Flight profile · United Airlines

UA721

Boston (BOS) to Washington (IAD) · scheduled 2:25 PM – 4:09 PM

FlyerIntel does not track flights in the air. This page describes how UA721 has historically performed, which is a different and more useful question when you are deciding what to book. For today’s status, check with United Airlines.

How UA721 performs

641 operations, 2024-05-23 to 2026-06-30.

On-time arrivals
74.1%
464 of 626 completed
Cancellation rate
2.03%
13 cancelled
Median arrival delay
0 min
Average 11.6 min
Severe delays
7.8%
Arrived 60+ minutes late
Delay when late
59 min
Average, when 15+ min late
Departure punctuality
85.3%
Left the gate on time

UA721 arrived on time 74.1% of the time, against 83.6% for all BOSIAD flights — this specific departure is 9.5 percentage points worse than the route as a whole. Against United Airlines’s own flights on this route it is 9.5 points worse.

Source: US DOT Bureau of Transportation Statistics · 641 operations between 2024-05-23 to 2026-06-30

Against the rest of the route

On timeCancelledMedian delaySevereFlights
UA72174.1%2.03%0 min7.8%641
United Airlines on BOSIAD83.6%1.28%-9 min6.1%4,464
All BOSIAD flights83.6%1.27%-9 min6.1%4,476

Source: FlyerIntel analysis of US DOT BTS data · 2024-05-23 to 2026-06-30

Other routes UA721 has flown

A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.

RouteOperatedFlightsOn time
IADLAS Washington to Las Vegas2026-02-122026-03-0418
ORDBOS Chicago to Boston2025-05-012025-08-189389.2%
JACSFO Jackson to San Francisco2025-08-022025-08-163
IAHSAT Houston to San Antonio2025-06-282025-07-265
IADMSY Washington to New Orleans2025-01-072025-02-1237
MSYLAX New Orleans to Los Angeles2025-02-062025-02-072
IAHBOS Houston to Boston2024-10-272024-12-0236
LAXIAH Los Angeles to Houston2024-10-272024-12-0236
EWRBOS Newark to Boston2023-07-012024-05-2230884.7%
TPAEWR Tampa to Newark2023-12-212024-01-0819
MCIEWR Kansas City to Newark2023-07-012023-09-0466

Because the same number has served different journeys, the statistics above describe only the route UA721 currently operates. Blending them would produce an average of two different flights.

Data and methodology

Calculated by FlyerIntel from 641 records of UA721 operating BOSIAD, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.

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