Flight number record
UA 1873
United Airlines · Phoenix to Washington
- Route
- PHX → IAD
- Departs
- 08:50
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 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 13 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 45 minutes. That rests on 365 flights, with a median arrival 10 minutes early.
Set against the rest of the country, UA 1873's record is 13 points better than the US average of 77.3%. That gap is worth roughly 133 fewer late arrivals for every thousand flights.
Key figures
On time
90.6%
Arrivals under 15 minutes late, of 361 completed flights
Avg delay
47 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
1 hour+ late
1.9%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 10 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.
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 UA 1873 flies
UA 1873 flies PHX to IAD without a single fixed slot. Its most common scheduled departure was 08:50, used on 83 of 365 flights, with 09:00 (49 flights) next.
- Departs 08:5083 flights22.7%
- Departs 09:0049 flights13.4%
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 08:50 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 1873 runs 7 points better at 90.6%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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
UA 1873 next to PHX to IAD
Every carrier on PHX to IAD combined arrived on time 86.1% of the time across 979 flights, so UA 1873 is 5 points ahead of it. United flew 704 flights on the same city pair under all its flight numbers, including this one, and those ran 90.8% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1873 | 365 | 90.6% | 47 min | 0.55% | A+ |
| All United Airlines on PHX–IAD | 704 | 90.8% | 57 min | 0.71% | A+ |
| All carriers on PHX–IAD | 979 | 86.1% | 45 min | 0.61% | A+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1873 quarter by quarter
UA 1873 did not run the same all year. Its best quarter was Jan–Mar 2026 at 95.5% on time and its weakest Jul–Sep 2026 at 80.0%, a swing of 16 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 flights86.7%
- Oct–Dec 202592 flights91.3%
- Jan–Mar 202690 flights95.5%
- Apr–Jun 202691 flights93.3%
- Jul–Sep 202662 flights80.0%
Scale runs 70% to 100%.
By weekday, UA 1873 ranged from 84.6% on Monday to 96.0% on Wednesday. With about 52 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.
Arrival by arrival
How late UA 1873 runs when it is late
UA 1873 often beats the schedule: 135 of 361 completed flights, 37%, arrived 15 minutes or more early. Most of the lateness is short. 19 of the 34 late arrivals were under half an hour behind, and 7 reached an hour or more.
- 15+ min early135 flights37.4%
- Within 15 min192 flights53.2%
- 15–29 min late19 flights5.3%
- 30–59 min late8 flights2.2%
- 1–2 hours late5 flights1.4%
- 2+ hours late2 flights0.6%
Scale runs 0% to 100%.
Share of 361 completed flights by arrival against schedule.
A late pushback is often recovered here: of 31 departures that left 15 minutes late or more, 13 still arrived on time. 16 flights left on time and still arrived late.
The worst days
Worst days for UA 1873
The latest arrival of the period was on 3 October 2025, 3 hours 54 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 3 October 2025 | 3 hours 54 minutes | Carrier |
| 14 June 2026 | 3 hours 45 minutes | Carrier |
| 1 September 2025 | 1 hour 46 minutes | Late-arriving aircraft |
| 10 November 2025 | 1 hour 45 minutes | Carrier |
| 18 July 2026 | 1 hour 45 minutes | National Airspace System |
Delay causes
Why UA 1873 runs late
Carrier accounts for 58% of the 1,609 delay minutes carriers reported here, and the remaining four split what is left.
- 58%Carrier
- 32%National Airspace System
- 10%Late-arriving aircraft
The largest share of delay minutes, 58%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 932 of the 1,609 delay minutes reported here. The split is drawn from 1,609 delay minutes reported on UA 1873.
Cancellations are rare at 0.55%, below the national 1.89% 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 1.9% land an hour or more behind schedule, against 8.3% 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 two other city pairs in the data, including 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. 365 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: 90.6% on time and 0.55% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- PHX to IAD, every carrier and departure
- IAD to PHX, the return direction
- Phoenix Sky Harbor International (PHX) delay statistics
- Washington Dulles International (IAD) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Worst months to fly in the US, ranked by the data
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.