BOS | 4,797 | 76.2% | 80 min | 1.81% | B |
| American Airlines, whole network | 988,892 | 74.7% | 85 min | 2.14% | C |
Across the year
AA 12 quarter by quarter
AA 12 did not run the same all year. Its best quarter was Jan–Mar 2026 at 87.4% on time and its weakest Jul–Sep 2025 at 60.0%, a swing of 27 points on roughly 73 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 202530 flights60.0%
- Oct–Dec 202592 flights76.1%
- Jan–Mar 202690 flights87.4%
- Apr–Jun 202690 flights77.5%
- Jul–Sep 202662 flights82.0%
Scale runs 50% to 95%.
By weekday, AA 12 did best on Tuesday at 84.0% on time and worst on Monday at 71.2%. Each day rests on about 52 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AA 12 runs when it is late
AA 12 often beats the schedule: 140 of 359 completed flights, 39%, arrived 15 minutes or more early. The 76 late arrivals split 20 under half an hour, 22 between 30 and 60 minutes, and 34 an hour or more.
- 15+ min early140 flights39.0%
- Within 15 min143 flights39.8%
- 15–29 min late20 flights5.6%
- 30–59 min late22 flights6.1%
- 1–2 hours late21 flights5.8%
- 2+ hours late13 flights3.6%
Scale runs 0% to 100%.
Share of 359 completed flights by arrival against schedule.
14 of 71 late departures made up the time and arrived on time, 20% of them. In the other direction, 19 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 BOS.
The worst days
Worst days for AA 12
The latest arrival of the period was on 17 October 2025, 7 hours 9 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 17 October 2025 | 7 hours 9 minutes | Carrier |
| 28 December 2025 | 5 hours 41 minutes | Late-arriving aircraft |
| 1 January 2026 | 5 hours 2 minutes | Carrier |
| 29 July 2026 | 4 hours 32 minutes | Carrier |
| 7 September 2025 | 4 hours 19 minutes | Carrier |
Delay causes
Why AA 12 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 5,753 reported delay minutes.
- 41%Carrier
- 33%National Airspace System
- 25%Late-arriving aircraft
- 0%Extreme weather
The largest share of delay minutes, 41%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,376 of the 5,753 delay minutes reported here. The split is drawn from 5,753 delay minutes reported on AA 12.
Cancellations sit at 1.37% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
9.5% 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.
At 2,611 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 364 flights under AA 12 in the data flew LAX to BOS. 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. 364 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 AA 12
For a booking, read AA 12 as 78.8% on time with 1.37% cancelled over 364 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- LAX to BOS, every carrier and departure
- BOS to LAX, the return direction
- Delta Air Lines 639 on the same route81.6%
- United Airlines 1783 on the same route82.0%
- American Airlines 2453 on the same route78.3%
- United Airlines 2210 on the same route90.7%
- Delta Air Lines 437 on the same route67.5%
- JetBlue Airways 988 on the same route78.4%
- Los Angeles International (LAX) delay statistics
- Boston Logan International (BOS) delay statistics
- American Airlines on-time record
- Every American Airlines flight number with a record
- The most and least reliable flight numbers in the US
- The best time of day to fly, according to 7.05 million flight records
A flight number here means American 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.