UA721
UA721 (United Airlines) is a multi-stop service on 9 routes, busiest Boston to Dulles. Of 760 departures recorded from October 2024 to July 2026, 86.7% left on time, according to the US BTS.
- On-time departures86.7%of 760 flights
- Average delay9.8 min
- July 202631▲ 0.0%vs July 2025
- Cancelled1.8%
- Legs flown under this number9
Recorded departures by month
All legs under this number combined; see the leg table.
The most recent periods19 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 31 | 31 | 0.0% |
| February | 30 | 42 | ▲ 40.0% |
| March | 31 | 35 | ▲ 12.9% |
| April | 30 | 30 | 0.0% |
| May | 56 | 31 | ▼ 44.6% |
| June | 52 | 30 | ▼ 42.3% |
| July | 31 | 31 | 0.0% |
| August | 31 | – | – |
| September | 30 | – | – |
| October | 31 | – | in progress |
| November | 30 | – | – |
| December | 31 | – | – |
| Year to date (Jan–Jul) | 261 | 230 | ▼ 11.9% |
according to the US BTS · October 2024 → July 2026
On-time departures by month
On time = departure within 15 minutes of schedule. Non-cancelled flights with a recorded delay only.
The most recent periods19 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 85.7% | 82.8% | ▼ 3.4% |
| February | 86.2% | 87.5% | ▲ 1.5% |
| March | 87.1% | 85.7% | ▼ 1.6% |
| April | 90.0% | 96.7% | ▲ 7.4% |
| May | 82.1% | 96.8% | ▲ 17.8% |
| June | 88.5% | 93.3% | ▲ 5.5% |
| July | 74.2% | 79.3% | ▲ 6.9% |
| August | 83.9% | – | – |
| September | 82.1% | – | – |
| October | 80.0% | – | in progress |
| November | 82.8% | – | – |
| December | 77.4% | – | – |
| Year-to-date average (Jan–Jul) | 84.8% | 88.9% | ▲ 4.8% |
according to the US BTS · October 2024 → July 2026
Average departure delay by month
according to the US BTS · October 2024 → July 2026
Cancelled departures by month
The most recent periods19 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 3 | 2 | ▼ 33.3% |
| February | 1 | 2 | ▲ 100.0% |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 2 | – |
| August | 0 | – | – |
| September | 2 | – | – |
| October | 1 | – | in progress |
| November | 1 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 4 | 6 | ▲ 50.0% |
according to the US BTS · October 2024 → July 2026
This is a historical record of departures already flown, not a forecast for your flight.
Several legs: the headline figure averages all of them. See the leg table.
Cancellation share
- Not cancelled 98.2% 746
- Cancelled 1.8% 14
Share of all recorded flights in the period, all legs. · Oct 12, 2024 → Jul 31, 2026
On time, leg by leg
Departures within 15 minutes of schedule; small figure = departures recorded.
Legs flown under this number
5| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| BOS IAD Boston Logan International Airport – Washington Dulles International Airport | 663 | 12.2 min | 86.3% | 530 |
| ORD BOS Chicago O'Hare International Airport – Boston Logan International Airport | 1,391 | 3.0 min | 88.2% | 93 |
| IAD MSY Washington Dulles International Airport – Louis Armstrong New Orleans International Airport | 1,537 | 10.5 min | 85.3% | 37 |
| IAH BOS George Bush Intercontinental Airport – Boston Logan International Airport | 2,567 | -0.9 min | 94.4% | 36 |
| LAX IAH Los Angeles International Airport – George Bush Intercontinental Airport | 2,215 | -1.4 min | 94.4% | 36 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 25 | 25 | 92.0% | 0 |
| November 2024 | 58 | 58 | 93.1% | 0 |
| December 2024 | 33 | 33 | 97.0% | 0 |
| January 2025 | 31 | 28 | 85.7% | 3 |
| February 2025 | 30 | 29 | 86.2% | 1 |
| March 2025 | 31 | 31 | 87.1% | 0 |
| April 2025 | 30 | 30 | 90.0% | 0 |
| May 2025 | 56 | 56 | 82.1% | 0 |
| June 2025 | 52 | 52 | 88.5% | 0 |
| July 2025 | 31 | 31 | 74.2% | 0 |
| August 2025 | 31 | 31 | 83.9% | 0 |
| September 2025 | 30 | 28 | 82.1% | 2 |
| October 2025 | 31 | 30 | 80.0% | 1 |
| November 2025 | 30 | 29 | 82.8% | 1 |
| December 2025 | 31 | 31 | 77.4% | 0 |
| January 2026 | 31 | 29 | 82.8% | 2 |
| February 2026 | 42 | 40 | 87.5% | 2 |
| March 2026 | 35 | 35 | 85.7% | 0 |
| April 2026 | 30 | 30 | 96.7% | 0 |
| May 2026 | 31 | 31 | 96.8% | 0 |
| June 2026 | 30 | 30 | 93.3% | 0 |
| July 2026 | 31 | 29 | 79.3% | 2 |