Flight number record

AA 1666

American Airlines · Phoenix to Ontario

Route: PHX → ONT
Departs: 16:58
Flights: 270
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AA 1666, check with American Airlines.

AA 1666 sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 270 flights, with a median arrival 6 minutes early.

On time

75.3%

Arrivals under 15 minutes late, of 267 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

1.11%

National rate is 1.81%

1 hour+ late

10.1%

National rate is 8.1%

These figures cover 270 flights between July 2025 and June 2026. Beyond the headline rate, 10.1% 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 AA 1666 flies

AA 1666 flies PHX to ONT without a single fixed slot. Its most common scheduled departure was 16:58, used on 61 of 270 flights, with 18:03 (44 flights) and 18:05 (38 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 16:5861 flights22.6%
Departs 18:0344 flights16.3%
Departs 18:0538 flights14.1%

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 16:58 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and AA 1666 runs 3 points better at 75.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

AA 1666 next to PHX to ONT

Every carrier on PHX to ONT combined arrived on time 77.7% of the time across 3,059 flights, so AA 1666 is 2 points behind it. American flew 1,315 flights on the same city pair under all its flight numbers, including this one, and those ran 80.4% on time. Across its whole network American Airlines managed 74.4%, close to this flight's figure.

AA 1666 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AA 1666thin sample	270	75.3%	60 min	1.11%	B
All American Airlines on PHX–ONT	1,315	80.4%	67 min	0.91%	B+
All carriers on PHX–ONT	3,059	77.7%	56 min	0.52%	B+
American Airlines, whole network	986,297	74.4%	85 min	2.29%	C

Across the year

AA 1666 quarter by quarter

Quarter by quarter AA 1666 held fairly steady: 80.0% in Jul–Sep 2025, 75.9% in Oct–Dec 2025 and 71.9% in Jan–Mar 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202586 flights80.0%
Oct–Dec 202588 flights75.9%
Jan–Mar 202690 flights71.9%
Apr–Jun 20266 flights—

Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, AA 1666 did best on Tuesday at 84.2% on time and worst on Friday at 63.2%. Each day rests on about 39 flights, so a gap of 21 points is worth noticing but could still narrow in another year.

Delay causes

Why AA 1666 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 82% of the 3,987 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.

Late-arriving aircraft
82%
Carrier
15%
National Airspace System
2%
Extreme weather
1%

82% 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 3,987 reported delay minutes here, that single category outweighs weather by 82 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 3,987 delay minutes reported on AA 1666.

Cancellations sit at 1.11% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

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. 10.1% 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 same number turns up on four other city pairs in the data, including ONT to PHX (143), ORD to LAX (44) and CHS to CLT (35), but none flew often enough under AA 1666 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to PHX to ONT only.

One caution: this is a thin sample. 270 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 1666

For a booking, read AA 1666 as 75.3% on time with 1.11% cancelled over 270 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures