Flight number record

UA 1873

United Airlines · Phoenix to Washington

Route: PHX → IAD
Departs: 09:00
Flights: 316
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1873, check with United Airlines.

UA 1873 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 15 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 316 flights, with a median arrival 12 minutes early.

Set against the rest of the country, UA 1873's record is 15 points better than the US average of 77.6%. That gap is worth roughly 148 fewer late arrivals for every thousand flights.

On time

92.4%

Arrivals under 15 minutes late, of 314 completed flights

Avg delay

75 min

Across delayed arrivals only, not all flights

Cancelled

0.32%

National rate is 1.81%

1 hour+ late

2.2%

National rate is 8.1%

These figures cover 316 flights between July 2025 and June 2026. The median arrival is 12 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Schedule

When UA 1873 flies

UA 1873 flies PHX to IAD without a single fixed slot. Its most common scheduled departure was 09:00, used on 49 of 316 flights, with 08:00 (44 flights) and 08:50 (42 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 09:0049 flights15.5%
Departs 08:0044 flights13.9%
Departs 08:5042 flights13.3%

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 09:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 1873 runs 8 points better at 92.4%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

UA 1873 next to PHX to IAD

Every carrier on PHX to IAD combined arrived on time 84.7% of the time across 1,098 flights, so UA 1873 is 8 points ahead of it. United flew 761 flights on the same city pair under all its flight numbers, including this one, and those ran 89.7% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 13 points.

UA 1873 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1873thin sample	316	92.4%	75 min	0.32%	A+
All United Airlines on PHX–IAD	761	89.7%	73 min	0.79%	A+
All carriers on PHX–IAD	1,098	84.7%	56 min	0.64%	B+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 1873 quarter by quarter

Quarter by quarter UA 1873 held fairly steady: 86.0% in Jul–Sep 2025, 91.3% in Oct–Dec 2025, 95.5% in Jan–Mar 2026 and 93.3% in Apr–Jun 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202543 flights86.0%
Oct–Dec 202592 flights91.3%
Jan–Mar 202690 flights95.5%
Apr–Jun 202691 flights93.3%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1873 ranged from 86.4% on Sunday to 97.7% on Wednesday. With about 45 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why UA 1873 runs late

One category carries most of the weight here. Carrier accounts for 46% of the 1,806 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.

Carrier
46%
Late-arriving aircraft
42%
National Airspace System
13%

42% 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 1,806 reported delay minutes here, that single category outweighs weather by 42 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 1,806 delay minutes reported on UA 1873.

Cancellations are rare at 0.32%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 2.2% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 1,956 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.

The same number turns up on three other city pairs in the data, including SEA to IAD (49), IAD to CLE (24) and IAD to DTW (18), but none flew often enough under UA 1873 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to PHX to IAD only.

One caution: this is a thin sample. 316 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 UA 1873

For a booking, UA 1873 has one of the better records a US domestic flight can show: 92.4% on time and 0.32% cancelled. That is a base rate, not a promise about any single day.

Where to go next

A flight number here means United 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